Fermentation Hopping & Biotransformations

I'm not sure it would be mentioned as anything other than (an early) dry hop.

 

Concept is fairly new to me…it was first introduced to me I believe on BA forum…maybe Jack Horzempa or Hopfenunmaltz pointing me to Peter Wolfe's dry hopping thesis from OSU. I interviewed Peter Wolfe who spelled out the concept to me and it was later reinforced during an interview with Matt Brynildson.

I'm interested to see the results of this experiment. Brewed the beer yesterday (so missed going skiing) and everything went extremely smoothly with all 3 fermenters split evenly. All three fermenters were churning this morning, so expecting fermenter dry hops to go in by Tuesday night.

 

I have been adding hops to the primary towards the end of active fermentation for maybe 3-4 years. I also add dry hops when the beer has cleared. I often do both.

 

I've also read it's only specific kinds of yeast that will do this biotransformation... British strains to be exact which is what it seems like a lot of the NE brewers are using.

 

Talks at the NHC/HomebrewCon by Matt Brynildson and Stan Hieronymus, Get Stans book for the love of hops. Do searches for his articles.

 

JC Tetreault from Trillium mentioned it to me in an email exchange I had with him about 2 years ago. I've been doing it ever since.
I do a day 3 addition and a day 7 addition and usually transfer on to hops in my serving keg on day 10. I feel like I hit all the possible benefits with that schedule.

 

Do you transfer to a keg to do your day 7 dry hop?

 

Lately no. I'll just keep it in primary until day 10. I used to transfer to a dry hop keg but the extra effort did not yield any noticeable difference to me.

 

So 3 additions then? What about your kettle additions?

 

I too dryhopping at day 3 and day seven. This process is hop breed and yeast strain specific. I have been wanting to use Apollo as it contains the most of a specific oil that is susceptible to biotransformations.

 

Hmmmm... I used to add hops to my fermenter regularly on day three or so, but at that point the primary fermentation was basically complete.

 

I have been all over the place with kettle additions of late. I used to do the typical small FWH and then nothing until FO followed by a last addition at between 160 and 180 degrees. Lately, I've been keeping that general schedule but reducing the amounts for each and putting those quantities back into conventional boil additions such as 30 min, 15, 10, etc. My thoughts being to hit the wort at every stage possible. So far so good.

 

I'm not sure I buy the whole biotransformation koolaid...if you add a lot of hops in the kettle and in the keg and wait for the sweet spot, it's pretty hard to beat... and simpler, imho

 

Below is a link to a technical article on "Biotransformation of hop aroma...

http://femsyr.oxfordjournals.org/content/3/1/53

Cheers!

 

Jack, what I find interesting is that for home brewers and a lot of commercial craft brewers, it seems there is still plenty of yeast in suspension for biotransformation to occur even if dry hopping in a keg.

Also, in Hops by Hieronymous, p.195, "Ting explained that this flavor does not result simply from hydrolyzed glycosides but also from the subsequent bioconversion by yeast and perhaps even enzymes and microorganisms in the mouth."

 

Or equivalently in a bottle if the homebrewer chooses to bottle their beers.

The unknown is whether active fermentation is required for this biotransformation process to occur. If this is indeed a necessary process then this biotransformation will occur in the homebrewer's bottled beers since the bottle conditioning process is a genuine fermentation process (a secondary fermentation).

There is also the comment that @JohnConnorforealthistime made that biotransformation is yeast strain dependent.

Lots of 'factors' going on here and based upon my readings to date the science is not completely settled on this topic.

Cheers!

 

Do you have some references (i.e., links) that you can provide here?

Cheers!