This post is one in a series following five brewers limiting themselves to a select set of ingredients and brewing several beers each with only those ingredients. The goal of these limitations is to push creativity and to see what can be done within the confines of a single set of ingredients. More about this concept can be found here. The ingredients chosen for this project were Maris Otter, White Wheat (malted), Light Munich, Amarillo, Nugget, WLP810 San Francisco Lager and WLP090 San Diego Super Yeast. The brewer must use all ingredients (with the exception of choosing one yeast strain). The rest of this series can be found here.

Author: T. Bowen

After deciding on ingredients for the Limitations Series, the first thing that jumped out to me was IPA or APA. However, I didn’t want to brew a “Standardtown” IPA/APA, but rather I wanted to use this opportunity to do some independent testing on biotransformation. Coincidentally, I brew a lot of NEIPAs, with just about every other batch I brew being an NEIPA. Although biotransformation is a big part of NEIPAs, I had yet to do any sort of testing on it in my homebrewery.

What is biotransformation (“biotrans”)? We homebrewers that like to get down in the weeds and nerd out on this stuff are very fortunate to have Scott Janish around, as he has done piles and piles of research into this topic (and I am very excited for his upcoming new book). At its most basic level, biotrans is the transformation of hop oils in the presence of yeast. More specifically, biotrans comes down to polyphenols and proteins. Proteins may seem familiar, yet it’s easy to not be as intimately familiar with polyphenols. I know I was not until I jumped on the haze train and floored the throttle.

In brewing, about 80% of polyphenols come from malt, and about 20% come from hops. Polyphenols have no aroma, and their primary impact is the perception of astringency. Typically, proteins in your mouth act as lubrication on oral surfaces. Yet, when polyphenols combine with proteins in saliva forming insoluble complexes, it robs the palate of lubrication and gives the puckering sensation of astringency. Anecdotally, I believe this is a key reason why many heavily hopped and dry hopped beers can seem a little astringent, at least to my palate.

What does this have to do with NEIPAs? As we know, most well-made NEIPAs are hazy, some to their detriment. When oxidized polyphenols react with proteins, they bind together permanently resulting in hazy beer, i.e., more proteins and more polyphenols lead to more permanent haze. Additionally, one key similarity in most (though certainly not all) NEIPAs is that they are dry hopped early, during active fermentation, e.g., at “high krausen.” And since we know that protein content in beer decreases during fermentation, it makes sense that dry hopping early would lead to more permanent haze in beer. In this way, high krausen dry hopping for the purposes of biotransformation and the haze commonly associated with fermentation dry hopping could potentially be related.

Recipe

With all of this information at my fingertips, I set out to test some of this research in my homebrewery. Another reason I wanted to test biotrans with these ingredients was that flaked oats was not available as an ingredient for this Limitations series. I always put a healthy portion of flaked oats in my NEIPAs, which boosts the content of protein in the grist significantly. So I wanted to see if I could have successful haze relying on the boost in protein from the wheat (and whatever I got from the Maris Otter and Light Munich). Additionally, I opted to use my standard NEIPA whirlpooling technique, which is a double whirlpool at high(er) temps and then low temps. I’ve been doing these low temp whirlpools for a while now and I absolutely love them for hoppy beers. I’ve found, anecdotally, that I get more flavor from the 170ºF WP, whereas I get much more saturated aroma from the 120ºF WP. Finally, for dry hopping, to test biotrans, I decided to split the batch evenly, with one half getting a double dry hop and the other getting the standard single, late dry hop. Here’s where I landed:

Mashed at 153ºF for 60 minutes 82% Maris Otter (11 lbs.) 11% White Wheat (1.5 lbs.) 7% Light Munich (1 lb.)

Boiled for 60 minutes 1 oz. Nugget (13% AA) @ FWH [41.8 IBUs] 2 oz. Amarillo (7.9% AA) @ 170º WP, 20 minutes [4.8 IBUs] 2 oz. Amarillo (7.9% AA) + 1 oz. Nugget (13% AA) @ 120º WP, 20 minutes [0.8 IBUs]

Dry Hop – Batch A [Biotrans Batch] 1 oz. Amarillo + 0.5 oz. Nugget @ Day 2 1 oz. Amarillo @ Day 8

Dry Hop – Batch B [Late DH Batch] 2 oz. Amarillo + 0.5 oz. Nugget @ Day 8

Yeast: WLP090 (1.8 L starter)

Water: 3:1 chloride:sulfate

OG: 1.063

FG: 1.012

IBU: 48.9

ABV: 6.7%

Brew Day

My brew day was fairly uneventful as far as brew days go. After mashing in, I checked temp and was perfectly satisfied even though I came in one degree shy of my target mash temp of 154ºF. I attribute this to the fact that this was only my second brew day with my new pump and I’m still on the learning curve figuring out temp losses and such pumping from my HLT to my MT.

The boil proceeded as usual and as soon as I cut the flame, I briefly ran water through my immersion chiller to drop the temps to 170ºF, tossed in the first WP hops and let the pump recirculate for 20 minutes. I don’t typically lose a ton of heat during my WPs, so after the first, I briefly ran the chiller again to get me down to 120ºF for my second and final WP.

Following the second WP, I finished chilling and racked 2.5 gallons of wort into each fermenter.

Both fermenters went into the ferm chamber where I split the starter evenly between the two and let them ferment out at 68ºF.

Fermentation kicked off relatively quickly and aggressively, as San Diego Super usually does. I added DH1 to Batch A on Day 2 of fermentation, at “high krausen.” Both beers were showing signs of being done, so I added DH2 to Batch A and the lone DH to Batch B on Day 8. I let them sit on the dry hops for 3 days, and racked roughly 2 gallons of each to serving kegs.

Tasting

Appearance – Of note: I was having some trouble with a leaky poppet on the keg for Batch A, which is absolutely the reason for the significantly less foam. Both beers poured almost identically. If anything, Batch B (late DH) was ever so slightly hazier than Batch A. But this is so slight I attribute it to chill haze, nothing more. Both are golden amber, dark straw colored, like a west coast IPA.

Left: Fermentation Dry Hop | Right: Late Dry Hop

Aroma – Batch A has an almost Cheerios-like nose to it, slightly bready, almost sourdough note to it. There’s a slight stone fruit, possibly peach note, but overall the aroma is fairly subdued on Batch A (biotrans batch). Batch B has a more citrus-y nose, with some stone fruit in the background, and has significantly more aroma than Batch A.

Flavor – Batch A has a slightly sweet, sourdough flavor. On the back end of Batch A, I pick up something reminiscent of licorice. Batch B is brighter, rounder, fuller flavor, and not as sweet as the biotrans batch. I can pick up much more of the Amarillo-like citrus in Batch B. Overall, the standard, late dry hop batch far exceeds the batch hopped during active fermentation.

Discussion

I know that this split batch experiment was far from scientifically sound. Yet I am still shocked at the appearance of the biotrans batch compared to the late DH batch.

Left: Fermentation Dry Hop | Right: Late Dry Hop

You could read a newspaper through that glass. How did I not get any of my beloved NEIPA-like haze when I treated it and brewed it almost exactly like I do NEIPAs? I think this came down to yeast strain and grist composition.

There’s evidence that shows certain yeast strains are capable of biotrans and others are not; however, I was unable to locate a list of those known strains at the time of writing. Perhaps San Diego Super is not (or is less) capable of biotrans. The similarity in hop flavor would also indicate that not much (if any) true biotransformation occurred (at least relying on sensory alone, without any lab tests). I do know, in my homebrewery, I’ve used at least 8 different yeast strains in hazy beers. I’ve used standard commercial strains like WLP008 and WY1318. I’ve used strains I’ve propped up from commercial cans I’ve enjoyed. I’ve tried the dry yeast blend that Treehouse allegedly uses (S04/T58/WB06). I’ve used a Conan x 644 hybrid I got from a homebrewer in Finland. And lately my current favorite is the NEEPAH blend from Bootleg Biology. My point is, all of those yeasts made hazy beers when I wanted them to. This is the first time I’ve attempted (for the most part, sans grist) to make a hazy beer and failed. Although, to fully test WLP090’s ability to create a hazy beer, I would like to try it again in my standard house NEIPA recipe.

Another culprit, I believe, is the protein, or lack thereof, in the grist. I always use a healthy portion of flaked oats (~20%) in my NEIPA grists which boosts the protein content significantly. With these beers, the majority of malt proteins came from the wheat malt. I know what you’re thinking: plenty of people make hazy beers without any flaked adjuncts, and you’re absolutely right. Treehouse supposedly does not put any flaked anything in their hazies. Whether or not the lack of protein contributed to my lack of haze is undetermined. But I do think more protein would have helped haze formation.

Although this experiment did not yield much fruitfulness, it was interesting and has motivated me to do more trials in this area and I plan to split more batches in the future when I brew my standard NEIPAs.

Recipe Comparison

Note: Some disparity in IBU contributions for flameout and whirlpool additions will exist in the chart below due to variation in recipe calculator software amongst contributors.

Beer 1 Beer 2 Beer 3 Beer 4 Style Hoppy Wheat Pale Ale/Lager IPL NEIPA/IPA Maris Otter 34.4% 50% 50% 82% Light Munich 5.5% 25% 41% 7% Wheat 60.1% 25% 9% 11% Hop Addition 1 28.7 IBUs Nugget (60 min.) 41.3 IBUs Nugget (First Wort) 21 IBUs Nugget (30 min.) 41.8 IBUs Nugget (First Wort) Hop Addition 2 5.5 IBUs Amarillo (5 min.) 5.8 IBUs Amarillo (15 min.) 23 IBUs Amarillo—30 min. Whirlpool 4.8 IBUs Amarillo (20 min Whirpool at 170F) Hop Addition 3 7.1 IBUs Nugget (5 min.) 2.3 IBUs Nugget (5 min.) N/A 0.8 IBUs Amarillo & Nugget (20 min Whirlpool at 120F) Hop Addition 4 16.8 IBUs Amarillo—30 min. Whirlpool 0 IBUs Amarillo (flameout) N/A N/A Hop Addition 5 22 IBUs Nugget—30 min. Whirlpool N/A N/A N/A Dry Hop 2.5 oz. Amarillo, 2 oz. Nugget (10 days) N/A 2 oz. Amarillo @ Day 1; 2 oz. Amarillo @ Day 4 1 oz. Amarillo & 0.5 oz. Nugget @ Day 2, 1 oz. Amarillo @ Day 8; 2 oz. Amarillo & 0.5 oz. @ Day 8 Yeast WLP090 at 64°F, raised to 70°F WLP090 at 66°F, raised to 72°F; WLP810 at 63°F WLP810 at 65°F, raised to 68°F WLP090 OG 1.059 1.058 1.050 1.063 FG 1.012 1.009/1.014 1.010 1.012 ABV 6.2% 6.5%/5.8% 5.3% 6.7%