Diacetyl With 1214

[JaseH]

Currently on my second attempt at a belgian abbey style ale using wyeast 1214 and its looking like I'm producing another diacetyl loaded beer. I've never had issues with diacetyl before and am not sure what I'm doing wrong with this yeast to get it.

First beer was a Tripel

OG 1.083
FG 1.010
82% Pils, 10% Munich, 6% table sugar and a touch of carapils.
Pitched 3L active starter of 1214 @20C and ramped up to 22C over a couple of days.

It fermented out to 1.011 in about 3 days, after 1 week had settled at 1.010

At this point I needed the ferm fridge for an APA so dropped the temp back to 18C - I figured this is where I went I wrong with this one, not giving it enough time at elevated temps to cleanup? Although it spent another couple of weeks in the primary before I cold crashed and bottled. Not a bad beer but definite diacetyl now that it has been pointed out to me and I can recognise it.

My current attempt is a Dubbel which I pitched at 20C and raised to 25C over a few days.

OG 1.060
FG 1.009
Pils, Munich, Special B, Melanoiden, Crystal and D2 Candi Syrup
Again pitched 3L active starter of 1214, another rocket ferment down to 1.011 in 3 days. Tasted buttery at FG so I've kept it at 24-25C now for over a week after FG, but am still tasting what I think is quite strong diacetyl. Once again I've got another APA to go into the ferm fridge so have had to drop the temp back to 18-19C

Only things I can think of that I'm doing wrong to get diacetyl is:

1) overpitching
2) not enough oxygenation.

But the rocket ferments down to FG tend to point to there being no problem with yeast health?

Am I just not leaving it long enough to clear up? I thought a few days after FG was usually enough for the yeast to tidy up? Any ideas?

 

[razz]

Where did you get the yeast from Frothie, was it a new pack or did you have some saved from a previous batch?

 

[JaseH]

Where did you get the yeast from Frothie, was it a new pack or did you have some saved from a previous batch?

Originally started with a new smack pack for the Tripel, which I stepped up using a stir plate. I saved a small amount of slurry from this starter which I then later used to make the starter for the Dubbel.

 

[razz]

I don't think that the temp dropping a few degrees will stop the yeast from reabsorbing diacetyl, it may take a bit longer.
Leave it another week and see how it tastes.

 

[Nick JD]

You can try the diacetyl test to see whether it's coming from a subtle pedio infection or from the yeast precursor AAL.

How do you know if your beer contains an excessive amount of alpha acetolactate (AAL), thus necessitating a diacetyl rest to yield shelf-stable beer? The test is not only easy and accurate, but it requires only some glassware, hot water, and the very sophisticated aroma analyzer found in the middle of your face!

This test is based on the fact that heat will rapidly oxidize the relatively flavorless AAL into butter-like diacetyl. You will need two glasses with covers; aluminum foil works well in this role. You will also need a hot water bath big enough to hold one of the glasses. The water should be heated to 140-160 F.

Place a sample of your young beer in each glass. Cover and put one in the hot water bath while keeping the other at room temperature. Keep the beer in the water bath for 10-20 minutes.

Cool the hot beer to about the same temperature as the cool sample; a cold water bath can be used to good effect for this. Remove the covers and smell each sample. One of the following conditions will exist:

1. Neither beer smells buttery. This is good! It means that all of the AAL has already been converted to diacetyl and your beer is ready for packaging.

2. The heated sample smells buttery, but the cold one does not. This means that there is excessive AAL still floating around your beer, and you should age it at 60 F or so for a few days to allow diacetyl to form and then be metabolized by the yeast. Repeat the test to determine the proper time for packaging.

3. Both samples smell like butter. This can be a bad thing. It can be indicative of a pediococcus infection, in which case you should dump the batch and start over, or it can mean that your yeast is incapable of metabolizing diacetyl (see respiratory mutants, above).

It could also mean that your beer is still kind of young and you should try the test again after a few more days of warm aging. Hopefully the diacetyl will fade. Krusening with fresh yeast may also help, unless the problem is bacterial.

 

[JaseH]

Cheers, I'll give that test a shot.

 

[JaseH]

Well I tried the test but I think it was pretty much pointless as the room temperature sample already had noticeable diacetyl so I'm not sure what warming up the sample was going to do?

I'll leave it another week and see how its going, if no joy maybe I'll try krausening it as a last resort. I'm starting to think maybe a peddiococcus infection in my original starter is the problem?

 

[JaseH]

As a last ditch attempt to fix this before writing it off as an infection, I figure i will try krausening it - which I've read can work.

Will simply pitching a pack of US05 into it do the job or should I actually build a starter from something? I have some 1272 American Ale II in the fridge I could try.

Also should I rack it off the primary yeast cake before hand or ok to leave it?