Basement temps swing from 67-62. Is this a problem? Using US-05

I'm about to brew an ale and I was wonder if temp swings like that could be dangerous. And if so what could I do to cut down on the swing?

 

For us-05 you should be ok if you set up a swamp cooler to counter the higher part of that range.

 

It's best to keep the wort at a stable, constant temp. Small swings probably won't hurt, but larger ones could stress the yeast, possibly leading to off-flavours.

Note the words "could" & "possibly" there.



Also, I am not sure if 5 degrees is what one would consider a large swing. Hopefully others here more experienced than I can answer that one.

If you have some sort of insulated container (like a cooler, but IDK how big & what shape your FV is) to put it in, it would help even out & regulate the temperature so any outside fluctuations would be minimized.

 

So like this?

 

You could use that cooler, with some blue ice...without it and it may creep into the 70's. Once the main part of primary fermentation is over the wort will stop driving the temps higher then ambient and the 5 degree swing will not be a factor. Just make sure your main ferment is under the applicable temp.

 

I put my fermentor in a large bin filled part way with water. The water helps to stabilize the temperature, since it takes time for a swing in air temperature to warm or cool that large a volume of liquid. With that range, you should be fine.

The only problem with a cooler, without anything to cool down the fermenting beer, is that heat produced by the yeast will be trapped, leading to greater temperature increases during the most active phase of fermentation than if the fermentor were simply sitting in the open room.

 

So use the ice to drive down the temp inside the bigger cooler so that the wort temp stays in the range? Due to it being 5-10 degrees warmer because of the fermentation?

 

exactly

 

You will just need to change out your cold packs frequently. A water bath has the advantage of more stable temperatures, due to the increased volume of liquid, and the ability to use frozen bottles/cold packs to drop the temp a bit more if you want.

 

Yeah, sorry, I did forget to mention that you will need a little something to help keep it cool.

Maybe, I dunno... what about leaving the cooler open when it is the coolest and then closing it as soon as it starts to warm up? But that's the frugal way... a few small bottles of ice will work well.

 

Disadvantage - using lots more water; space might be a concern; and I was thinking that the volume of wort itself will also help stabilize against the temp-swings. 5-6 gallons will hold temps better than 1 or 2 gallon batches, and 10-G batches even more so.

Just some thoughts floating by in my mind...

 

I live in an old farm house with a well. Water is not a concern. I think im just gonna fill up a cooler with water and use ice packs. It seems like the best idea and it will work well.

Plus I'm doing a 3-gallon batch so the swamp cooler with water seems to be the best route.

 

With the water method should I assume the wort temp will be near the temp of the water surrounding it? Or is there a general rule to assume its a few degrees higher?

 

This is what I assume. I'm sure someone may chime in with a hair splitting theory or logic, but liquid to liquid - can't be too much different, mabe a degree or so...the more water you have on the outside volume the more stable it will be. Early in the fall - when I need to keep my wort cooler than ambient I'll fill my swamp cooler as much as I can ( 10-12 gal)...right now though, basement temps are in a good range so I just have 5 gallons in it to help temperature stability.

 

Yeah, if you partially submerge your fermenter it's a safe bet that it is pretty close to the the same temp as the water it's in.

Honestly, if you control the temps with a water bath the first three days using the cooler like you do in the pic for the rest of your primary fermentation will work really well. It's only those first few days that the fermentation has the energy to drive the temp up in any considerable way. After that it will be very close to ambient temps and by keeping it in a cooler it won't go through significant temp swings.

 

The temp swings are not that big. Think about it. To change the temp of a 5 gallon fermenter a temp swing of a few degrees for a few hours will not do squat. If your brew is at 65, a few hours at 62 or a few hours at 67 will barely change the temp of a five gallon fermenter.

Don't worry about it.