I pitched lager yeast at high temps. Did I ruin my beers?

[tlacualchiuhqui]

Yesterday, I finally found time to brew a couple of beers I'd wanted to make for a long time: two classic light lagers, one brewed with rice and the other with corn.

This was my first time brewing two beers on the same day, and I pulled it off, in just eight hours or so... I know light lager is an unforgiving style, so I was meticulous about sanitation, mash and sparge temperatures, and gravity. Then, I made two big mistakes.

First, I was rushing to finish the first beer and move on to the second, so I only chilled it to about ninety degrees before transferring it to a carboy, and pitched after it had been sitting for about an hour. (I'm used to brewing in cooler temperatures.) Then, rushing to finish the project, I did the same with the second. Our air conditioning isn't working, so the house is about eighty-five degrees, and I realized a couple of hours later, when I decided to check the wort temperature with a sanitzed thermometer, that neither had cooled much below that.

That was moment of panic number one. Then, number two, I woke up this morning to find that my temperature controller wasn't working properly, and the lagers had been sitting in my kegerator at temperatures in the sixties and seventies all night. That's not the end of the world, I guess, but it can't help, when I was aiming for fifty-five. They were fermenting vigorously.

I finally have them down to fifty-five degrees, less than twenty-four hours later, but they've been through a lot in the past day. Will they survive? Will they be wrecked by fusels and esters? I will not make this mistake again. I know the only way to find out is to wait and see, but I'm not sure I want these beers taking up all the space in the kegerator for the next month or longer if there's a good chance they aren't going to be good.

TL;DR: I pitched my lager yeast into eighty-to-ninety-degree wort, and then the beer sat overnight at temperatures in the sixties and seventies. I have it down to fifty-five now, but I think I might be screwed, and I'm trying to decide what to do next.

 

[mongoose33]

I don't think it's going to help you much; you might well have killed off most of the yeast. If by now, almost 24 hours later, you have no indication of activity, it's worth repitching at the lower temp, with the yeast acclimated to that temp before you pitch.

If you have little or no activity, you're not going to be producing much in the way of off-flavors or fusel alcohols or anything like that.

Get the temps down, repitch would be my suggestion.

BTW: you're not the first to do this, so don't feel like you're the Lone Ranger.

 

[z-bob]

Repitch and it's probably fine. If you don't have any more lager yeast, use an ale yeast or K1V-1116 wine yeast; it won't be lager but it will be beer.

 

[azmark]

depends on the yeast on what off flavors you might get.

You don't have to repitch. As you said the lager yeast was going like crazy. 90 degrees wont kill them off, they'll just throw off flavors.

 

[z-bob]

I missed the part where they were fermenting vigorously; no need to repitch. Let it go and see what you get.

 

[Northern_Brewer]

I only chilled it to about ninety degrees before transferring it to a carboy, and pitched after it had been sitting for about an hour. (I'm used to brewing in cooler temperatures.) Then, rushing to finish the project, I did the same with the second. Our air conditioning isn't working, so the house is about eighty-five degrees, and I realized a couple of hours later, when I decided to check the wort temperature with a sanitzed thermometer, that neither had cooled much below that.

Typically 37C (98.6F) is quoted as being fatal to lager yeast, but there is quite a bit of variation between strains, depending on how much ale DNA they have among other things. But the fact that you have activity is proof that at least some has survived. But in general yeast are far more temperature tolerant than people think - we only ferment low to avoid off-flavours rather than because it's the best temperature for yeast growth (ale yeast are happiest from a growth point of view at ~90F). Think about it, in the wild they're hanging round grapevines etc in Mediterranean climates where temperatures in the 90'sF are quite common.

Will they survive? Will they be wrecked by fusels and esters? I will not make this mistake again. I know the only way to find out is to wait and see, but I'm not sure I want these beers taking up all the space in the kegerator for the next month or longer if there's a good chance they aren't going to be good.

TL;DR: I pitched my lager yeast into eighty-to-ninety-degree wort, and then the beer sat overnight at temperatures in the sixties and seventies. I have it down to fifty-five now, but I think I might be screwed, and I'm trying to decide what to do next.

The relationship between temperature and off-flavours is very specific to each strain of yeast. If you look at the warm-fermented lager thread, you'll see that they are making lagers with very little off-flavours from certain strains like Mangrove Jack M54 Californian even at normal ale temperatures of ~70F, whereas other strains may be less forgiving.

 

[tlacualchiuhqui]

One-week update: I tasted both beers today. I wouldn't typically disturb them a week into fermentation, but I had to know what was going on. And... they're fine. For now. I'm not getting my hopes up, yet, but they taste like light lagers. (The one brewed with corn is shaping up to be a dead ringer for Yuengling, not Miller High Life, as I expected, but that's fine, too, and the one brewed with rice is about as close to Bud as I ever expected to get.) They're pretty clean, and that's pre-lagering. Maybe I got lucky.

 

[couchsending]

What yeast did you use?

 

[tlacualchiuhqui]

Bohemian Lager and Czech Pils from Wyeast. (I would’ve used American Lager for both, but my local homebrew shop only had those, and only one of each.)

 

[yourlastchance89]

I brewed a Belgian Tripel a few weeks back at the climax of summer and pitched Wyeast 3655 Belgian Schedle (ale yeast). I use an SS Chronical hooked up to an SS Brewtech glycol chiller. A fuse tripped at some time and my beer rose to 92°F within 24 hours of pitching. It was going crazy. I thought it was ruined. Tasted it last week before cold crashing and the only thing that stood out was a slight banana ester. RDWHAHB it'll buff out.

 

[seatazzz]

Hie thee to the Warm Fermented Lager thread. We do this all the time. I pitched 2nd gen 34/70 slurry on one of mine last weekend when it was at 85, and I'm drinking it now. No esters, no off flavors, and it flocced out like the beast it is. Granted, there's a bunch of Mosaic hops in it, but not enough to hide any mistakes that may have been made by pitching too warm. In my limited experience, most lager yeasts are more forgiving than their ale cousins.