Anyone listen to the latest Basic Brewing podcast with John Palmer regarding New England IPA?
I’ve been hearing about hop biotransformation for a few years, and back then there was little to no scientific study to prove it. Lately I’ve been hearing it a lot from several noteworthy brewing gurus. But according to Palmer, who cited a professor at UofO, biotransformation has only been proven in a couple wine strains and a couple Bret strains. Palmer is saying biotransformation is not occurring in ale or lager strains.
I suppose it could be successfully argued that SOMETHING is different when comparing beers dry hopped post fermentation with those dry hopped during fermentation, but who knows exactly what that is right now?
After hearing so many use the term biotransformation lately, I was believing that there must have been a new study proving it. I tried it in a couple pale ales and found no change or at least unnoticeable change, and on one brew day I did one batch at day 3 (during) compared to one batch for the last 3 days (post), and the post fermentation had obviously more aroma, but the same basic flavors. Meaning no noticeable new biotransformation flavors.
I’m curious if someone has study info that Palmer missed, or if this is another case of jumping on the band wagon just to find there is no band…
Well, when directly asked if he thought biotransformation was occurring in NEIPAs his answer was “No.”
I think that a lack of scientific evidence equates to “maybe”. If they can test for biotransformation in one sac strain, they can test for it in others, or most, or all of them. Not impossible, perhaps impractical.
The jury isn’t still out on this, actually it sounds like the detectives have not finished the investigation. If so, it’s a bit early to be claiming biotransformation is a thing in so many untested ales. There very well may be a thing, but do we know it’s biotransformation?
Edit: after listening yet again, he was being asked if biotransformation was the cause of the haze when he answered “No.” Then he went on to explain the lack of proof regarding ale yeast. Then he’s asked again if there is any biotransformation occurring bla bla… “to the best of my knowledge there is not”.
I wanted to make sure I was quoting him correctly in the right context.
Anyway, it’s in the interview. Again, my point is not to say biotransformation is not happening. My point is to ask where the studies are to support so many brewing authorities claiming it occurs.
I have a buddy who runs a Brewery in AZ, real smart kid, Siebel grad. He swears on biotransformation (I even heard him give a talk in it at a brewers conference I attended a couple years back) and I’ll tell you this: his hoppy beers are great. But he has to add more hops (he says) because of the method of hopping during fermentation. I simply feel like it is the amount of hops he uses that gets him those results. Just sayin’
It’s a statistics thing. If you always say that everything is baloney, then you are right every time you are actually served baloney. Just kidding. You are awesome!
Always predict the most outrageous and improbable thing. Everyone will assume you are just crazy. Then one day, something outrageous will occur, and you will be the only one who was right. Then they will all wonder if you were really the smart one all along…
Makes me wonder. Either Palmer and Shellhammer are unaware of that 2003 study, or it’s been disproved. I’m curious to see what Denny finds out from Shellhammer. I am hoping it gets proven because it’s a neat idea, but I’m not going to cherry pick to support something I’m wishful for
This Palmer interview was one of the best interviews on NEIPA I have heard so far. I agreed with him on just about everything he said. Where Palmer went wrong was that he failed to explain that there are different types of “bioconversions”. The word “bioconversion” is a rather generic word for any biochemical transformation that is biologically driven (Bioconversion - Wikipedia). Fermentation is a form of bioconversion, for example. The study that Palmer was talking about looked specifically at the enzymatic hydrolysis of glycosides, the Luk Daenen study. Luk Daenen published a study that found that out of over a hundred strains, there was very weak support for beta-glucosidase in S. cerevisiae, and one strain of Brettanomyces anomalus that had strong activity. So Palmer is right, there is no evidence for beta-glucosidase activity in ale yeast.
But that isn’t the full story. The 2003 study that was linked showed that there are other bioconversions happening. They HAVE to be happening because the hops don’t contain the compounds that are being found in the finished beer. There are a lot of different biotransformations of hop compounds during fermentation. In many cases, they don’t know how or why, but there is something going on. This is a completely separate issue from glycosides though (although in some of these papers, glycosidic reactions have been hypothesized as the cause).
Thanks for your thorough input! I’m looking forward to hearing what Denny finds out from the horses mouth. I sense that might pop up in a podcast… no rush.
In the end I just don’t want to be running round touting the awesomeness of something that, come to find out, doesn’t really exist. Home brewers are phenomenal at that. [emoji6]
It’s also possible that other factors are having an effect. I’d expect less oxidation from adding hops during fermentation. The two aren’t mutually exclusive, though.