Swamp Cooler Question

I am currently fermenting ales in my basement with an ambient temperature in the low 70's. I have been using a swamp cooler with the wet t-shirt and frozen water bottles. The water temperature fluctuates between 53F - 62F, depending on when the bottles are swapped out. Is there any point where I should stop swapping the bottles and let the temperature rise to ambient? Thanks.

53 degrees is really low for an ale. Depending on what kind of ale yeast you're using, 60 degrees is about as low as you want to go. For instance, the yeast I'm using doesn't like anything colder than about 65 degrees.

I've had my primary in a swamp cooler for a couple weeks. When the ambient was in the 80's, I used the frozen bottles of water and it kept the primary around 66 degrees. The past week has been much cooler, like in the 70's, so I stopped putting the frozen water bottles, and the primary temp has been around 64 degrees.

I'd say you should stop using the bottles and let it stabilize to around 64-66 (again, depending on the yeast. You should look p what that yeast likes).

onipar said:

53 degrees is really low for an ale. Depending on what kind of ale yeast you're using, 60 degrees is about as low as you want to go. For instance, the yeast I'm using doesn't like anything colder than about 65 degrees.

I've had my primary in a swamp cooler for a couple weeks. When the ambient was in the 80's, I used the frozen bottles of water and it kept the primary around 66 degrees. The past week has been much cooler, like in the 70's, so I stopped putting the frozen water bottles, and the primary temp has been around 64 degrees.

I'd say you should stop using the bottles and let it stabilize to around 64-66 (again, depending on the yeast. You should look p what that yeast likes).

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The swamp water gets as low as 53F, but I doubt that the wort is that low, especially during fermentation. Also, the 53F is low end, it doesn't last. I was wondering if it's still necessary to maintain low temps even after fermentation is complete. I usually go 4 weeks in primary.

PIGMAN said:

The swamp water gets as low as 53F, but I doubt that the wort is that low, especially during fermentation. Also, the 53F is low end, it doesn't last. I was wondering if it's still necessary to maintain low temps even after fermentation is complete. I usually go 4 weeks in primary.

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Oh, oh, that's the *water* temp? Sorry, I missed that. You don't have one of those adhesive thermometers on your primary bucket/carboy?

I don't think it's as important to keep the lower temperature once fermentation is complete. I think I've read that some people like to warm it up a little near the end to make sure the yeast stay active ferment out all the sugar, but I just keep mine at a steady temp (mid-sixties for the bucket temp) until I'm ready to bottle.

Temperature control isn't necessarily about keeping the fermenting beer cold, it's more for maintaining the temperature. If your basement maintains an ambient temperature of 70 with very little fluctuation then you're better off leaving it in a dark area to ferment without the swamp cooler.

jerryalan said:

Temperature control isn't necessarily about keeping the fermenting beer cold, it's more for maintaining the temperature. If your basement maintains an ambient temperature of 70 with very little fluctuation then you're better off leaving it in a dark area to ferment without the swamp cooler.

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That's if you're brewing ales. Lagers will require colder temps.

jerryalan said:

Temperature control isn't necessarily about keeping the fermenting beer cold, it's more for maintaining the temperature. If your basement maintains an ambient temperature of 70 with very little fluctuation then you're better off leaving it in a dark area to ferment without the swamp cooler.

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Problem is that it's more like low 70's, which from what I understand is inviting off-flavors.

PIGMAN said:

Problem is that it's more like low 70's, which from what I understand is inviting off-flavors.

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The thing is, you're using ambient temps and water temps. You really should use an adhesive thermometer strip to determine the wort temp. When they say that fermenting your wort at 70 degrees can cause off flavors, they mean the wort temperature, not the ambient room temp.

It's hard to know what the wort temp is based on the ambient and swamp water temps. You can make an educated guess, but it's hard to tell.

onipar said:

The thing is, you're using ambient temps and water temps. You really should use an adhesive thermometer strip to determine the wort temp. When they say that fermenting your wort at 70 degrees can cause off flavors, they mean the wort temperature, not the ambient room temp.

It's hard to know what the wort temp is based on the ambient and swamp water temps. You can make an educated guess, but it's hard to tell.

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Good point, thanks. Let's assume for argument's sake that the wort is 66F - 68F due to the swamp cooler. Should I leave it there for the full 4 weeks in primary, or at some point do I let it rise to the low 70's
I will check the actual wort temp this evening.

PIGMAN said:

Good point, thanks. Let's assume for argument's sake that the wort is 66F - 68F due to the swamp cooler. Should I leave it there for the full 4 weeks in primary, or at some point do I let it rise to the low 70's
I will check the actual wort temp this evening.

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jerryalan's advice is sound. Supposedly off flavors may also occur if there are too many sudden fluctuations in the wort temperature. (The swamp cooler should protect against drastic changes in temperature). I'd just leave it in the 66-68 degree area.

There *are* benefits to cold crashing and diacetyl rest, but I know very little about those topics, and I *think* that's more with lagering. Maybe someone with a bit more experience will pop in soon, but generally speaking leaving it at a steady temp without fluctuations is best.

PIGMAN said:

Good point, thanks. Let's assume for argument's sake that the wort is 66F - 68F due to the swamp cooler. Should I leave it there for the full 4 weeks in primary, or at some point do I let it rise to the low 70's
I will check the actual wort temp this evening.

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Lately I've been raising the temp about seven to ten degrees when the krausen falls. I've seen lower FG numbers as a result. In your situation you'd have to find a way to maintain a steady temp of around 65F and then let the beer warm up to your ambient temp of 70F. You could continue using the swamp cooler with a t-shirt or towel draped over the fermenter (with the ends in the water) and have a fan blowing on it to increase evaporation. Skip the ice though. When the krausen falls (usually a couple of days after visible fermentation begins) remove the t-shirt and fan and allow the beer to raise to your ambient temp. Then let the fermentation complete for however long you usually go for.

Like onipar said: get a stick-on thermometer. Be sure to stick it on horizontally and not vertically though.