Anyone notice diacetyl from Big dry hopping?

Over 14 years at this site and I thought I had seen it all. And trust me, I've seen a lot. Never bothered to ignore a member until just now.
That has got to make you proud.

 

@Brew_Betty

I have read in the past a few articles/write ups that mention the increase in grassy/earthy notes if in contact with the beer too long. Perhaps that is the character that I pickup as muddled? So while you are trapping all the oils/aroma in the keg, over a few weeks when the green matter breaks down or whatever, perhaps that is what I pickup as the fall off of my IPA. Not so much that the aroma is gone, just changed (for the worse). It doesn't sound too far off.

@thebriansmaude sent me this article: http://scottjanish.com/examination-...s-for-achieving-maximum-hop-aroma-and-flavor/

Which also had an interesting tidbit, relative to oil levels in the samples of hopped beer (done in a keg):

"Here we can see their results, which show the concentration of linalool tested at 3 different stages of the dry hop (day 1, day 4, and day 7). Interestingly, the oils were almost completely extracted on the first full day of dry hopping and even decreased after day 4! Nearly identical results were found when the myrcene concentration levels were tested (second graph), with myrcene dropping after day 1".

I tried to look for more data, but in my short look don't see too much on what contact times do in various situations (fermentation dry hop, keg hop, spunded kegs, etc...). But maybe this is a clue to why keg hopping may, or may not be, ideal... Especially relative to how quickly it takes to drink that entire keg. In my case, my beers are usually on for an average of 2-3 months... While other people I'm sure go through their kegs in just 3-4 weeks.

And I recall back with my old techniques, not noticing the same type of drop off as I do with the newer methods detailed in my previous post.

 

Also, thousands of breweries have just as good, or better results without having hops in kegs/bottles/cans (usually...). So I'd say it's not exactly a requirement of making bright, aromatic beer. Its been done without for a long time now.

I never said hops are wrecking anyone beers. I said for MY beers, I dont like the end result and had better IPA before keg hopping.

Either way works of the brewer/drinker is happy. Just sharing my own experience, in which my own process is always evolving. Keg hopping just didnt do it for me, yet at least!

 

I think these are the important bits as to why you didn't get any hop creep or VDKs. Between cold crashing to 60F, dry hopping starting at 60F, cold crashing to serving temperature, and using 1098 ( http://www.wyeastlab.com/yeast-strain/british-ale ), I think that the opportunities for your yeast to ferment any sugars broken down by any hop derived enzymes are pretty low.

 

Fair enough. I don't use that yeast strain, so I really wouldn't know. What I do know, anecdotally, is that I use a Citra a LOT and I've never had any beer overcarbonate after dry hopping or produce VDKs. No actual science in that observation, but it IS one data point.

 

I believe in the mbaa podcast the guys talking about how the Citra they studied rarely caused any refermentation.

 

I think you're right. They found that each hop behaved a little different and Citra was one that didn't seem to have any effect at all. Palisade hop definitely had a huge impact on my beer. I doubt anyone knows the exact effects of most other hop varieties quite yet. Will take another decade or two to gather all that data and for people to agree that it actually matters (which it does).

 

Citra for the win. @Brew_Betty maybe it’s your appetite for Citra that has kept you from the creep experience you’re looking for.

 

I assume you mean me. I un-ignore after about 6-12 months or so. Only one (he whose name must not be spoken) has ever gone back on the naughty list after coming off.

FWIW, I'm enjoying your recent contributions and signal to noise ratio.

 

At the craft brewers conference this year there was a seminar on diacetyl after dry hopping. My memory of it: Allagash was noticing carbonation levels higher than expected in their hoppy table beer. They found that the beer was refermenting in the bottle. The cause was a small dose of alpha and beta amylase present in the dry hop. These enzymes causing a slow transformation of complex sugars into simple. The fermentation was tracked out over months and the fermentation never stalled.

Diacetyl comes into play because often times beers dry hopped post fermentation do not have an opportunity to clean up the refermentation byproducts.

 

Seems like a non-problem since the overwhelming majority of dry hopped beers are consumed relatively fresh. What time-frames were they talking?

 

Hmmm

 

So... Just looked back at the presentation. Allagash was seeing a 1 degree plato change in 3 weeks of conditioning. I remember the presenter saying that they had samples that they were still testing and the refermentation was still occurring. The batch in question was about a year old at that point

Oregon State saw a 1 degree plato drop in dry hopped/reyeasted Coors-banquet vs. a control reyeasted coors. This was over 3 weeks.

It seems as though the temp of these beers never went below 65F, although never fully clarified.

OSU measured amyloglucosidase, alpha amylase, and beta amylase. Found traces of all 3 in cascade hops. Amyloglucosidase is used in the production of Brut IPA


Edit: My personal experience is that you won't experience the same rate of change with beer in the 30-40F range.

 

Yes, I know, I've got one in the fermenter right now...@ 5 days it was @ 1.010...Co-pitched Imperial's Flagship and 5 ml of Glucoamylase...I'm going to go pull my 12 day sample right now...any guesses as to the gravity now? It's been at 65*F and started as a 1.059 OG Denali SMASH.

 

Yes, I would like to guess that it is now 1.000 with amazing pseudo body for something that light.(I just sampled it)...it was incredibly bitter 7 days ago (probably a truby sample), but smooth as a baby's butt now...I'm stoked!