Lager fermentation temps

[Richard]

Hi All,

I brewed my first lager on Sunday last week. I used an AHS kit with some Fermentis lager yeast. The yeast packet says the ideal temps are between 45 and 55. I'm using a room in my basement for the fermentation, so I've been able to control the temp with an open window, but the weather is getting unseasonably warm, and may get up to 60 in the next few days. The batch has been bubbling merrily along in the mid to high 40s for over a week now, so I'm hoping that the warmer weather won't spoil things. Perhaps it will provide a "diacetyl rest"?

 

[Soulive]

Put it in a tub, with cold tap water, that has enough space for you to add frozen water bottles if needed...

 

[Richard]

I don't really have a tub that big, and I'm afraid that might let water in through the spigot (I'm using a Better Bottle). The temp at night will of course be lower, so I'm hoping that this slight fluctuation won't have a bad effect on the beer.

Hopefully temps will go back down to normal around here in a few days.

 

[Richard]

I guess I'm looking from some reassurance that my beer will handle the temp fluctuation. Any experienced lager brewers out there?

 

[Evan!]

Hmmm...let's see. A lot of people seem to experience long (2 weeks) lager fermentation times. Personally, I've done 4 lagers and every one of them was done within a week. I can't say for sure, but you might be far enough in the process that you're past the point at which esters would be created by higher temps. I say just let it go, and the worst that happens is you have half-steam-beer.

I say, you're pretty brave though. I wouldn't try lagering without a dedicated temp-controlled fridge/freezer.

 

[Iordz]

If the warmer temperatures come towards the end of fermentation you will be fine. It is important to control the temperatures during the first 48 hours, or until the yeast starts fermenting steadily. This will create a minimal ester profile with small diactyl production. It seems like your beer was cold for the begining of fermentation therefore the yeast would have laid the foundation for a clean lager.

 

[Richard]

Hmmm...let's see. A lot of people seem to experience long (2 weeks) lager fermentation times. Personally, I've done 4 lagers and every one of them was done within a week. I can't say for sure, but you might be far enough in the process that you're past the point at which esters would be created by higher temps. I say just let it go, and the worst that happens is you have half-steam-beer.

I say, you're pretty brave though. I wouldn't try lagering without a dedicated temp-controlled fridge/freezer.

Well, with temps outside being pretty cold I was able to keep the temp in my brewing room quite steady simply by adjusting the window opening. I wasn't counting on the weather getting this warm, but perhaps my basement will stay cool. I'll see when I get home tonight...

 

[Richard]

If the warmer temperatures come towards the end of fermentation you will be fine. It is important to control the temperatures during the first 48 hours, or until the yeast starts fermenting steadily. This will create a minimal ester profile with small diactyl production. It seems like your beer was cold for the begining of fermentation therefore the yeast would have laid the foundation for a clean lager.

It most likely started off the fermentation process in a cool state. The wort was a bit warmer than it should have been when I first pitched, but the fermentor had been sitting in the mid 40s for several hours before any activity kicked off. The weather was really cold at that stage, and I was able to keep things at about 45 for the next week.

 

[menschmaschine]

I think once the Krausen starts to fall, you'll probably be alright, but I've heard fruity things about dry lager yeasts in general. One suggestion to prolong your temps would be to close the window once the outside temp gets above your preferred fermentation temp. (Like during the day). Then open it again at night. This should keep a steadier temp if night is colder and day is hotter. (Unless, of course, you have something creating heat in your basement, like a furnace.)

 

[Yooper]

I stick my BB in a water bath all the time and I haven't had problems with the spigot leaking. I like the water bath in the cooler idea because it keeps your temperatures even if the ambient air temperature fluctuates. Maybe you could do it in a utlity sink. Or at least throw a thick blanket over your fermenter to insulate it- that will help alot.

 

[Richard]

I think once the Krausen starts to fall, you'll probably be alright, but I've heard fruity things about dry lager yeasts in general. One suggestion to prolong your temps would be to close the window once the outside temp gets above your preferred fermentation temp. (Like during the day). Then open it again at night. This should keep a steadier temp if night is colder and day is hotter. (Unless, of course, you have something creating heat in your basement, like a furnace.)

Yes, well, unfortunately I had to shell out several grand for a new boiler at the beginning of this winter, and it keeps things pretty warm. It isn't near the room I'm using for fermentation, but there are a couple of pipes that impart heat. My thermometer records the high and low temps, so I shall see...

 

[Richard]

I stick my BB in a water bath all the time and I haven't had problems with the spigot leaking. I like the water bath in the cooler idea because it keeps your temperatures even if the ambient air temperature fluctuates. Maybe you could do it in a utlity sink. Or at least throw a thick blanket over your fermenter to insulate it- that will help alot.

I like the blanket idea. Right now I just have a cardboard box. I'll put a blanket on it when I get home.

 

[TexLaw]

If you can get it in the tub, I like that idea best. At the very least, that will help minimize temperature swings. Covering it with a blanket might actually work against you, as fermentation creates heat.

And, like Yooper mentioned, don't worry about water coming in through the spigot. If nothing is coming out, nothing will get in.


TL

 

[Richard]

Thankfully, temps by the fermentor didn't go above 53 today. It's supposed to get colder as the week wears on, so that's good news.