Help me design a diacetyl reduction with Brett experiment

Discussion in 'Homebrewing' started by Naugled, Oct 24, 2013.

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  1. Naugled

    Naugled Pooh-Bah (1,944) Sep 25, 2007 New York
    Pooh-Bah

    I have 9 bottles of beer that I've set aside that have high levels Diacetyl which I believe was produced by ped. I would like to perform an experiment to test if Brett can reduce the levels of diacetyl in these beers. This won't be exact science since my only method of detecting the reductions will be by a panel of judges. But qualitative data can be useful as well.

    I'm looking for input/advice on how to set up such an experiment. Some variables I need advice on are 1. Amount of brett to add to each bottle? 2. How long to age before sampling? 3. What temperature should they be aged at? 4. Should wort/sugar be added to bottle as well? 5. Any other ideas?

    Here's what I'm thinking for simplicity and limited number of bottles.
    Age all bottles at one temperature T
    Bottle # Parameters
    1 Control for tasting session 1
    2 Control for tasting session 2
    3 X ml Brett, T1 age
    4 Y ml Brett, T1 age
    5 X ml Brett, T2 age
    6 Y ml Brett, T2 age
    7,8,9 extra? or other parameters?

    Also, if anyone can point me to any analysis done on this subject I'd appreciate it. There are hundreds of threads out there that talk about this reduction, but I have yet to find one that references any source of analysis. I don't doubt that it may be true to some extent, but I'm curious as to why there seems to be no quantitative data to back it up.
     
    #1 Naugled, Oct 24, 2013
  2. jbakajust1

    jbakajust1 Pooh-Bah (2,552) Aug 25, 2009 Oregon
    Pooh-Bah

    My thoughts are do 3 sessions, 3 beers each. 3 beers left alone. 3 beers dosed with stable, old Brett (maybe an unsmacked WY pack that is a couple months old). 3 beers dosed with same Brett f/ an active starter. Keep them all at around 68℉ and watch for pellicles to form in the bottles. Taste a set at 6 weeks, then at 3 months, then either 6 months or a year (depending on how the other tests turn out).

    This should give you some good info like how long it takes, will adding dregs from an old bottle of beer clean it up, does getting a starter going and "krausening" with Brett work, etc.
     
    #2 jbakajust1, Oct 24, 2013
  3. inchrisin

    inchrisin Pooh-Bah (2,013) Sep 25, 2008 Indiana
    Pooh-Bah

    I really like this idea.

    1. I think this will be overkill for a 12 oz bottle. I'm thinking 1/2 mils just so you can get a feel for what this would do for a 5 gal batch.

    2. I'd take the amount of time you'd be willing to wait for a 5 gal batch to shape up from having too much diacetyl 4 months?

    3. 65-70F should do the trick.

    4. I think this will be tricky because you don't know how far the brett will drop your FG. I'd be a little concerned about bottle bombs. The bottles are already carbed, right?
     
    #3 inchrisin, Oct 25, 2013
  4. Naugled

    Naugled Pooh-Bah (1,944) Sep 25, 2007 New York
    Pooh-Bah

    jbakajust1: I might be able to do something like you said, I have a couple of Brett beers going now (first ones). I was planning on inoculating with fresh Brett for the experiment, but I can pull from the beers I got going too. I was thinking the 6 wks and 3 months intervals as well. Ideally I'd like to see it work sooner than later, so I think the 6 wk tasting could be telling.

    inchrisin: I was thinking 1/2 ml range as well. I agree probably more than needed, but these samples have high levels of diacetyl so I thought about going high on the brett as well. I am very worried about bombs too. These samples I have are old ales, which have quite a bit of residual sweetness which should give the Brett plenty to work with. I'm thinking of putting air locks on the bottles to avoid pressure build up.

    New question: Brett Brux or Lambicus? I'm leaning toward Brux..
     
    #4 Naugled, Oct 25, 2013
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