7

NEVER use bubbling as a measure of anything important. You MUST take actual gravity readings to know where your fermentation is. As a general rule, you should do a diacytl rest when you are about 70-80% done with fermentation. So for a "normal" strength lager (1.050-1.060 OG) I'll start the diacytl rest when the beer hits about the 1.020-1.022 range (...


6

The warmer the fermentation (to a reasonable point) the more active the yeast is and the less diacetyl you'll get. To do a diacetyl rest for an ale, you just leave it on the yeast longer. It's not the temp that matters for a d rest. You raise the temp for lagers in order to make the yeast more active, but the actual temp (again, within reason) doesn't ...


5

As a long-time practitioner of this method, I'd recommend waiting longer than this article suggests. For me, the real benefit of the technique is an accelerated reduction of diacetyl at the end of fermentation, since by the time esters have maxed out (more on that below) pretty much all other potential off-flavors (higher alcohols, acetaldehyde, sulfur ...


5

You're right on the common combination of pedio and brett due to diacetyl production. But pedio doesn't start working for 2-4 months, and has a time-frame of 4-9+ months. So you have plenty of time to source brett to add to help with diacetyl production from the pedio. I'm honestly not sure if a traditional lager-style diacetyl rest (probably with newly-...


4

Most bad esters are made during growth phase and early fermentation, it's only at the end of primary fermentation that you do your diacetyl rest, after the risks of undesirable esters has past.


4

Bottom cropping yeasts are easier to rouse out of dormancy with higher temps than top cropping yeasts. I'd say that, even now, warming the fermenter up to 58 for the diacetyl rest would be totally appropriate and doable. I don't know that the time component is really important, unless it'd been so long that all the yeast was dead, and I don't think that's ...


3

Given their additional experiments of testing lagers fermented entirely at warmer temperatures, it would seem the answer is because the lager yeasts being used simply do not produce estery flavors or other off flavors at temperatures suitable for non-lager yeasts (60s and 70s). It would seem the lager yeast is what makes the difference between a lager and ...


3

Give your lager a nice long fermentation (say 4 weeks) with plenty of healthy yeast and it's unlikely you'll need a diacetyl rest. I typically take a gravity reading after 4 weeks and taste the sample. If there is diacetyl, I do the rest at that point. If I don't taste it, it doesn't need the rest. BTW, I don't think the yeast will necessarily be dormant....


3

I would do it later rather than earlier. By raising the temperature early, you risk introducing esters, fusels and sulphur compounds into the beer, which can't be cleaned up easily. Traditionally the diacetyl rest is done after primary, not during it. (see reference below.) So you should be fine just leaving the beer. When you get home from your trip, take ...


2

You can certainly pitch the Brett later. As mentioned the Brett will help with diacetyl, but it also helps with the ropey dextrinous 'gunk' that Pedi starts to throw in there. Without Brett that stuff doesn't clear out very easily. You need Brett to break that stuff down.


2

I'm not speaking from experience here, since I don't brew sours, but the yeast should reabsorb the diacetyl, just as it does in a regular ferment. The yeast will convert diacetyl into acetoin then 2,3-butanediol, which has much higher taste threshold than diacetyl. Both conversions provide energy, and so help sustain the yeast when other energy sources are ...


2

You may have picked the wrong yeast. I read somewhere I think it was from Wyeast, that all yeasts produce Diacetyl, but some yeasts are better than others at cleaning it up. So whenever Wyeast recommends a 'Diacetyl rest' for a strain, you should not use it to clean up Diacetyl. Instead I would pick a non English yeast that does not require a D-rest, which ...


2

He mentions it in the linked article: A few things we’ve learned over the last couple centuries of brewing is that yeast generally works slower at cooler temperatures and faster at warmer temperatures, most esters and phenolics are produced during the growth phase of fermentation, which in my experience lasts about 4-5 days for lager strains, and beer ...


2

At the beginning of the fermentation the yeast have access to some oxygen and/or stores of the metabolites made with oxygen. This allows them to replicate a few times, so naturally that's what they do. A byproduct of this is ester production, and other stuff (acetaldehyde, diacetyl, maybe some sulfury compounds, etc) that we usually don't like in our beer. ...


2

The warmer temperature should not make this problem worse. I'd let it sit for up to 48 hours and taste it again. I wouldn't bottle yet. Bottling (and conditioning in general) helps many beers but you'll waste 12 ounces at a time just to taste if you bottle it now.


1

It's simply because esters are produced only during growth phase. Once yeast has consumed the oxygen this triggers the end of growth and into feeding phase. Seeing that the SG has reached 50% of TG is confirmation growth is done and feeding his well underway. So it's ok at this point to increase their metabolism with temperature. But not too warm or then ...


1

My co author, Drew Beechum, is pretty much recognized as the master of saison. In our book "Experimental Homebrewing" he writes about 565 and how temprementl it can be. For one thing, you need to raise the temp into the 80s after the first couple weeks in order to get the yeast to finish. That will clean up a lot of the diacxetyl. Most surprisingly, it's ...


1

As long as your yeast is healthy and abundant and you're not cold-crashing the beer as soon as fermentation tails off, you'll be fine. I've fermented with a number of Saison and Belgian strains (though I can't remember which off the top of my head) and I've never had any problems with diacetyl. Also, basically any strain that's known to produce diacetyl in ...


1

Being that it's a sour and you pitched bacteria, it's entirely possible that the diacetyl is a result of your purposeful "infection". I don't think there are any guarantees, but I do think it's possible that it will be at least somewhat reduced by the yeast.


1

You may not need a d rest at all, so in that case you'd be OK. I only do a d rest when I actually taste diacetyl in the beer and that doesn't happen often. The purpose of a d rest is to make the yeast more active so they'll consume dicaetyl. Obviously, that would work better in primary where there's more yeast, but there should still be enough yeast in ...


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