wlp002 vs wlp007, house yeast switch, and diacetyl from dry hopping

[barleyfreak]

I've been using 002 as one of our house yeasts for our flagship IPA, porter, stout and a few others. I occasionally get some diacetyl issues from the IPA or others that are dry hopped. Never the porter/stout or any beer where there is no dry hopping. I am considering changing this house yeast to wlp007, the dry English. I am wondering if anyone has made the switch from 002 to 007 and can describe any changes/improvements? Or just loves 007 and genuflects in its very presence.

Also, White Labs has this on their site for the 007,

As-is Diacetyl
45.31ppb
Total Diacetyl
59.33ppb

and this for the 002,

As-is Diacetyl
150.52ppb
Total Diacetyl
180.13ppb

That is a considerable difference though I am not certain how to interpret it since my yeast health, temps, and yeast management regimen dictate reduction. I typically pitch at 64-66 for the 002 and let it free rise to 68-69 over the 4-5 days until FG. Diacetyl rest 2 days, soft crash to 58-60, harvest yeast, DH (4"port, top of FV), and let free rise back into the 60's for the dry hopping of ~5-7 days.

I do like the flavor profile for the porter/stout/ non-dry hopped beers I am making with the 002, but I'm thinking that if I switch, since it is drier, I may bump up the mash temps a bit to try to keep them similar. I would not mind a bit more dryness in the IPA, and definitely want to eradicate the occasional diacetyl though that very well may be my DH technique and timing more than simply yeast selection.

Anyway -- if any one has any sage advice (Don't do it!, or Do it!) regarding wlp007, I'd appreciate it.

Cheers,

[jscottAT4]

Sorry for the late reply - just stumbled across this thread.

For what its worth, we use 007 heavily and find it to be one of the strains most affected by diacetyl. We hold a steady fermentation temp around 67-68, and then rise +2f for a diacetyl rest which sometimes takes 2 days, sometimes longer.

We started doing forced-VDK testing to tell when the beer was ready to crash:

-Heat a sample to 165f for about 10 minutes We use a little sous vide water bath, or you can also microwave sample for 45-60 sec
-Chill to about 35f.
-Taste sample for diacetyl or mouth slickness

When tasted side by side with a non-heated sample, the results are really obvious; movie-popcorn buttery taste and/or mouth slickness means it failed the test and will be tested again the next day until it passes. We harvest our yeast after crashing, AFTER it has passed this test.

Interestingly enough, according to whitelabs, there is enough yeast in suspension to clean up diacetyl during rest without the need to leave flocculated yeast slurry in tank cone. Since we do a cold harvest, we have to leave the slurry there until it passes diacetyl testing and we can cold crash.

[barleyfreak]

Thanks for the reply. I have done the D-test before and perhaps I should now make it SOP. That said however, I really believe that it is the dry hopping that is introducing O2 and kick starting residual yeast and creating the diacetyl in qty that it apparently can't reduce. I have started to use the "hop cannon" approach to minimize oxygen in dry hopping and think I am on to something with this. I'll start the D-testing before AND after dry hopping and if I cannot get it to be gone each and every time, then I'll switch back to the 002, or try a different strain.

[Yeast]

what do you do for QA ? Are you absolutely sure your beer isn't simply infected? Hopefully at least simple microscopy at the very least. Wild yeast can be a culprit, I wouldn't assume pedio if it's a beer with those IBUs

[barleyfreak]

what do you do for QA ? Are you absolutely sure your beer isn't simply infected? Hopefully at least simple microscopy at the very least. Wild yeast can be a culprit, I wouldn't assume pedio if it's a beer with those IBUs

Well I don't have much in the way of a lab setup/microscope to do counts, etc. I will add though, that I have used the hop cannon now on 3 batches of the same IPA, all with the same yeast (or subsequent gens). In between them one batch was dry hopped. That is the only batch that I could detect diacetyl. And only AFTER dry hopping.

Also -- I never get diacetyl on batches dry hopped with wlp001.

[scarne78]

I have almost no experience with WLP002, however, I have plenty of experience with VDKs increasing during/after dry hopping. We saw that it was caused by the hops introducing O2 and converting the acetolactate to diactyl, usually increasing by 10 ppb. our pentanedione levels did not change

[Yeast]

Well I don't have much in the way of a lab setup/microscope to do counts, etc. I will add though, that I have used the hop cannon now on 3 batches of the same IPA, all with the same yeast (or subsequent gens). In between them one batch was dry hopped. That is the only batch that I could detect diacetyl. And only AFTER dry hopping.

Also -- I never get diacetyl on batches dry hopped with wlp001.

Do you re pitch the yeast from these IPAs?
If you do or you re-pitch in general.
Do you use methylene blue at least for viability determination or pH of yeast slurry for vitality indication?

IPAs are very stressful on yeast, Generally if I was harvesting 9 out of 10 times I wouldn't reuse the yeast from anything above 50IBU and above 6ABV because it would be 20% dead even if it was crashed right at terminal gravity and harvested ASAP.

stressed yeast have a hard time cleaning up after themselves. I would not assume bacteria because beers with above 20IBU are hard to spoil with diacetyl causing bacteria. Wild yeast isn't out of the question, hard to say without QA. re-pitching only increases problems, especially if you're flying blind.

Re-pitching from IPAs also stresses yeast and can just get worse with time.
I would harvest your yeast from a batch with IBUs below 30 to pitch IPA fermentation. or any fermentation for that matter.

[barleyfreak]

Do you re pitch the yeast from these IPAs?
If you do or you re-pitch in general.
Do you use methylene blue at least for viability determination or pH of yeast slurry for vitality indication?

I do repitch this yeast, primarily from, and for, our IPA. Do not have a microscope/lab set up. Do not measure PH, though I could certainly start. I am in the I-hate-my-current-ph meter camp though and should invest in a better quality one.

[xFutballFanx]

Recent research by the hops science lab at Oregon State have shown that hops have a small amount of diastatic power and can free up additional sugars during dry hopping. This, coupled with the oxygen introduction will certainly create more diacetyl. For this reason, I've started dry hopping after I harvest at 45-50, in order to minimize yeast activity. Also due to research by OSU regarding dry hop time/techniques, I've started using a VFD pump to gently recirculate the beer in the fermenter after dryhopping to fully dissolve and incorporate the hop pellets. This has resulted in a shorter diacetyl rest, and a shorter period needed of hop contact time for the flavor impact I'm looking for. YMMV.

Cheers!

[Jedi]

Biomat DAR eats diacetyl if you are in a pinch. Never seen it discussed here.

You get better hop dry aroma's with higher temps. What seems best to me is drop the yeast after fermentation is over, raise the temp for D-rest, wait a day, recirc dryhops at diacetyl temp for day 2, test, crash.