On the left is Fieldwork's St. Thomas IPA. It's a dank beer that the brewer, Alex Tweet, fondly called a fruity armpit. It has nice mouthfeel, and enough bitterness to break up the sweetness, and is a great beer that anyone should be happy to try.
On the right is Fieldwork's first North East IPA, Galaxy Juice. It's also a dank beer, but there's no talk of armpits. Because the grass and tartness are turned up to eleven, and you get that patented thick but crisp feeling you might get from a Tree House or Trillium or Threes or Grimm beer. It's also opaque or hazy, depending on your perspective.
The two beers are related. All Tweet had to do in order to go from St. Thomas to Galaxy Juice was change the malt profile a little bit, and the hops.
"You didn't fine the beer more?" I asked incredulously, thinking of the roadmap to the NEIPA.
"No," replied Tweet.
"You didn't change your filtering process at all?"
"Obviously you didn't add flour."
"Did you change your hopping timing and quantities?"
"Did you add more oats?"
"Did you change the water?"
Turns out, Galaxy Juice sorta is a relative of St. Thomas, except with a different hops (Galaxy instead of Mosaic) and a slightly different malt profile (more crystal and character). The yeast common to the two beers is Vermont Ale Yeast from Yeast Bay, and that's massively important to their differences, despite being common to both beers.
This beer has actually been made three times, in a way. The first time, the yeast aggressively flocculated and the beer was "bright clear" said Tweet.
Flocculation refers to the ability of yeast to aggregate and form large flocs and then drop out of suspension.
The definition of flocculation is, “reversible, asexual and calcium dependent process by which cells adhere to form flocs.” It is very important to understand the basics of flocculation and what affects it because the flocculation and sedimentation process is the easiest and least expensive way to get bright beer. Flocculation also effects fermentation performance and beer flavor.
Ideally, yeast will stay non-flocculent and in suspension until the desired final gravity is reached and then become flocculent and drop out of solution. As any brewer knows, yeast do not always cooperate with this concept. Yeast strains have different levels of flocculation characteristics from non-flocculent (1007 German Ale) to highly flocculent (1968 London ESB).
So the first time they used the yeast, the yeast aggressively flocculated and dropped out of the suspension, leaving a bright beer called Pulp Free, a play on the juicy IPAs, but with the haze taken out. The second time they used the yeast, they created St. Thomas, which was a slightly less bright looking fruity IPA that fits the normal Fieldwork zeitgeist in terms of look and mouthfeel. Maybe it has a little haze. The third time Tweet used the yeast, it was "tired" as the brewer put it, and it didn't flocculate as much, which left the beer closer to opaque. Voila Galaxy Juice.
I asked Nick Impelliterri from Yeast Bay about the flocculation. "We have noticed it gets a little more attenuative and a little less flocculant with each repitch," he admitted. "The attenuation is likely due to more active metabolic rate and harvesting technique, and the flocculation could definitely be a result of when yeast is harvested. Harvesting later would capture less flocculant yeast, which as I mentioned above, can also have something to do with attenuation increasing as they are in suspension and metabolically active longer."
Tired re-used yeast is not enough to produce this haze. Tweet had to harvest specifically for the less flocculate yeast, as Nick points out. "It's not stress so much as evolution. The yeast doesn't drop out like Cal, giving us a nice pitch. It's a bit thinnner and less flocculant, so we pitch that, so all the cells in the next beer are ones that struggled to flocc out, the next harvest a little thinner and less flocculant, and so on."
This change in yeast flocculation only had no discernable affect on the alcohol content of the two beers -- St. Thomas is listed at 6.7% ABV, and Galaxy Juice is 6.6% -- but the taste is pretty different. You get much more 'sting,' much more grass, and a different kind of thickness from the Juice.
So maybe that's the secret behind some of the most popular NEIPAs out there. Maybe less flocculating yeast is the ticket. It sounds a little strange, given all the other reasons we've been given in the past, sure.
But we've gotten used to strange. Before these last few years, nobody would have thought that beer on the right was an IPA at all, let alone one of the most popular substyle of beers in craft beer today.