Christmas Beers

I’ve never been good with present shopping during the Christmas holidays. Part of the reason is I’m not sure what to get and I usually procrastinate to the end. Moreover, I would rather give gifts that have a personal touch than buying the requisite gift card or shot in the dark. This year I decided to brew a batch for a few male members of my family and write a little blurb. Each gift was a case of 12 ounce bottles with personalized labels.

Ryan’s Renegade IPA

Not only is my brother-in-law, Ryan Nugent, an awesome husband to my sister, but he is a great friend as well. Social media guru and media development expert, Ryan used to work for Next New Networks back in 2011 until it was purchased by YouTube and Google and became YouTube Next Lab.

One of Ryan’s signature works has been the writing the Creator Playbook, which guides YouTube users on content optimization, audience identification, and strategies for developing channels on YouTube. Although Ryan likes many craft beers, he is a self-prescribed hop-head. No beer is too bitter or too hoppy for this individual. In keeping with tradition, I brewed my most bitter beer to date, a hop heavy IPA that clocks in at 100 IBUs (Tinseth). For the label art my wife, Kim, took some of his favorite story themes, iconic 19th century whaling and space travel:

Here is the recipe (7.0 gallons – split into two cases):

• 9 pounds extra light DME
• 8.0 ounces Crystal 20L
• 8.0 ounces Crystal 60L
• 1 ounce Chinook (13% AA) at 60 minutes
• 1 ounce Columbus (16.3% AA) at 60 minutes
• 1 ounce Centennial (10% AA) at 15 minutes
• 1 ounce Centennial (10% AA) at 10 minutes
• 1 ounce Cascade (5.5% AA) at 5 minutes
• 1 ounce Columbus (10% AA) at flameout
• 1 ounce Cascade (5.5% AA) at flameout
• 1 ounce Chinook (13% AA) at flameout
• 1 ounce of whole leaf Simcoe – dry hopped in primary for 2 weeks
• Yeast: Mangrove Jack’s US West Coast Yeast (no starter)

Bill’s Brown Ale; Garcia’s Brown Ale

With Ryan’s Renegade IPA I split the batch between Ryan and myself. This next batch was split between Kim’s father and my stepfather (I brewed both beers in one day). My wife’s father, Mr. Schaumloffel, whose name means foam skimmer for beer in German, is a great grandfather to Natalie and wonderful person to hang out with. Full of dry witty humor, Mr. Schaumloffel puts the charm in the term “old school” – he does things by the book and expects nothing less from anyone else. He grew up in the Rockaways of Long Island and worked as a steamfitter for the local union. He is so proud of these days that Kim decided to take the logo from his local 638 and convert it into a beer label:

My stepfather, Rene, came into my mom’s life after my parents separated, though they were friends in high school. Rene is a cool character – always mellow, relaxed and his personality always leaves you at ease. Rene is fantastic musician and an expert on all things Beatles. For his label art, Kim decided to play off an old Beatles album:

For both beers I asked Mr. Schaumloffel what his favorite craft beer is and he mentioned Brooklyn Brown ale. Although there is no recipe, I tried to clone the beer and found most of the ingredients – English and Belgian malts and hops along with some late American hops for flavor and aroma. Here is the recipe (6 gallons) which was split between Rene and Mr. Schaumloffel:

• 7 pounds extra light DME
• 1 pound Special B (180 L)
• 8.0 ounces of Caramunich II (57 L)
• 8.0 ounces of Chocolate Malt (450 L)
• 1.5 ounces of East Kent Goldings (7.2% AA) at 60 minutes
• 1 ounce of Willamette (5.3% AA) at 10 minutes
• 1 ounce Cascade (5.5% AA) at 5 minutes
• 1 ounce Cascade (5.5% AA) at flameout
• 1 ounce Willamette (5.3% AA) at flameout
• 0.5 ounce East Kent Goldings (7.2% AA) at flameout
• Yeast: Mangrove Jack’s US West Coast Yeast (no starter)

Brewing Notes:

This was my first time using Mangrove Jack’s dried yeast and I was pretty excited because of the different options that are available. The one downside to using this yeast was the huge lag time to the start of fermentation – 2.5 days. Every instinct of yeast biology and fermentation tells me this can’t be good. Long lag times equates to a yeast population that is understrength, stressed, and not ready to ferment a batch of beer. The yeast should be fermenting beer, not replicating and growing biomass. Interestingly, the beers came out pretty good (the brown ale is very close to the real deal), but I wonder if the beers could have been if I made a starter.

This was my first time making such a bitter IPA and at first I thought the beer was contaminated (phenols? astringency?) after trying it when the gravity reached 1.025. Turns out that the beer wasn’t finished fermenting and I tried it young, although the brown ale finished one week earlier (both beers were pitched at the same time with the same amount of yeast). The young off flavor was attributed extreme bitterness as I shook the carboy to get the dry-hops wet – the brown scum on the side of carboy went into solution as I shook it. This substance is potently bitter and gives the beer an astringent off-flavor. To save the beer I had to let the beer sit for another three weeks to allow those bitter resins to fall to the bottom and for the beer to finish fermenting.

Merry Christmas and Brew on!

Raspberry English Brown Ale

My recent brews have been off-centric, including a Butternut/Hubbard squash ale and a Coconut Porter. This next beer is an English Brown ale with a  secondary fermentation on raspberries. I made two past raspberry beers with good success, Biere a la Framboise d’ ete (raspberry summer beer) and Raspberry Dubbel Trouble. The dubbel was one of the earliest brews that I made and remember the beer being very fruity for a Belgian ale (no fermentation control) and one-dimensional with too much raspberry. The raspberry summer beer was brewed for my wedding in 2010 and was a blend between a Belgian Wit and a Blond Ale. This beer was better as the raspberry was complex and subtle with the pilsner malt clearly coming through.

This time I tried a different base beer, an English Brown ale. Malts, hops, and yeast are strictly British, and I only used two pounds of raspberries. Like my previous brews I bought fresh raspberries and froze them to break apart the fruit. I’ve never found contamination from the fruit to be a problem  as the high pitching rate, alcohol, and anti-microbial properties of the hops limit microbial growth. I did not rack the beer to secondary, but added the fruit after three weeks in primary. It then spent another two weeks re-fermenting.

Recipe (6 gallons):

• 12 pounds of Maris Otter Pale Malt (Thomas Fawcett)
• 1/2 pound of Crystal 20
• 1/2 pound of Crystal 60
• 1/2 pound of Crystal 120
• 1/2 pound of Chocolate Malt (Thomas Fawcett)

Mashed in with 1.3 qts of water per pound of malt at 158F and it went down to 152F after 30 minutes (target mash was 154F). Reheated to 158F and did not touch the mash until mash out. Raised temp to 168F and vorlaufed as usual. Did not check the first runnings. Sparged with 5.06 gallons of and collected 7.65 gallons of 1.054 wort and heated to 190F to pasteurize and left overnight. Boiled for 60 minutes:

• 2 ounces of Challenger (7.5% AA) at 60 minutes.
• 1 whirlfloc tablet and yeast nutrient at 20 minutes.

Cooled wort to 65F and pitched a one liter starter of WYeast 1335 (British Ale II).

Review:

Appearance: Pours a ruddy brown with a two finger head that dissipates to a thin lace that clings to the glass. Slight ruby highlights, but nothing compared to the previous beer which was a wit. Crystal clear with no visible yeast in suspension.

Smell: Raspberries in the nose, but not as fresh I would expect. Somewhat synthetic and muted, not freshly ripened fruit. Malt is nonexistent, but the yeast makes it presence known with some fruity esters of pear and strawberry.

Taste: Similar to the nose, the raspberry is one-dimensional. The flavor reminds of raspberry flavored candy, or raspberry flavoring as opposed to picked raspberries. Malt carries through nicely with toffee, biscuit, and toasted bread. Yeast flavors are also there but manifest as slight bubble gum. Mouthfeel and carbonation is medium.

Overall: Good but not great. The key difference between this beer and past brews was the selected raspberries. For the blended wit/blond ale, I grabbed local organic raspberries from a farmers market that were ripe. For this beer I bought run of the mill raspberries from my local supermarket. The beer actually reminds me of Sam Smith’s Organic Raspberry Ale, which I’m not a fan. The raspberry flavor itself  is not that dominant and tastes as if someone poured raspberry syrup in my beer. For the future I might try a different base beer and go back to local organic fruit.

Chocolate Coconut Porter

Coconut and dark beers (porters and stouts) can interact in a harmonious marriage. My favorite coconut porter is Minneapolis Town Hall Brewery’s Three Hour Tour. I was lucky enough to try this beer years ago by a friend who smuggled a growler on a flight from Minnesota. I had a few homebrew versions with a nice interplay between the roasted malts and sweetness from coconut – this has been on my list of “must try” brews for a long time.

A successful off-scale beer with weird ingredients should have a solid base beer and balance. For the base beer I decided to use my standard porter recipe which utilizes de-bittered carafa malt to keep the roast in check and a healthy dose of rye and oat malt to provide a full palate but dry finish. I increased the chocolate malt to get a heightened chocolate character and had a successful showing at a homebrew competition with my Chocolate Orange Cardamon Porter. For balance, I decided to take a wait and see approach – adding toasted coconut first to the hot wort as it cooled then adding more if needed. It turns out that while one pound of shredded coconut gave plenty of favor before pitching they yeast, fermentation completely scrubbed the beer of any sign of coconut. I then kegged the porter and dry-hopped with another pound of dried coconut shreds in a hop sack. The resulting beer was marvelous and one of my favorite beers I have ever made.

Recipe (5 gallons):

• 12 pounds Pale Ale Malt (Briess)
• 1 pound flaked oats
• 1 pound of flaked rye
• 1/2 pound of Carafa Special III (Weyermann)
• 1/2 pound Chocolate Malt (Thomas Fawcett)
• 1/2 pound of extra dark Crystal Malt (130L)

Mashed in with 1.3 qts of water per pound of grain 154F and went down to 151F over the course of 30 minutes. Second half of mash, the temps ranged from 154 to 152. Did not do a mash out, but my sparge temperature hit 170F. First runnings at 1.093 gravity and batch runnings at 1.030. Collected a total of 8.3 pre-boil wort at a gravity of 1.048. Boiled for 60 minutes:

• 1 ounce of Warrior (16% AA) at 60 minutes
• 1 pound of unsweetened coconut shreds, toasted at 350F for 15 minutes. Added this at flameout.

Collected a total of 7 gallons of 1.059 wort (only 6 gallons went into the fermentor) and cooled to 66F. Pitched a re-fed two liter stepped starter of Wyeast 1056 and oxygenated for 2 minutes. Interestingly, krausen and active fermentation had started by 3 hours, with little to no lag time. It is possible that fat content from the coconut could have provided extra UFAs to the yeast which subsequently lowered lag time.

Victuals:

OG: 1.059

FG: 1.012

ABV: 6.2%

IBUs: ~42 (Tinseth)

I brewed this beer almost three months ago and I have three bottles left. Below is a review of the beer:

Appearance: Pours pitch black and quickly froths to a two finger head. The head drops back to a thin lace within a short time. Honestly, I was surprised at the head formation since coconut is high in fat content and assumed that this would destroy the foam on the beer. Although not a rocking pillow that refuses to budge, it leaves some respectable lacing.

Nose: Baker’s chocolate and freshly cracked coconut. The aroma is dominant and enticing at the same time. Although one-dimensional, this is what I was looking for.

Taste: When cold, the beer does not give much in the way of coconut but the other malts pull through. Toffee, chocolate, slight roast and some darkened caramel notes. Mixed in the back-end is the coconut, but it is subtle and not overpowering. Finishes clean and the coconut lingers in a mellow fashion. The taste is reminiscent of chocolate covered macaroons. The bitterness is there but very gentle, providing just enough to hold everything together. Thanks to the oats and rye, the silky palate is full-bodied but the beer finishes dry.

Overall: I could drink pint after pint. I suppose I have penchant for coconut, but I actually hate eating it – the texture is off-putting. Several people have tried it and while some praised the balance others were surprised at the coconut screaming in their faces. I’ll chalk this up to different taste buds and keep this beer year around rotation.

Imperial Fall Harvest Ale

I have a few pet peeves with pumpkin ales. I cringe when I first see these brews coming out in July, fully stocking the craft beer aisles and pushing over valuable real estate of other well made craft beers that fit the season. A pumpkin ale without any real pumpkin should not push out summer ales and IPAs a week after the 4th of July.

Another issue I have with these beers are the overly spiced versions. Call me crazy, but if I want pumpkin pie, I would rather eat it! I know some people will chide me for this, but Southern Tier Pumking is way too spiced for my taste. My last rant is that pumpkin has very little flavor and other members of the squash family can provide wonderful notes to an over-hyped style of beer.

With my rant done, I must say I do like pumpkin ales. I know we are month away from Christmas, but this is the perfect time to be drinking pumpkin ales since the weather is getting colder. Something mildly spiced, dry, malty, and that has some vegetal squash like character is what I crave. Balance is key. Three years ago I brewed a pumpkin ale and I called Fall Harvest Ale, and have missed it ever since. I decided to resurrect this beer but increased the gravity and made some other minor changes. This time around I used a Hubbard squash and butternut squash. This beer is now keg conditioning and will be ready in time for Turkey day!

Recipe (5 gallons):

• Cut up one butternut squash and one Hubbard squash. Sprinkle with brown sugar.
• Roast for one hour (or until very soft) at 375F, tossing every 20 minutes.
• Let cool to room temperature before adding to mash

• 16 pounds Maris Otter malt
• 1.5 pounds of flaked rye
• 1/2 pound Crystal (40L)
• 1/2 pound Caramunich malt (56L)
• 1/2 pound of Honey malt
• 4.8 ounces Chocolate malt
• 1 pound rice hulls

Mashed in 122F with 1.3 qts of water per pound of grain and held for 20 minutes. Heated mash to 150F and held for 45 minutes. Mashing to 150F was difficult – it was so thick that mixing to avoid hotspots took forever. Added 0.5 gallons during this raise in temp to loosen the mash. Increased temperature even further to 168F for ten minutes for mashout. Vorlaufed as usual and obtained first runnings of 1.088. Batch sparged with 4 gallons of water and obtained a second runnings of 1.045. This is high for me and suggests that I have left over sugars in the mash. Pre-boil volume of 7.9 gallons and gravity: 1.070

Boiled:

• 2 ounces of First Gold at 60 minutes (3.3% AA)
• 3 tsp of cinnamon (flameout)
• 1 tsp of allspice (flameout)
• 1 tsp of nutmeg (flameout)
• 1/2 tsp of ground cloves (flameout)

Cooled to 66F with immersion chiller and pitched a starter stepped three times (3 liters total) of Wyeast British ale II (1335). Oxygenated for 3 minutes. The choice of yeast was a bit different this time around –  used the Whitbread strain last time.

What’s Been Brewin’ This Summer…

The last recipe that I posted was Jay’s ALTernative, an altbier dry-hopped with Tettnang. That beer came and went and I spent my summer brewing mostly hoppy ales with the occasional Belgian brew thrown into the mix. In an effort to play catch up, I’m going to post the recipes to four beers I brewed (all 5 gallon batches) and throw out some overall comments and thoughts for the future.

Honey Citra IPA

• 9 lbs Pale Ale Malt 2-Row (Briess)
• 5 lbs Pilsner malt (Weyermann)
• 1 lbs Caramel Munich 60L (Briess)
• 2 lbs Honey
• 1.00 oz Warrior [16.00 %] – Boil 60.0 minutes
• 1.00 oz Citra [13.40 %] – Boil 30.0 minutes
• 2.00 oz Amarillo Gold [8.70 %] – Flameout
• 2.00 oz Citra [13.00 %] – Dry Hop
• 2 liter stepped starter American Ale Yeast Blend (White Labs #060)
• Victuals: 6.4% ABV, 60 IBUs

This beer was more of a hoppy pale ale then an IPA and my main goal was to dry-hop in the primary after fermentation was done. I wanted to compare dry-hopping this way versus dry-hopping cold and in the keg. I was happy to find that I got great hop character from the Citra, but not much from Amarillo. I found that a vigorous fermentation usually blows off most late addition hop aromatics.

Pacific Jade Pale

• 12 lbs Pale Ale Malt 2-Row (Briess)
• 1 lbs Caramel/Crystal Malt – 30L
• 1.00 oz Pacific Jade [14.70 %] – Boil 60.0 minutes
• 1.00 oz Pacific Jade [14.70 %] – Boil 5.0 minutes
• 1.00 oz Pacific Jade [14.70 %] – Boil 0.0 minutes
• 2.00 oz Pacific Jade [13.00 %] – Dry Hop
• 2 liter stepped starter of American Ale (Wyeast Labs #1056)
• Victuals: 5.1% ABV, 46 IBUs

I bought this hop on a whim to try it out. The hop is of New Zealand origin and is the result of a cross between First Choice (New Zealand varietal) and a male Saaz. Billed as a versatile high alpha hop with fresh citrus character and notes of black pepper. I found the resulting beer to have a lager-like hop profile reminiscent of Hallertau. I found notes of gooseberry and herbal mint rounded out by a firm bitterness. I also experimented with dry-hopping both in the fermentor and in the keg; this technique gave even better results than the first beer.

Double Dry-hopped Pale Ale

• 1 lbs Caramel/Crystal Malt – 20L (20.0 SRM)
• 6 lbs Extra Light Dry Extract (3.0 SRM)
• 1.00 oz Warrior [16.70 %] – Boil 60.0 minutes
• 2.00 oz Columbus (Tomahawk) [14.00 %] – Boil 0.0
• 2.0 pkg American Ale (Wyeast Labs #1056)
• 1.00 oz Centennial [10.00 %] – Dry Hop (fermentor)
• 1.00 oz Citra [12.00 %] – Dry Hop 0.0 (keg)
• 1.00 oz Simcoe [13.00 %] – Dry Hop 0.0 (keg)
• Victuals: 4.6% ABV, 54 IBUs

A quick extract brew to satisfy my hop cravings. Not IPA strength, but very hoppy and floral. Notes of mango, passion fruit, pine, and citrus. At the beginning of the keg (first ten pints or so), the aroma was lacking and was all Citra (catty). Simcoe and Centennial finally found there way and gave an extra boost towards the end of the keg. Malt fell a little flat, but hard to compete with all of the aroma hops.

Wit’s End

• 1 lbs Rice Hulls
• 7 lbs Pale Ale Malt 2-Row (Briess)
• 6 lbs Raw Wheat
• 1.00 oz Saaz [3.20 %] – Boil 60.0 min
• 0.25 oz Sorachi Ace [12.60 %] – Boil 60.0 min
• 3 freshly zested oranges – Boil 0 min
• 2 liter stepped starter of Belgian Witbier (Wyeast Labs #3944)
• Victuals: 5.4% ABV, 17 IBUs

This beer was an experiment. I never did a cereal mash before and wanted to see if there was a noticeable flavor difference between flaked wheat (my wit beers have used this int he past) and raw wheat. Here are my brew day notes: “Mashed in at 130F with raw wheat and 1 pound of crushed grain (seven pounds total) and held for 20 minutes. Raised temperature to 154F and held for another 20 minutes. At this point the mash turned into a gelatinous goop. Boiled for 10 minutes with constant stirring to avoid scorching the grain. Added cereal mash to main mash and added to 2 gallons of water to hit 152F. However, as I added the rest of the grain, the mash settled into a thick brick. I added an extra 3 gallons of water (7.1 total) in the main mash to achieve a water to grist ratio thin enough for lautering. Mashed out at 172F to obtain a wort low in viscosity and to avoid a stuck sparge. First runnings at 1.062 with no stuck sparges. Collected 9 gallons at 1.042 gravity with a mash efficiency of 76%.” I did not notice a difference from my past brews, although the best experiment would be to brew another beer with flaked wheat, side-by-side. Yeast character was prominent provided some nice phenolics and spice to the soft wheat character. I could not tell I added oranges though.

What to Post after a Long Hiatus? An Experiment (Yeast Aeration) of Course!

My first post was in 2010, a standard bitter in honor of close colleague and astounding scientist that passed. I was in my fourth year as a post-doc at Columbia University studying how retroviruses (HIV, MLV) interact with the cells they try to infect. Time was in abundance, allowing me to brew in a small Bronx apartment while I gathered many friends and scoured the city for rare-to-find craft beers. I was able to ranch yeast and create a bank, isolate unique Brettanomyces strains, and collaborate with a world renown master brewer. Most importantly, I learned as much as I could about the science behind brewing beer. My time in academic research came to an end, and I married the most amazing woman I have ever known and met another one:

Natalie, my beautiful daughter, was a game changer for me. I assume that most father’s sense of their place in the world changes dramatically when your first-born looks straight into your eyes. Job hunting was next, and I was lucky enough to find a great job doing process development for vaccines at Merck. Moving and settling in, enjoying fatherhood, and trying to secure my family’s future has made me feel slightly old.

As a result of all of this stuff, my last post was back in May. I began to re-read some of my old posts and realized that this blog has been is linked to so many wonderful memories, both beer and non-beer events that I can’t possibly ignore it anymore. It’s posts serves as markers for my past. It is this for this reason I intend to start posting again.

And an experiment may be the best way to start posting again. As a recap, I began brewing experiment beers for a yeast class that I taught at Brooklyn Homebrew. Ben and Danielle were kind enough to provide resources and space for my scientific curiosities that kept brewing. In contrast to my work life, my style of experiments are not rigorous and grounded in statistical significance. The goal has always been to pique the interest of the vast majority of non-scientific brewers, both professional and amateur. More importantly, I do not have the resources at home to measure key components of the brewing process. Instead, my conclusions rely on the most important data point – the beer drinker.

I am teaching again, this time at a great homebrew store in PA – Keystone Homebrew. Jason Harris, along with Lou (store manager) has been kind enough to provide support and space for the yeast class and the experiment beers. I’ve already taught two classes, and the most recent one was this past Saturday (November 9th).

Oxygen

Yeast are facultative anaerobes, meaning that they prefer to use oxygen to produce energy efficiently through oxidative phosphorylation. In the absence of oxygen, yeast still produce energy but with the inefficient process of alcoholic fermentation. Luckily for brewers, yeast will almost always undergo fermentation due to the Crabtree effect, where in the presence of excess sugars, even if there is oxygen, yeast will produce ethanol and CO2.

The main reason yeast need oxygen is for the production of unsaturated fatty acids (UFA) and sterols. Both molecules make up the plasma membrane of the yeast cell. I won’t go into how they are synthesized, but sterols, such as ergosterol pictured below, is present in the cell membrane at much lower concentrations. Sterols  provides fluidity, making the membrane easier to bend and twist in shape.

Without sterols, UFAs would form rigid micelles, or droplets of fats. Importantly, this membrane fluidity allows for other vital proteins to be imbedded in the membrane. Some of these proteins are responsible for importing not only complex sugars (maltose, maltotriose), but vitamins, minerals, and cofactors. With poor cell membranes yeast will not tolerate increasing amounts of ethanol (which is why oxygenating that strong ale is crucial). Lastly, if the cell membrane is not healthy enough, bud scars from cell budding will take a toll on yeast health and restrict future growth.

What are the consequences of introducing too little or too much oxygen? It is best to think of it biochemically – that is, oxygen acts as an accelerant to certain biochemical pathways. For example, what I did not mention before is that O2 drives the synthesis of UFAs and sterols through a cofactor called Acetyl CoA.

I talk about this molecule a bit in my post on esters and it sits at the crux of critical yeast biochemistry. In this case, oxygen drives acetyl CoA to form lipids (UFAs, sterols). As more acetyl CoA is used to make UFAs, less is used to make esters and fusel alcohols. Therefore, beers that have more oxygen tend are cleaner in esters and fusels (think IPAs). Beers that have less oxygen will have more esters and fusels and are more fruity (think English ales). Increasing oxygen will grow more yeast cells as their membranes are super healthy and ready for budding. The increase in yeast biomass will add a bump in attenuation and may even thin out the beer since the yeast will be so active.

How much Oxygen?

Homebrewers have endless methods of adding oxygen such as shaking and splashing the wort, sloshing the wort from bucket to bucket, aeration with aquarium pump, and adding pure oxygen. I have heard lots questions since many homebrewers practice different techniques:

• How long do I shake?
• Should I use a drill with a whirl attachment?
• How long do you aerate with a pump?
• How long do you pump in pure O2? At what flow rate?

Let me answer all of these questions by saying that whatever works for your system that gives you the best beer is what you should do. Experimenting here is key. Brew that same pale ale three times, one with splashing, one with pure O2 (one minute), and one with pure O2 (five minutes).

In reality, as homebrewers it is very difficult not to introduce O2 once the wort is cooled. Simply transferring the cold wort into a carboy (without splashing) will add some amount of oxygen for the yeast to use, however this is far from ideal. Yeast need greater than 8 parts per million (ppm) to adequately ferment a batch of beer. Here are some numbers on different methods (keep in mind that O2 dissolves less in higher gravity wort) on an average batch of homebrew (5 gallons, 1.050 – 1.070):

• Shaking: 2 ppm
• Aquarium pump: maximum of 8 ppm
• 30 seconds pure O2: 5 ppm
• 60 seconds pure O2: 8-10 ppm
• 2 minutes pure O2: greater than 14 ppm
  • The above pure O2 is assumed to be one liter per minute.

Splashing the wort is a very ineffective method of introducing oxygen and may even introduce contamination. Notice that with an aquarium pump, air can only give you a max of 8 ppm, whether you pump for five or thirty minutes. Oxygen makes up only 21% of dry air so there is only so much O2 you can force into beer with this method. Moreover, 30 minutes of aquarium pumping may drastically reduce head formation since you will create so much foam. The only way to get enough oxygen into your wort is by using pure oxygen with a sintered stone.

Exactly how much O2 to add to your beer as this depends on many factors:

• Yeast strain (different O2 requirements for different strains)
• Wort gravity (need more O2 for higher gravity worts)
• Beer style

Beer style and flavor profiles generated from oxygenation is the most important factor to me and is the basis of my experiment. For example, will adding less oxygen enhance fruity characters of some english ales? Would my IPAs be cleaner with higher amounts of O2? Would there be any changes in fusel alcohols? Would the body be thinner or fuller? Textbooks and the internet can tell you the answers, but I feel it is better to experiment and find out for yourself.

For the experiment beer, I brewed an ESB in a ten gallon batch at Keystone Homebrew (OG: 1.056 with 40 IBUs):

• 1 lbs Crystal Light – 45L (Thomas Fawcett)
• 1 lbs Crystal Malt – 90L (Thomas Fawcett)
• 8.0 oz Pale Chocolate Malt (Thomas Fawcett)
• 12 lbs DME Golden Light (Briess)
• 2.00 oz Target [11.00 %] – Boil 60.0 min
• 2.00 oz Goldings, East Kent [5.00 %] – Boil 0.0
• 1.0 pkg British Ale II (Wyeast Labs #1335)

From this wort I split the batch four ways and provided different amounts of oxygen:

1. 30 seconds of splashing the carboy
2. 45 seconds O2
3. 5 minutes O2
4. 10 mgs of Olive oil

Sample (1) represents what a new homebrewer might do. I did not dump the wort between two buckets but rather sloshed the wort around in the carboy. This sample should have little dissolved O2. Sample (2) is my default oxygenation regimen at home – I usually add pure O2 for 1-2 minutes in a 5 gallon batch. Sample (3) was to observe any changes in the other direction with large amounts of oxygen added to the beer. When I did oxygenate this batch, the foam generated was huge, almost a 3 gallon tick mark. Unfortunately I did not have access to a medical grade O2 regulator and was unable to determine flow rate. I opened my regulator, what you typically find at homebrew stores, to its max setting.

Sample (4) may be the most interesting of all. I decided to mimic what Grady Hull, brewmaster at New Belgium, did for his masters thesis at Heriot-Watt University. The thesis can be found here and is generously hosted by brewcrazy.com. In a nutshell, he added dissolved olive oil to the yeast starter of a commercial batch of Fat Tire as a source of linoleic acid, a precursor to UFA synthesis and did not aerate the wort. The reasoning being that the oil provides all the UFA and sterol needs of the cell and you don’t need to add O2. The goal of the experiment was  to prolong beer half-life since oxygen has a severe staling effect. What they found was that the beer took a bit longer to ferment and was slightly more fruity. Independent tasters actually preferred this beer over the control beer.

For my experiment I added olive oil directly into the wort (no starter were made for each sample). Importantly, the amount of olive oil I added followed close to what Gary Hull did (1 mg per 25 billion yeast cells), which was exceedingly small (about a tenth the size of a pinhead). Moreover, olive oil will not dissolve in wort and must first be dissolved in 100% ethanol. For any homebrewers reading this – do not add a drop of olive oil to your beer. I had to weigh 1 gram of oil, dissolve it, and make a serial dilution until I had close to 0.1 ug/ml. Of this solution, I added 100 uls directly to the wort.

The beer is already fermented, bottled and was sampled at a yeast class this past Saturday (11/9/2013) at Keystone Homebrew. Similar to my past experiments, I will post flavor profiles from the students as data points in a future post.

Cheers!

Homebrew Review: Jay’s ALTernative

I brewed this beer almost 3 months ago when we first moved the Doylestown area in Pennsylvania. I rarely get to brew German beers, with my only two being a bock and a Bohemian pilsner. At some point I want to invest in a fermentation chamber to brew lagers, with an aim on German lagers, such as bocks, pilsners and a Schwarzbier. For now I have to settle for ambient temperatures of my unfinished basement during the colder months, which can hover close to 58°F. This altbier was an attempt to get as close to lager-like ale as possible. I veered a bit from tradition with this beer and dry-hopped with 2 ounces of whole leaf Tettnang to make something unique.

Appearance: Pours a toffee-like amber color with some slight haze. Even after some time (it has been two months in the keg), the dry-hops impart a polyphenol haze to the brew. Rocky 2-inch head that sticks around.

Smell: Herbaceous hop character assaults the nose with notes of pepper, mint, and chamomile. The Tettnang hopping makes its presence known and masks any sort malt and yeast character.

Taste: Follows the nose with a noble-hop type flavor. The hop character is resinous, earthy and spicy. Subtle one dimensional malt character, and a very clean ester profile coming from the yeast. Some mineral-like flavors round out the taste (interplay between hops and malt?). Average carbonation, dry, and medium mouthfeel.

Overall: I like it, but a weird beer for sure. Not exactly an altbier since the hopping was off the scale for this brew. The malt character was muted for me, but this could be due to the extract that I chose. However, the beer was very satisfying and thirst-quenching despite the aggressive hop profile. Next time I’ll lower the amount of hops and go all grain with a 50/50 mix of Vienna and Pilsen malt.

Farmhouse Saison #1

Phil Markowski, master brewer and author of Farmhouse ales wrote, “Saisons were meant to be refreshing. Therefore, it is wrong to imagine a syrupy brown beer of 10% alcohol. Rather, saisons were pale and light in alcohol and flavor. They were often sour and/or bitter”. Originating from Wallonia, saisons were brewed in the winter months using local farm ingredients (spelt and other forms of wheat) and stored until the farming months in early summer. Each farm produced their own unique beer and signature.

From these small and almost forgotten beginnings the American craft brewing movement has revived the style. There is a wide range of interpreting saison, with some being sour and quite funky, while other breweries make a beer that is very dry, mineral-like, and earthy. All great saisons have fruity esters produced from characterful Belgian yeast. My most favorite saison to date is Southamptons Peconic County Reserve Ale. This beer was brewed and aged in Chardonnay barrels before being bottle conditioned. Saison-Brett from Boulevard brewing Company is another fond memory. Although I have not had any, I have heard Hill Farmstead makes amazing saisons, Juicy and Ann are particular standouts. Brooklyn’s Sorachi Ace and Saison Dupont are benchmark examples that can be easily found on store shelves.

I have made only one other saison – Petite Spelt Saison. I never wrote a review for this beer as it was being consumed during my move. The beer went very quick to great reviews, and I’ve been missing something like this ever since. This time around I decided to ferment the beer with WLP 670, American Farmhouse blend. I wanted to make something that could store over a long period of time and slowly become sour/funky as this mix has Brettanomyces. Staying with tradition, I bottle conditioned the beer in champagne bottles.

Recipe (6 gallons):

• 10 lbs of floor-malted Pilsner Malt (Weyermann)
• 4 lbs of Flaked Wheat
• 1 lb of flaked Rye
• 8 oz Carared (20 SRM)
• 4 oz of Special B (180 SRM).

Mashed in at 122°F with 1.4 qts of water per pound of grain and held for ten minutes. Raised the temperature to 154°F and held this saccharification rest for 45 minutes. Mashed out at 168°F for ten mintues. Batch sparged and collected 9.3 gallons of 1.055 wort. Boiled for one hour:

• 1.75 oz of Sterling (7.0% AA) at 60 minutes.
• Yeast nutrient and whirlfloc at 15 minutes.
• 2 oz of Sorachi Ace (12% AA) at 0 minutes.

Cooled wort to 68F, aerated for 1 minute with pure O2 and pitched a one liter starter of WLP 670.

Victuals:

• OG: 1.050 (some wort was used for an experiment)
• FG: 1.010
• IBUs: 28.6 (Tinseth)
• ABV: 5.2%

Notes:

2/3/13: BREWDAY. Mashed in perfectly at 122F. Brought to 154F in 8 minutes. Holding at this temp in dead winter proved to be a challenge. Averaged at 154F, but temps swung from 148F to 158F. I’m unable to fine tune heat with the blichmann burner. First runnings: 1.094!! Second runnings: 1.037. Collected 9.2 gallons of 1.055 wort with a mash efficiency of 83%. After boiling, I added an extra gallon of distilled water to get a higher volume.

2/4/13: Pitched in the morning and by the evening there was vigorous activity.

2/6/13: Fermentation temps have been held steady at 69F throughout the most vigorous fermentation. After three days, krausen is starting to subside.

3/2/13: After one month in primary, the farmhouse ale is corked and caged under 2.6 volumes of CO2.

4/20/13: Had several chances to try this beer and I love it. Looking forward to seeing it change over time. Soft wheat dominates the pilsner malt. Lots in the way of fruity esters – peach, apricot, stone fruit. Some funk and a very slight sourness – barely detectable. Spritzy carbonation and thirst quenching. I will lay this beer down for months to come.

Jay’s ALTernative

I got the inspiration for this brew from a friend of mine at work. Dave, who was just getting back into brewing after a long hiatus, wanted to brew a malty ale and initially chose a German Alt. Knowing that his ambient temperatures were too high for an Alt fermentation, he opted for an ESB. The brew stuck in my head however, and since I never brewed one before, I decided to give it a go.

An altbier is historically a German ale of copper brown color, close to 4.5% ABV, clean in flavor but a with malty taste. The bitterness is firm  to hold the malt in check, and the head is a tall crown of foam. The word “Alt”, which means old in German, denotes a brew of old heritage coming from Rhineland, while modern altbiers originated in Dusseldorf in the 1800s.

What makes an altbier unique is it is one of the few ales that are fermented cooler than standard ale temperature at 55°C to 64°C. Under these conditions, ale yeast produce very little in the way of esters (more about esters in my last post) and off flavors. Moreover, they are aged in lagering tanks close to freezing. The result is a mellow and clean tasting beer that highlights malt and hops. Traditional ingredients for an altbier are slightly kilned German malts, such as Munich and Vienna malts, and German (noble) hops.

Unfortunately, I’ve only had two commercial examples to draw an accurate comparison for brewing my Alt, Alaskan Amber and Southampton’s Altbier. Both are OK, but nothing to get excited about and I  assume they are a far cry from the original. For my beer, I decided to focus on German hops and I dry hopped with two ounces of whole leaf Tettnang hops. Time was limited for this particular brewday, and instead of a blend of Munich and Vienna, I used dried malt extract. For my yeast, I selected San Francisco Lager (WLP810), which ferments cleanly in the upper 50s.

Recipe (6.0 gallons):

• 7 pounds of extra light DME
• 8.0 oz Caraaroma (150.0 SRM)
• 8.0 oz Carared (20.0 SRM)
• 4.0 oz Special B (180.0 SRM)

Heated 7.51 gallons of distilled water to 150F and added steeping grains for 30 minutes. Removed grains, and rapidly brought to a boil. Added only 1 pound of DME at the beginning of boil and the rest with 10 minutes left.

• 2.0 oz of Tettnang at 60 minutes (pellets, 4.5% AA)
• 0.5 oz of Hallertauer at 60 minutes (pellets, 4.8% AA)
• Whirlfloc and yeast nutrient at 20 minutes
• 1.5 oz of Hallertauer at 0 minutes (pellets, 4.8% AA).
• 2.0 oz of Tettnang (dry hop, whole leaf, continuously in the keg)

Cooled to 62F, aerated for one minute with pure O₂ and pitched a 1 liter starter of WLP810.

Victuals

• OG: 1.046
• FG: 1.012
• ABV: 4.5%
• IBUs: ~34.4 (Tinseth)

Notes:

 1/1/12: Brewday. Pretty straight forward – extract beer. Blichmann burner has been giving me problems in a small gust of wind – the flame blows out. However, found the best setting for maximum boil for Blichmann burner. Had to add back a gallon of water due to a high rate of evaporation. Pitched one liter starter at 62F.

1/2/12: Activity by 12 hours. By 24 hours, beer was throwing blow off. Temp at 61F

1/3/12: High krausen – temps at 62F.

1/4/12: Activity slowing down – 62F

1/6/12: Still some residual activity. Fermentation is lasting longer than I expected – could be due to the strain. Temps have remained at a constant 62F during the whole fermentation.

1/25/13: Racked to keg and carbed to 30 psi. Tastes malty but definite fruity esters are present. Lagering may remove this. Soft water doesn’t seem to be too detrimental. FG: 1.012 and an apparent attenuation of 73%.

2/6/13: Drinking great. Very sessionable. Nice malt flavor, decent head retention and lacing. Beer is still cloudy, mostly due to young age. Very clean ester profile, San fran yeast is a good yeast for pseudo lagers. German hops add quite a unique flavor to this beer – spicy, minty, and herbal. At first I thought the Tettnang dry hop was too grassy, but the flavor is mellowing out nicely.

2/19/13: Drinks very good and is a different flavor. Sessionable and has a unique ester profile.

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Review of this beer can be found here.

Hombrewer’s Lecture Series: Esters

A special “lecture series” often occurs at many academic institutions that is open to the public and scientific community. During my Ph.D. and post-doctoral training, this was called the “Dean’s Lecture Series” where world-renowned scientists would give great talks. In a nod to my academic past (as opposed to comparing myself to Nobel laureates!), I’ve decided to start a new series of posts called the “Homebrewer’s Lecture Series”.  This reflects my ongoing reading and learning since I have begun teaching a yeast class again at Keystone Homebrew Supply (expect more experiments). Each post will focus entirely on one aspect of yeast fermentation, how it can impact your beer, and what you as homebrewer can practically do to control it. As always, my target audience is not just for the hardcore beer chemist, but also for the homebrewer at home who wants to dive deeper into the science of beer.

Esters

This remarkable class of molecules is responsible for the fruity aromas and flavors found in fermented beer. Depending on the style of beer, esters play a major role. Top fermenting English ales often have more fruity esters reminiscent of apples, pears, and dark fruit. In contrast, American ales often have less esters allowing for hop flavor to shine. Bavarian wheat beers (Kristallweizen), contain large amounts of isoamyl acetate (banana/clove), while Belgian ales (Saisons) often a have complex mix of esters that make them stand out.

Reacting an organic acid with an alcohol by yeast during fermentation forms these compounds. In the example shown below, methanol is reacting with butyric acid, which smells like vomit, to produce methyl butyrate, which smells like apples or pineapples. I love chemistry.

Enzymes called ester transferases catalyze these reactions within yeast cells that are ultimately secreted from the yeast into wort. The biochemistry behind esters reflects the balance of metabolism inside the yeast at any given moment. Below is a basic diagram of yeast biochemistry during fermentation (Peddie et al., J. Inst. Brew., 1990, Vol 96, pp. 327-331).

Maltose (wort) is transported into yeast cells, converted into pyruvate and acetyl CoA. These two molecules, and acetyl CoA in particular, sit at a biochemical crux inside a yeast cell during fermentation. Any factor (temperature, wort composition, etc…) that affects the amount of acetyl CoA will also affect many other aspects of yeast biochemistry. For the discussion of esters, think of this pathway as a one-way flow. That is, anything that produces more acetyl CoA will eventually produce more esters. For example, with a higher concentration of maltose (high gravity wort) present the more acetyl CoA is produced, which feeds into ester production (hence why barleywines are often fruity).

Acetyl CoA:

The vast majority of esters in beer are produced from yeast during fermentation and are influenced by three things:

1. Wort composition and aeration
2. Yeast strain and health
3. Fermentation conditions

Wort Composition

As I mentioned before, the higher concentration of sugars you have, the more acetyl CoA is produced ending up with an increase in ester production. However, the availability of nitrogen also plays a key role. Higher amounts of nitrogen also pulls this pathway as well, producing more esters in addition to amino acids that are required for cell growth. In contrast, wort that is low in nitrogen slows the pathway and produces less esters. This can be seen in brews that use a high percentage of nitrogen-lacking adjuncts, such as light lagers. It is no coincidence that mass market macro lagers or extremely clean and neutral in taste.

Aeration

The presence of oxygen at the beginning of fermentation is absolutely required for yeast to produce unsaturated fatty acids (UFA) and have healthy cell walls. Acetyl CoA is required for this process and therefore any oxygen will draw acetyl CoA away from ester synthesis to UFA synthesis. In contrast, not enough aeration causes a buildup of acetyl CoA and ester formation. There is also some anecdotal evidence that oxygen increases the expression of some ester producing enzymes, although there is some controversy whether this is actually true.

Yeast Strain and Health

Yeast strain is probably the biggest factor of ester production during fermentation. Genetically, certain yeast strains are designed to turn on ester producing genes that can contribute to fruity overtones. English ale strains fall within this category. American ale strains, on the other hand, have a less capacity to produce esters. Lager yeast even less so. Some strains have been cultivated to produce one specific ester, such as hefeweizen yeast ability to produce banana and clove esters.

Although yeast strains vary in their ability to make esters, all yeast will produce a lot if they are stressed, including lagers. Yeast health is absolutely paramount to avoiding strange fruity flavors in your beer. Pitching an adequate amount of fresh yeast that has been plenty of glycogen levels and oxygen is critical in avoiding unwanted off-flavors. Pitching rates also have a minor influence on esters. That is, lower pitching rates increase ester formation, while high pitching rates tend to produce less. With my experiments I have found this to be highly dependent on yeast strain.

Fermentation Conditions

The state of beer fermentation has a large impact on ester production with temperature being the biggest factor. High temperature increases metabolic activity that in turn increases acetyl CoA production as described in above. The most critical time point to controlling fermentation temperature is about 1-3 days after pitching. Allowing a fermentation to go out of a specific temperature range is a definite way to get more esters. In a previous experiment looking at different fermentation temperatures, Wyeast 1388 produced more esters compared to lower temps. By reducing fermentation temperatures one can dramatically lower the fruitiness found in beer. Although not a concern for the vast majority of homebrewers, fermentation vessels can have a big impact on ester production. Tall, narrow vessels that produce lots of pressure will cause lower esters in the resulting beer.

In summary, there are many factors that can influence ester formation and I’ve summarized it here:

Can the Homebrewer Control Ester Production?

Short answer: yes. However, a dose of common sense is needed if you are concerned about esters in your beer. Do NOT skip oxygenating your wort just because this will increase ester production. You will have many other problems to worry about besides esters in this situation. Don’t avoid high gravity beers because you hate the over ripe fruit that comes along with it. If you want your English Bitter to have an awesome fruity bouquet, do not under-pitch to the point that fermentation starts three days post-pitch. Changing the dial on esters is more of a subtle affair and I’ll list what we as homebrewers can practically do to control it (in order of importance):

1.  Choose the right yeast strain. The most important factor in changing ester profile. Use yeast genetics to your advantage and if you want a clean English IPA, use an American ale yeast paired with British malts and hops. If you want to brew a fruity “east coast” IPA, an English ale yeast may be your cup of tea.
2. Fermentation temperature. Controlling temperature during fermentation is a great way to rein in those esters. However, if you heart is dear to American ale yeast for your IPAs, but you want some extra fruitiness, don’t be afraid to go beyond the manufacturers suggested temperature range. Likewise, if you want “lager-like” character from Wyeast 1056, don’t be afraid to ferment below 60F. Remember, increasing metabolism (yeast growth) drives ester production
3. Pitching rates. This last option is really a distant third to the ones above. The reason I say this is because drastically changing pitching rates can have other effects on your beer and stress the yeast in different ways. Having said that, minor changes can have a positive change to ester production (or inhibition). An English ale that gets a slightly lower pitch rate (0.5 million cells/ml of wort/degree Plato, for example) will slightly bump esters. The same holds true for overpitching.

I hope this primer on esters is somewhat beneficial. Keep in mind that controlling esters is somewhat of a balancing act and interconnected with other molecular compounds found in beer. In next lecture series I will write about fusel alcohols, how they relate to esters, and how you as a homebrewer can reduce or increase them.