Question about WLP007

Of all the UK yeasts, that one (007) is probably the cleanest and driest...never gotten the big "D" from it. Oats can be kind of "oily"

Be patient, and don't refrigerate too soon. You are good.

 

All yeast strains produce diacetyl during the Lag phase and then 'process' the diacetyl during the Stationary phase. Give the primary fermentation sufficient time and diacetyl will be a non-issue.

Cheers!

 

Sufficient time is the way to get rid of diacetyl, but there's more to it. (Cut and paste time)...
To be more precise, diacetyl's precursor, alpha acetolactate, is made (with excess being dumped into the beer by the yeast) fairly early on. But the formation of diacetyl itself is an oxidation process that happens outside of the yeast cell. It continues until the alpha acetolactate is used up. The yeast absorb the diacetyl after it is formed, but it's not as if the yeast produce a one batch slug of diacetyl, switch gears, and then absorb it. My point is that diacetyl formation continues even after cleanup has started. It's the reason a forced diacetyl test can reveal new diacetyl even though there was no diacetyl taste before the test.

People think of a diacetyl rest as a way of reducing diacetyl, but it's really a way of making sure all of the diacetyl is formed and reduced.

 

Nice simplified notional curve, assuming it's supposed to represent diacetyl level. Looks like yeast manufacturer tutorial stuff. But even if the real curve looks just like that, diacetyl is still being produced after the peak diacetyl level is reached. It's just being reduced faster than it's being produced.

ETA: nice Ninja. I see with the reposted pic that it is supposed to notionally represent diacetyl level over time.

 

That's what I would recommend. If that doesn't work, you might consider adding yeast to the keg and see if they will clean it up. This would assume that the new yeast are in a state where they actually have a need for diacetyl, but I don't know of any diacetyl remover other than yeast.

 

When I have had doacetyl show up after kegging, I do this. It Sometimes has worked. When it has failed, I rehydrate some yeast like s05, let it get active in a small starter, pitch into the warmed leg. Wait. Drink. All is good.

 

Perhaps your best bet is to add a small yeast starter as suggested by @pweis909. Below is from the book Brewing: Science and Practice by Dennis E. Briggs, Chris A. Boulton, Peter A. Brookes and Roger Stevens

“The addition of actively fermenting wort to beer may reduce the diacetyl content.”

Cheers!

 

WLP007 is one yeast I would not expect to hear anything about diacetyl. If you leave this yeast in primary long enough you will not have this problem. I am not in any hurry so I leave mine on for three weeks. Hope you can clean your beer. Take care.

 

Jim, reminds me of a saying I have heard many times at work: we never have enough time to do the job right but we always have time to fix it.

Cheers!

 

The oxidation is temp dependent (no surprise) so the higher temps in the D-rest will speed Diacetyl formation, then reabsorption. Kara Taylor of White Labs did a talk on Diacetyl at the 2015 NHC, so AHA members can access that if interested.

 

Sounds like an engineer I had to answer to this week.