Diacetyl rest can’t achieve proper temperature

[B33rL0v3r]

I recently brewed a German Pilsner with a large starter of WLP830. Everything is going swimmingly fermenting at 50F. When FG reached 1.016, I turned off my glycol and started to let temperature rise for a diacetyl rest…

Problem is temperature in my garage doesn’t get above 57F. I’m fermenting in a conical and don’t have a heat wrap or heater, so seems I’m SOL getting my temps higher.

I was going to d-rest for 3 days. Since I can’t get should I double my rest time? Will the yeast still clean up the diacetyl at 57F?

for the record, I heated a sample up and smelled the popcorn, so I know it’s there.

 

[marc1]

I recently brewed a German Pilsner with a large starter of WLP830. Everything is going swimmingly fermenting at 50F. When FG reached 1.016, I turned off my glycol and started to let temperature rise for a diacetyl rest…

Problem is temperature in my garage doesn’t get above 57F. I’m fermenting in a conical and don’t have a heat wrap or heater, so seems I’m SOL getting my temps higher.

I was going to d-rest for 3 days. Since I can’t get should I double my rest time? Will the yeast still clean up the diacetyl at 57F?

for the record, I heated a sample up and smelled the popcorn, so I know it’s there.

Ideally you want to raise temps for a diacetyl rest before you reach final gravity. If it's not actually at FG and there's still a few points to go, you could get a brew belt, and maybe cover it with a blanket or sleeping bag to hold in some heat.

https://clevelandbrewshop.com/collections/ferment/products/bbelt

 

[dmtaylor]

A diacetyl rest at 57 F will still work. I don't think the temperature is as critical as the time. Most people claim that a diacetyl rest of about 3 days is sufficient, then you can cold crash. I totally disagree. It's closer to 3 to 3.5 WEEKS in most cases, in my experience, and this would include any temperature up to and including room temperature. We're all so focused on temperatures, and always rush rush rush. Focus more on being patient and giving the process TIME to do what is needed, that's the key IMO.

 

[Jag75]

Get an electric space heater to help now , but line up a TCS for your conical. The following process has produced nice lagers w/o diacetyl.

Once fermentation is 75% done I ramp up the temp a few degrees a day. When It reaches high 60's I let it sit for 3 days. After 3 days I start lowering the temp a few degrees a day until it's in the 30's . After a few days in the 30's it's ready to keg.

 

[Dland]

Heating it up a bit will certainly speed things along, but agree it will work out at 57F, or even lower, if given enough time.

The more I've focused on making good lagers, the more I'm finding what dmtaylor posted. The standard ramp up/D rest for a few days around 65F/ramp down is sufficient to get rid of diacetyl, and make pretty good beer. However giving the yeast more time before crashing to really "clean things up", even a few of weeks in some cases, makes for the best possible result.

 

[Steveruch]

First question you should ask is, "does it actually need a d-rest?"

 

[marc1]

First question you should ask is, "does it actually need a d-rest?"

for the record, I heated a sample up and smelled the popcorn, so I know it’s there.

Probably

 

[B33rL0v3r]

Thanks everyone! I’m going to let it sit on the yeast for another week or two and then I’ll take another sample to smell. If it’s good I’ll start the cold crash process. Really appreciate the insight.

 

[Bobby_M]

You really need to get some kind of heat pad for that setup. The ability to warm is just as important as the cooling.

 

[Dland]

^^^ A Fermwrap and a Inkbird 308 is works well for this. After initial investment, simple heat control, and you can use the 308 later for cooling when you get that together.

 

[hottpeper13]

When I started brewing lagers I thought in the beginning there were caves that were not temp controlled. So I did one at 50-55* (34/70 dry version of 830) for 3 weeks in primary, Kegged, and lagered at 33* for 4 weeks, clean and crisp.

 

[VikeMan]

High temperature diacetyl rests simply accelerate the production and cleanup of diacetyl. Exactly the same things happen at normal lager fermentation temperatures, just more slowly.

 

[SMD]

I recently brewed a Helles Lager in my basement at about 56 degrees and once I was ready to move to the D-Rest I brought it upstairs, and put it in a room with a space heater. That wasn't quite enough to get it to 68-70 for me, so I threw an electric blanket around it on low, which I cycled on and off for about an hour at a time, which got me to the 68-70 range and held it for 4 days. Electric blanket ftw, assuming you can monitor your temp. I have an Ispindel in mine.

 

[hottpeper13]

The key to clean and conditioned beers is a pipeline. I like to lager at 33* for at least 4 weeks so i need to stay quite a few beers ahead.

 

[odie]

High temperature diacetyl rests simply accelerate the production and cleanup of diacetyl. Exactly the same things happen at normal lager fermentation temperatures, just more slowly.

hence the term "lagering"? don't lagers traditionally take time to "finish" even after all fermentation is done?

Sounds like pushing a wet noodle by raising the temps to speed it up. I see the value in commercial production, time=money.

But in home brewing, unless you are out of beer and thirsty...well there is the NEED for multiple batches and taps at any given moment...

 

[VikeMan]

hence the term "lagering"? don't lagers traditionally take time to "finish" even after all fermentation is done?

Yeah, but I really suspect there wasn't a whole lot of diacetyl reduction happening at true lagering temps (as opposed to lager fermentation temps). In the old days, I suspect brewers relied (consciously or not) on the s-l-o-w ramp down from fermentation temps to storage temps to take care of any remaining diacetyl.

So, what happens after lagering temps are reached? Mostly "physical" things like yeast flocculation and the formation of protein/polyphenol aggregates that then drop out of suspension.

 

[Dland]

Sounds like pushing a wet noodle by raising the temps to speed it up. I see the value in commercial production, time=money.

But in home brewing, unless you are out of beer and thirsty...well there is the NEED for multiple batches and taps at any given moment...

While I agree there is no need to push things, if fermentation temp was on low side, ie 52F or lower, time in high to mid 50s a few weeks before crash and lager temp may be needed to deal with diacetyl, even if full ramp up to 65F is not employed. Though admittedly I have never tried leaving beer at 50F for several months, maybe that would finish it off, not sure.

Some of us are into brewing enough to have gear and will to run a long "pipe line", myself included. However, there are many home brewers who do not have a the quantity of kegs and temp controlled storage space to keep tied up for a few months to make good lager. For them, forcing the temp with ramp up & a week at 65F may be the only practical way to condition their lagers.

 

[VikeMan]

Though admittedly I have never tried leaving beer at 50F for several months, maybe that would finish it off, not sure.

It will finish at 50F. But if that takes months, there's a process problem somewhere.

 

[Dland]

It will finish at 50F. But if that takes months, there's a process problem somewhere.

How long do you think it would take, say at 48-50F? I know I've tasted diacetyl in beer after two weeks, have never left in PV for longer though.

Usually I ferment in conical until gravity is .006-8 above expected finish, then I usually go three or four more weeks in kegs with temp control before crashing. Sometimes I run low on temp control devices when I'm on a roll (I only have 6) then I just let lagers condition in cool room, they work out just as well as controlled ones, but take longer depending on temp.

I guess I'm using kegs as secondary, but not really my intention. I'm quite into spunding for carbonation, which alters my practices from what many do to be sure.

 

[odie]

I've never considered or thought much about this diacetyl rest thing or lagering in general. Until recently, most of my stuff has been ales. The occasional lager i've just done fermentation at traditional lager temps and then set aside for a while in a keg at a colder temp until I get around to tapping it. So they have always had a chance to sit a while first.

Only recently have I been where I may tap a lager fairly quickly after kegging. So taking a much more interest in this "rest thing"

 

[Jag75]

Diacetyl is never an issue until it is .

 

[VikeMan]

How long do you think it would take, say at 48-50F? I know I've tasted diacetyl in beer after two weeks, have never left in PV for longer though.

IME, 3-4 weeks max (but usually less), unless there is a problem with nutrients or something like that. But there's nothing wrong with an elevated temp rest if time is important.

 

[Dland]

Some brews I've had were two weeks in PV at low temp, and up to three weeks in kegs spunding, D rest, ect.. Reason I waited that long before crash is because pressure in kegs was still building, even though slowly at the end. Usually it is more like two weeks, but just had a couple in a row that took three to stop building pressure. Running cone to cone, continuous, so the yeast is plentiful and happy.

Correct me if I'm wrong, but I figure since pressure is still building then yeast is is still working it out, temp constant, of course.

Anyway, have been very happy with the lagers I've been making lately, guess that is what matters. Patience certainly is part of the process.

IME, 3-4 weeks max (but usually less), unless there is a problem with nutrients or something like that. But there's nothing wrong with an elevated temp rest if time is important.

 

[VikeMan]

Correct me if I'm wrong, but I figure since pressure is still building then yeast is is still working it out, temp constant, of course.

I'd say that's a safe bet.

 

[Bobby_M]

Diacetyl is never an issue until it is .

There's way too much time and effort invested into lagers to have it fail as a diacetyl bomb in the end. One of the reasons I will never rely on time at low temps is that it crashes the yeast out which are required to do that diacetyl cleanup. MAYBE enough yeast will make it but why chance it? The only detriment to a warm rest is if you have bad sanitizing skills have a bacterial contamination that would accelerate at warmer temps.

 

[Jag75]

There's way too much time and effort invested into lagers to have it fail as a diacetyl bomb in the end. One of the reasons I will never rely on time at low temps is that it crashes the yeast out which are required to do that diacetyl cleanup. MAYBE enough yeast will make it but why chance it? The only detriment to a warm rest is if you have bad sanitizing skills have a bacterial contamination that would accelerate at warmer temps.

Agreed