Diacetyl - Too Short In Primary

[quaboagbrewing]

A friend of mine that has been a commercial brewer for many years recently started getting back into homebrewing to so he could create some pilot batches and eventually open his own brewery. Converting from commercial brewer to homebrewer has presented some challenges for him. He ran something by me recently that I wanted to get feedback from the forum on. His first few batches have been producing diacetyl. He described his brewing cycle like this to me:

"I've been going 3-5 days primary, then racking to 52 degrees for rest/ condition for 23-48 hours then 34 for a week"

I told him that I believe he needs to give this much more time in Primary to allow the diacetyl to work it's way out. My typical brewing cycles are minimum 3 weeks in primary at 65-68 degrees....if I do a transfer to secondary then I'll let it sit another 2 weeks there before kegging/bottling. I have brewed probably close to 50 batches using this cycle and never detected any diacetyl in my beers.

I have been brewing long enough now that I am never in a rush to get my beers into the keg (if I plan right I usually always have something ready to drink). I think the commercial mindset is to get the beer fermented, conditioned and bottled ASAP.

Just wondering if my simple advice to him was sound and if there is anything additional others may add.

Thanks.

 

[iBrewR]

Since he's a commercial brewer I'd assume that he's using a hydrometer and knows his beer is finished fermenting and that his pitch and temperature control are good. So, all he'd really need is a couple of days diacetyl rest around 70 degrees before transferring. But it all depends on what yeast he's using and the gravity of his beer?

 

[PrinceOfThePoint]

Sounds like you have the brewing edge your commercial buddy. 3-5 days in primary is a joke if you ask me

Everything you said sounds good.

 

[VladOfTrub]

Diacetyl is rarely a problem in ale. Especially, when the yeast is good and enough of it is used and the wort has enough nutrients to support yeast. Pils and Lager might need a rest. When diacetyl forms after primary, it can be removed, temporarily. It will return and as time goes on the flavor becomes more assertive.

It's good that you are mentoring him in home brewing. What kind of beer was being brewed? No matter, ale or lager, the fermentation schedule needs to be dialed in.

Here's the thing. There is an enzyme that commercial brewers will add to mash. The enzyme blocks the precursors that are part of the diacetyl forming thing. No precursors, no diacetyl. Maybe, the brewery where he worked used the stuff and he might not have known it?

 

[quaboagbrewing]

The most recent batch was a 10 gallon IPA.....pitched 2 packs US-05 and kept in temp controlled chamber at 68 degrees for 5 days. I know that fermentation was off and running about 6 hours in but I don't know what the Brix reading was on day 5 when this was transferred.....but assume that based on the Brix determined that primary fermentation was completed and assumed that yeast in suspension would take care of diacetyl in a secondary fermentation. It's actually been fascinating discussing with him as I have not had a chance to really observe the full commercial brewing process up close (except for the occasional brewery tour). It's a good trade off as I get to learn more about commercial brewing and he gets to learn more about homebrewing.

 

[dyqik]

Don't big commercial fermentation tanks get a faster ferment because of the pressure at the bottom of the tank <half remembered from the "pressure fermentation" thread>? It may be that he's used to a faster completion and clean up from deep tanks. On a homebrew scale the only way to get close to that is with pressurized fermenters.

3 weeks primary probably isn't necessary for an IPA with US-05, but I'd let it sit for 2 weeks before starting the dry hopping etc. in primary.

 

[AnOldUR]

"I've been going 3-5 days primary, then racking to 52 degrees for rest/ condition for 23-48 hours then 34 for a week"

.....but assume that based on the Brix determined that primary fermentation was completed and assumed that yeast in suspension would take care of diacetyl in a secondary fermentation.

Not at 52 degrees. Try 72.