alpha acid

Embracing Inefficiency in Craft Brewing

Good To Know

I used to do a talk titled "Embracing Homebrewing" (here it is on the Beersmith Podcast). Basically, rather than worry about replicating the exact process/results of a craft brewery, enjoy the things that you can do on a small scale without regulatory oversight (dosing in spirits, ice distillation, foraging) or  economic pressures (expensive ingredients, not worrying about extract efficiency) etc.

The more great brewers I talk to... the more I realize that Scott and I run Sapwood Cellars like a big homebrewing operation more than a small craft brewery. We're lucky that we have enough support and direct sales that don't have to worry too much about cost, time, or efficiency. This post dives into that a little deeper on the benefits of inefficiency using the six beers included in the upcoming shipment of our Out-of-State Shipping Club as examples! 


Variability: Flemish Gothic

Most mixed-ferm breweries have a single house culture they pull off a tank or set of barrels or a specific commercial microbe blend that they add to every batch of a given beer. It makes a lot of sense, it promotes consistency and you don't have to worry about blending/attenuation. However, for me it lacks the dynamic flavor options and variety in finished beers I love. Every time we brew a new sour base beer, we select a barrel with a culture that suits it, and add some to primary (along with a healthy Saccharomyces pitch). 

Flemish Gothic is a beer we blended from three different wine barrels, with three different base sour reds (Standard Red, Provisional Strength, Vin De Céréale) each with a different culture. That allowed us to dial in the acidity, malt balance, and level of Brett expression. It worked out that we did a three-year blend rather than the standard old/young blend done by Rodenbach and many other Flemish Reds. 


Flemish Gothic Tasting Notes

Smell - Real range, right from the start. Honey, leather, blackberry fruit leather, some dried hay of hops. Cocoa, Tootsie Pop. I could see Balsamic, but without the vinegar or nail polish. 

Appearance - Beautiful ruby red. Good clarity. Stable off-white foam, pours three fingers. 

Taste - Bright lactic acidity, with dried cherries in the finish. No acetic harshness in the finish. Mild perceived fruity sweetness. A little damp oak, but not aggressively woody despite the extended aging thanks to the well used barrels. Could have even used a little more. Slight licorice as it warms. 

Mouthfeel - Medium body, pretty smooth. Firm carbonation. Slightly oaky astringency. 

Drinkability - Really good, lots of malt/barrel/Brett character all working together without excessive acidity. One of my favorite sours we’ve done, right up there with Growth Rings. I’d like to blend something similar again in a few years. 

Changes for Next Time - A few people suggested more acidity, but I like it as is. It’s considerably more acidic than my recollection of Flemish Kiss from Commons. I’ll be looking forward to seeing how this one ages.


Effort: Gindicators 2024

Local in-season fruit is less expensive than buying IQF or Puree. What you are paying for with those is convenience and consistency. Buying locally requires figuring out who grows good produce, building relationships, and being on top of communication. For Gindicators, we sourced peaches, nectarines, and apricots as the summer progressed. I picked through them each day, processing and freezing the fruit that was ripe. Waiting on the rest. It's worth it for me to go that extra length to create the best stone fruit aroma possible! 

We paired that with a low-acidity (higher hoping rate) pale base aged in gin barrels. Stone fruit in general and apricots in particular bring a lot of their own acidity. After refermentation we blended in a 30 gallon "double gin-barrel-finished" higher-acid beer to add more gin character.



Gindicators 2024 Tasting Notes

Smell - Funky nose, damp hay Brett. As a result, it reads more saison-ish than our sours usually do. Melds in a fun way with citrus and rosemary notes from the barrels. Plenty of stone fruit, yellow peach especially, but leaves room for the other aromatics. Pez candy. Overall vibrant and varied. 

Appearance - Mild haze, bright yellow body. Sticky white head, good density. End of the bottle pour has some small yeast floaties. Seems like more yeast adhered in the bottle than usual too. Maybe the 58W3 from refermentaiton? 

Taste - Snappy acidity (malic?), glad we selected lower acid barrels for this one! Tastes more acidic than the >3.5 pH suggests. Lots of fresh apricot and nectarine on the palate. Minimal sweetness.  Juniper comes through in the finish, piney, Sprite-like. Faint bitterness from the higher IBU component in the blend. 

Mouthfeel - Firm carbonation. Light body, but not tannic or harsh despite the extended aging. 

Drinkability - The acid level is just about right for my tastes, lingers for a second, but then goes. 

Changes for Next Time - Not much to change on this one. I could be tempted to go up 25% on the fruit, it had a little more punch before we blended in the last 30 gallon gin barrel. Likely wasn’t necessary to repitch yeast so soon after refermentation on the fruit?


Process: Neologism 2024

We treat our sour beers with the same care and attention to sanitation and oxygen ingress as we do our Hazy IPAs. We purge the barrels and bottles with CO2, we fill the blending tank with water and push it out to remove all of the oxygen before transers. I think it really shows with the "vibrancy" of the aromatics we are able to achieve, especially in a dry hopped sour like Neologism. It goes into the blending tank on hops, and infuses cold for 48 hours before bottling. Since we can't do a water push out with the hops in there, we do the push out, then add the hops while purging with CO2. 

The only previous batch of Neologism was named to Craft Beer & Brewing's Top 20 of 2022... that was the only beer we ever entered into a contest of any type!


Neologism 2024 Tasting Notes

Smell - Expressive in the nose with the gin shining. Spruce tips. Barnyard. Hops aren't as "raw" as an IPA, but it is still fresh smelling. 

Appearance - Head is great (dense, long lasting). Slightly hazy golden. 

Taste - A little of that guava thing from the first batch is starting to come through, awesome. Pleasant acidity, tart, but not harsh. Gin is a little more savory-herbal than previous gin beers: rosemary, spruce, bruised basil. A touch of oaky-vanillin as it warms. 

Mouthfeel - Light astringency, firm carbonation. Light body. 

Drinkability - I think this one will continue to improve as the edges soften and the hops integrate more. Still wish we could get more of those McClintock Reserva barrels, but even the second use one really helped this one! 

Changes for Next Time - On point! Not this beer… but would still love to do a Tangerine-Gin and/or a Guava Gin at some point.


Risk: Honeymoon SZN

We try a lot of different things that "sound like a good idea." It would certainly be easier and more reliable to pick a slate of brands to make every year. We do rebrew/blend the same beers occasionally, but we don't have a firm schedule and we always try to leave room for inspiration based on what barrels, ingredients, and flavors we have available. 

For Honeymoon SZN we started with a collab we brewed at Olde Mother Brewing (Frederick). Wedding SZN was a rice ale with Nelson Sauvin, elderflowers, and Phantasm (along with a natural thiol-releasing yeast strain). We racked it to white wine barrels and let the resident culture work. I sourced muscadine/scuppernong grapes (indigenous) through a local farmstand that has a relationship with a grower in South Carolina. I knew it was a good idea from the aroma of my car on the way back - halfway between Nelson Sauvin and Strawberry candy!


Honeymoon SZN Tasting Notes

Smell - Muscadine really comes through. Lots of white grape juice. Some toasty-funk, but not a primary aroma when cold. Bridges the gap between the Nelson and Brett. 

Appearance - Clear. Very pale yellow. Good thick white head that doesn’t last long. 

Taste - Light acidity, even less than Life is Ridiculous. Good fruit character, unique, fresh. A touch of funky smoke in the finish I haven’t noticed before. No elderflower. 

Mouthfeel - Bright, light, spritzy. 

Drinkability - Good, could use a touch more acid, but it is very drinkable as is.

Changes for Next Time - Not sure muscadine is a star… would be fun with a light dry hop. Maybe with another fruit, stone fruit?


Time: Opulence 2024

We age our beers for a long time. Years ago I visited an established brewery that had just added a large barrel facility for sour beers. The brewer running it mentioned he had to meet a monthly production quota for packaged product. Just seems impossible for that to produce fantastic beer. Sometimes we go a month without bottling anything because the beer isn't ready yet... sometimes we are doing back-to-back runs because we don't want something to sit any longer! Opulence 2024 was supposed to be Opulence 2023, but the beer just wasn't ready for the cherries after 8 months in the barrel... but it was at 20 months! We had some leftover high-acidity beer from the previous batch of Opulence kegged off that we blended in with the "fresher" beer that was aged in second-use Cherry Brandy barrels. 


Opulence 2024 Tasting Notes

Smell - Reminds me of my homebrews (in a good way). Funk (leathery) really comes through along with cherry and almond. Cherry is really fun, lots of cherry pie, vanilla, and depth. Nothing weird from the cherry brandy barrels considering the previous use was Imperial Stout. 

Appearance - I wish the clarity was a little better, but the color is a pleasant amber-orange. Great off-white head. 

Taste - Mild acidity, could be a little higher. Detectable bitterness (maybe a hair high). Good cherry flavor, sour cherry pie, vibrant. 

Mouthfeel - Light astringency, which is disruptive to the smoothness. Firm carbonation, medium-thin body. 

Drinkability - It’s solid. I like the lower acidity compared to past batches, but the bitterness gets in the way. 

Changes for Next Time - I wonder if aged hops rather than fresh in the whirlpool would work without providing any weird aromatics? I really like what the Saaz in the whirlpool did for the aroma and balance (lower acidity), but the bitterness clashes with the acidity in flavor… despite being “only” 19 IBUs. Maybe better to go with some alpha acid extract in the tank?


Equipment: Stained 2024

One thing that has worked out well for us is having smaller equipment. Rather than be forced to do big blends, we have equipment that is sized for flexibility. For example, with Stained we age it on wine grapes and raspberries separately. I'm sensitive to the "seedy" flavor that comes from long contact time with raspberries... but I also enjoy the deeper flavors of extended skin contact on grapes. So for this batch we kegged off the raspberry half after two weeks, while the Merlot grapes continued aging for another month until we liked the flavor. This plays into having the time to taste and adjust the production schedule. 


Stained 2024 Tasting Notes

Smell - Berries, especially raspberries… go figure. Certainly reads Flemish Red, Rodenbach etc. rather than Lambic thanks to no big funk/rubber. 

Appearance - Bright red, thin off-white head drops quickly. Good clarity, but not brilliant. Very attractive. 

Taste - Raspberry popsicle, very bright. Suggestion of sweetness from the fruit and malt. THP has cleaned up. Jammy, not overtly malty, but it fills in the fruit. Firm acidity, no harshness. Wine is subdued, but layers complexity and roundness compared to straight raspberries. Clean, not much funk although there is some earthiness. Oak is subdued thanks to third-use barrels. 

Mouthfeel - Medium-light, firm carbonation. Not thin or watery, helps support the fruit. 

Drinkability - Good, plenty of acid for my tastes, delicious fruit. Could be a little more interesting microbially, but it works in the Flemish tradition. 

Changes for Next Time - Could shift more towards the Merlot? Surprised how much acidity it picked up despite the alpha acid extract in the tote.


Out of State Shipping Club

If you are interested in tasting these beers, please sign-up by 10/28! You'll be charged $146 to your card on file and expect to receive your beer the first week of November! Available in: WA, CA, OR, NM, NV, CO, MN, NY, DC, CT, NE, MA, FL, PA, NH, NJ, ID, TX, KS, IN, WI, MO, IA, IL, MI, ND, VA, RI, NC, and SC.

Includes one 500 mL bottle each:

Gindicators 2024: Gin-barrel-aged pale sour with Peaches, Nectarines, and Apricots

Flemish Gothic: 3-year Blend of Wine Barrel Aged Sour Reds

Opulence 2024: Sour Red with Fresh and Dried Sour Cherries aged in Cherry Brandy and Bourbon Barrels

Neologism 2024: Gin-barrel-aged and Mosaic Cryo Dry Hopped

Stained 2024: Wine-barrel-aged with Raspberries and Merlot Grapes

Honeymoon SZN: Wine-barrel-aged with Phantasm and Muscadine/Scuppernong Grapes


... read more
by admin 0 Comments

Noble Hops – Brewing Hop Groups

Good To Know
This week I take a look at the Noble hop group which are varieties of hops primarily grown in Continental Europe for use in European lagers and ales. Noble Hops The noble hops group are varieties of hops mainly grown in Central Europe that are characterizes by rich aroma and flavor. They are widely used […]
... read more
by admin 0 Comments

Are Thiols a Scam? Thiolized Yeast, Phantasm, and the Rise of Designer Beer

Good To Know
Thiols are the coolest thing in brewing hoppy beers since the invention of dry hopping. It seems like almost every collab Sapwood Cellars has been invited to brew over the last 18 months ends up "Thiolized": 3S4MP (Cosmic Punch IPA with Phantasm and Nelson Sauvin at Fidens), Cone Concentrate (Cosmic Punch DIPA with Simcoe at Other Half DC), Celestial Paradox (London Tropics IPA with Strata/Galaxy/Citra/Simcoe at Toppling Goliath), Yasokeee (Helio Gazer DIPA with Peacherine, Hydra, and Phantasm at Cushwa), and most recently Heisenberg (Helio Gazer DIPA with Galaxy/Nelson at Commonwealth).

So why all of the excitement from our fellow craft brewers? Obviously many of the collab requests are due to Scott's writing about and advocacy for thiols, but are they just something new that will be passé soon, or are these strains here to stay?


What Are Thiols?

Thiols are sulfur-containing compounds that are often potent aromatics. The ones brewers are excited about are tropical, winey, and citrusy, while other thiols are intensely unpleasant with aromas of garlic or rotten eggs... which is why the thiol mercaptan is added to natural gas to alert people to leaks. The "skunky" aroma of light-struck beer is also 3-methyl-2-butene-1-thiol.


Unlike many other beer aromatics that require concentrations in the ppm (parts per million) or ppb (parts per billion) many thiols have an aroma threshold in the range of 5-70 ppt (parts per trillion). This means that it doesn't take much of them to be apparent, but also means that it doesn't require "high" concentrations to become dominant. 


In terms of positive beer and wine aromatics, the thiols that get the most attention are 4MMP, 3MH, 3MHA, and 3S4MP. These have perceptions that range from passionfruit, to grapefruit, to rhubarb. These are the intense aromatics that give New Zealand Sauvignon Blanc wines their distinct aromas and are found free at low-levels in many New Zealand hops (as well as some other varieties from around the world).


Most of the thiols found in hops, malt, and other botanicals are bound and thus not active aromatically. Enzymes are required to free them. There are wine strains available capable of this, but getting those genes into brewer's yeast requires more work. 



Where Do Thiols Come From?

Bound thiols are found in both malt and hops, but levels vary widely. The bond in need of breaking comes in two "flavors" Cysteinylated (Cys) and Glutathionylated (Glu). The vast majority (90%+) in both malt and hops is Glu. The IRC7 gene in certain wine strains and Omega's Cosmic Punch can only work on the less common Cys. As a result, mash hops are most potentially beneficial for Cosmic Punch, as the enzymes in the mash (especially in the acid-protein rest temperature range) can help convert Glu to Cys. Luckily some less expensive hop varieties have the highest levels of bound thiols. We've used Saaz, Cascade, and Calypso with good results.


The more intense strains like Berkeley Yeast Tropics line and Omega's Helio Gazer, Star Party, and Lunar Crush can simply be added to a standard recipe with or without whirlpool hops. Rather than having more copies of the IRC7 gene, they have a wholly different gene which can free Glu-thiols directly. The IRC7 gene in Cosmic Punch is "sourced" from yeast, while patB Omega uses in the more assertive strains is from a bacteria (if transgenic CRISPR/Cas9 gene modification is a step too far for you). We fermented a kettle sour which only had a small dose of hexalone (isomerized hop extract for head retention) with London Tropics. The result was intensely passion-fruity, so much so that it could almost pass a fruit beer. 


GM (genetically modified) yeast strains aren't allowed in commercial beers in many countries (e.g., Canada, New Zealand). As a result there are labs working with wild isolates capable of freeing thiols for co-fermentations (e.g., CHR Hansen - it is primarily marketed for NA beers) and breeding strains with heightened thiol freeing capabilities (e.g., Escarpment). Omega initially worked on yeast breeding between English ale and a wine strain capable of freeing thiols... our trials with it (Designer Baby) were interesting, but had too much of the wine strain's idiosyncrasies present (poor flocculation especially). 



Pros & Cons of Thiol-Expressing Yeast

Pros:
-Intense aromatics that are otherwise impossible to achieve from hops, malt, and yeast
-Thiols have incredibly low aroma thresholds... measured in ppt (parts per trillion)
-Thiols are "free" no expensive hops or fruit required
-Thiols may help increase shelf-life by scavenging oxygen

Cons:
-Higher perceived "sulfur" aromatics are frequent in thiol-freeing strains
-Some brewers/consumers/countries prefer to avoid GM ingredients
-Thiols can be "one note"... is it really that different from adding a jar of passion fruit extract?
-Repitching the yeast doesn't make as much sense if you also want to brew English Ales, Porters/Stouts etc. 



More isn't (always) Better

Initially there was a focus on maximizing thiol concentration. This could include colder fermentation temperatures, mash hops, and engineering strains with more assertive genes. Like most aspects of brewing (or cooking) maximizing a single flavor compound doesn't usually result in the best overall flavor or balance. 


Thiols aren't typically a "primary" aromatic in beer, so a beer with over-the-top thiol concentration without anything to play off of can taste artificial. On the other hand, some of our heavily dry hopped DIPAs have tested at over 100X the flavor threshold for 3MH and still weren't the primary aroma thanks to competition from the "traditional" hop aromatics. From those test, I wouldn't worry about dry hopping removing all of the thiols.


As a general rule, I'd suggest using a more restrained approach to thiols in lighter/cleaner/simpler beers. It doesn't take much to add a unique twist to a lager or American wheat, where a double-dry-hopped DIPA or fruit beer may benefit from a much higher amount. In the end it's about your palate and goals for a beer. 


In my experience expressing thiols doesn't make every hoppy beer better. They add a distinct note that can greatly enhance the perception of passionfruit-type aromatics. That is a wonderful contribution when you are leaning into those flavors, but can be distracting or muddle other flavors. For example, I love the "mango popsicle" aroma of great Simcoe. However, with one of the intense strains like London Tropics or Helio Gazer in an all-Simcoe beer can become more generically "tropical" rather than varietal "mango." On the other hand, when dry hopping with passion-fruity Galaxy, or brewing with actual passionfruit the thiol note helps to enhance the existing aromatics. 



Phantasm

Hand-in-hand with thiol-expressing yeast goes Phantasm. It is essentially the dried and powdered remnants of the highest-thiol New Zealand Sauvignon Blanc grapes. As a result it comes with a high price-tag of ~$35/lb. It really doesn't smell like much before fermentation. Added to the whirlpool it adds a huge amount of bound thiols for the yeast to work on. 


During fermentation I detect a distinct "white grape" flavor and aroma that I don't get from other thiol-expressing ferments that rely on grain and hops alone for bound precursors. A lot of this drops out with the yeast however and the finished beers are rarely as distinct. To my palate the added expense is hard to justify in a highly-dry-hopped beer where the thiols are competing against other big aromatics. Unless you lean into those aromatics with a hop like Nelson Sauvin. I like Phantasm best when it is paired with actual white wine grapes, or in a simple base where it can star. 


We haven't used Berkely Yeast's "Thiol Boost" additive yet... but I'm just not that excited about a 15X increase on the already intense London Tropics level of 3MH. I'd be interested in herbs or additives that could push other unique thiol aromatics that we aren't getting from grain/hops. 



My Favorite Thiolized Batches

At Sapwood Cellars, we've brewed a few dozen batches between Cosmic Punch, London Tropics, Lunar Crush, and experimental isolates. I've enjoyed most of them, but a handful stand-out as beers I loved!


Cosmic Rings: Galaxy and Citra is one of our favorite combinations... but we have had a difficult time sourcing great Galaxy (that doesn't taste like honey roasted peanuts). This all-Citra double-dry-hopped pale ale starts with New Zealand Taiheke (Cascade) in the mash and kettle. It's one of our favorite whirlpool hops because it is low alpha acid and has a beautiful tropical aroma... not to mention a lower price compared to other New Zealand varieties like Nelson Sauvin and Riwaka. Then we ferment with Omega's Cosmic Punch which brings some tropical aromatics without becoming distracting or artificial. Finally we dry hop with Citra and Citra Cryo at a combined 3 lbs/bbl.


Tropical Pop: Kettle sour fermented with Berkeley Yeast London Tropics along with passion fruit and mango purees. Passion fruit is expensive, fermenting with London Tropics boosted the passion fruit aroma allowing us to use less without sacrificing the aroma intensity.


Field Learning: As a homebrewer I loved being able to dump a bottle of thiol-rich New Zealand Sauvignon Blanc into a keg of mixed-ferm saison. That wouldn't be legal commercially, but what we did for this collab with Bissell Brothers was to brew a restrained base with Hallertau Blanc in the mash and Phantasm in the whirlpool and age it in fresh Sauvignon Blanc barrels along with Bissell's house culture. After a year we added fresh Chardonnay grapes from Crow Vineyards here in Maryland. The tropical notes from the thiols survived barrel aging and gave the beer depth we wouldn't have gotten from grapes and barrel alone.



Takeaways

Are thiols a scam? No, but they also aren't an innovation that fundamentally changes what it takes to make a delicious beer. Consider a thiol-freeing yeast when additional passionfruit-type aromatics will enhance your beer. Don't worry about maximizing the thiols unless you they will be competing against other strong aromatics. 


I suspect that this is just the lead in to even more exotic genetically modified yeast strains (we have a pitch of Berkeley's Sunburst Chico which is modified to express high levels of pineapple-y ethyl butyrate). If you can produce a flavor compound without the cost, environmental impact, variability of growing it I suspect the economic pressures will be too great! That said, making delicious beers isn't about maximizing one or two compounds (in the same way that vanilla flavoring is inexpensive, but doesn't fully replace the depth and complexity of real vanilla beans). 




... read more
by admin 0 Comments

Hop Forms and New Hop Products

Good To Know
This week I take a look at some of the new hop products and forms of hops available to professional and home brewers. We’re fortunate to live in an era of hop forward beers, and brewers have a wide variety of products available to create great beers. Dried Hop Forms The vast majority of hops […]
... read more
by admin 0 Comments

Hop Utilization Models for Beer Brewing Compared

Good To Know
This week I take a look at the three major hop utilization models: Tinseth, Garetz, and Rager used to calculate bitterness in beer brewing. Bitterness Levels and IBUs The bitterness of a beer contributed by hops in the boil is typically estimated using one of three major hop utilization equations. All three attempt to estimate […]
... read more
by admin 0 Comments

Hop Cone Composition and Beer Brewing

Good To Know
This week I take a look at the hop cone and how its composition affects flavors when brewing beer. Hop Cone Composition If we look at the hop cone image (upper right, Source: Stan Hieronymus) we can see the various parts of the hop cone. The bulk of the compounds we are interested in are […]
... read more
by admin 0 Comments