Swamp Cooling Temperature + Fermenter Temp?

[LuisCheco]

Hi, I have been reading some post about how to keep the fermenter in a swamp cooler and how to keep it cold.

But my question is, what would be the difference in temperature between the water in my swamp cooler and the temperature inside my fermenter??

Example, if the water in my swamp cooler is around 70°F, what would be the temperature inside of my fermenter??

 

[specharka]

Hi, I have been reading some post about how to keep the fermenter in a swamp cooler and how to keep it cold.

But my question is, what would be the difference in temperature between the water in my swamp cooler and the temperature inside my fermenter??

Example, if the water in my swamp cooler is around 70°F, what would be the temperature inside of my fermenter??

Swamp coolers work by evaporative cooling, not from transmission to the surrounding water. With the additional surface area associated with a terry cloth towel and a fan, you're probably looking at a dT of 3-5°F at most (from ambient). Without anything other than water surrounding it, your beer will be the same temperature as the water.

Not good for lagering. Not good for controlled fermentations.

 

[LuisCheco]

Swamp coolers work by evaporative cooling, not from transmission to the surrounding water. With the additional surface area associated with a terry cloth towel and a fan, you're probably looking at a dT of 3-5°F at most (from ambient). Without anything other than water surrounding it, your beer will be the same temperature as the water.

Not good for lagering. Not good for controlled fermentations.

Well...I'm keeping my fermenter submerged midway in water. In this case, what would be the difference between my wort temp inside the fermenter and the water temp?

 

[specharka]

Well...I'm keeping my fermenter submerged midway in water. In this case, what would be the difference between my wort temp inside the fermenter and the water temp?

0

In fact it might even be higher if it's rejecting heat to the water.

 

[rodwha]

I kept m fermenters submerged in a tub of water and rotated frozen water bottles for about 2 years. Initially I only monitored the water temp thinking it was the same. When I finally attached fermometers I found they were about 5* warmer then the water, which I kept in the mid 60's.

 

[LuisCheco]

I kept m fermenters submerged in a tub of water and rotated frozen water bottles for about 2 years. Initially I only monitored the water temp thinking it was the same. When I finally attached fermometers I found they were about 5* warmer then the water, which I kept in the mid 60's.

My fermometer it's around 70-72°F... sooo.. it means my wort is around 65-67°F??

 

[specharka]

My fermometer it's around 70-72°F... sooo.. it means my wort is around 65-67°F??

Uhhh....no.

Your wort is rejecting heat to the water. Therefore, it is at a higher temperature than the water.

 

[LuisCheco]

Uhhh....no.

Your wort is rejecting heat to the water. Therefore, it is at a higher temperature than the water.

Sorry, I didn't explain very well my situation. I have a 6gal carboy with a 5gal Brown Nut Ale batch. Everything went well... I think. It is my first batch.

This batch have 1 week and 3 days fermenting. Which means active fermentation is done. So... my wort temp is almost similar to the water in the swamp cooler or it's still higher?

 

[rodwha]

It may stil be a bit warmer, but after the first 3 days or so it isn't crucial anymore. I pull mine out of the 64* fermentation chamber after a week to allow it to warm up. Some do this after three days.

What I meant was that my wort was about 5* warmer than the water.

 

[LuisCheco]

It may stil be a bit warmer, but after the first 3 days or so it isn't crucial anymore. I pull mine out of the 64* fermentation chamber after a week to allow it to warm up. Some do this after three days.

What I meant was that my wort was about 5* warmer than the water.

At what temp you let it warm?

 

[rodwha]

Typically about 75* when the a/c is on while hot. Now it's about 73* and will be about that when I run the heat.

 

[pricelessbrewing]

Not sure I agree with the info offered here. Water is a pretty good thermal conductor, as long as adequate surface area is in contact between the water and the fermenting beer then the temp difference should be minimal.

 

[rodwha]

Within reason I'd think the temp wasn't too big of a deal. Some keep their house around 80* in the summer and I'd guess that was fine too, though I cannot say for sure at what point it may (or may not) become an issue. Ultimately it's the active fermentation temp that matters most.

 

[rodwha]

Not sure I agree with the info offered here. Water is a pretty good thermal conductor, as long as adequate surface area is in contact between the water and the fermenting beer then the temp difference should be minimal.

I'm curious what you disagree with.

 

[MaxStout]

Not sure I agree with the info offered here. Water is a pretty good thermal conductor, as long as adequate surface area is in contact between the water and the fermenting beer then the temp difference should be minimal.

The water also acts as thermal mass. It limits fermenter temp swings that might otherwise occur due to day/night temp changes in the house.

You can also chill the water by adding ice packs or frozen, water-filled pop bottles, and change them out a couple times a day. I can drop the fermenter temp by 4 or 5 degrees this way.

 

[Calder]

Swamp coolers work by evaporative cooling, not from transmission to the surrounding water. With the additional surface area associated with a terry cloth towel and a fan, you're probably looking at a dT of 3-5°F at most (from ambient). Without anything other than water surrounding it, your beer will be the same temperature as the water.

Sure it works by transmission of heat to the surrounding water. The evaporative effect is just a method to cool the water.

Well...I'm keeping my fermenter submerged midway in water. In this case, what would be the difference between my wort temp inside the fermenter and the water temp?

I do this too. I probably have a 6 gallon fermenter in 10 or more gallons of water. My measurements on many batches show the water is extremely efficient at removing heat and keeps the beer within a degree or maybe two of the water. It also reduces temperature swings, both up and down as room temp changes.

 

[specharka]

Sure it works by transmission of heat to the surrounding water. The evaporative effect is just a method to cool the water.



I do this too. I probably have a 6 gallon fermenter in 10 or more gallons of water. My measurements on many batches show the water is extremely efficient at removing heat and keeps the beer within a degree or maybe two of the water. It also reduces temperature swings, both up and down as room temp changes.

I think we are talking about apples and potatoes here...

OP said he had a fermenter in contact with water midway up the bucket, at 70F. That just moderates the fermenter temperature to water temperatures. Sorry, that's not a swamp cooler.

A swamp cooler uses a water reservoir connected to a towel and/or a source of fresh air. The towel has a larger surface area than the reservoir and acts as a heat sink for the fermenter. At equilibrium conditions, the towel will be at the same temperature as the ambient dew point temperature, and LOWER than the reservoir temperature. Ergo, the heat rejection pathway goes through the fermenter, and not the reservoir.

So no, it doesn't work that way.

 

[rodwha]

Erroneous as it may be I think many use the term. It's what I thought it was called too, and I suspect it's what the OP is using.

The thermal mass and the fact I rotated frozen water bottles three times a day certainly kept it in check and I had no issues with fusel alcohol development despite the house being at 75*.

 

[LuisCheco]

I think we are talking about apples and potatoes here...

OP said he had a fermenter in contact with water midway up the bucket, at 70F. That just moderates the fermenter temperature to water temperatures. Sorry, that's not a swamp cooler.

A swamp cooler uses a water reservoir connected to a towel and/or a source of fresh air. The towel has a larger surface area than the reservoir and acts as a heat sink for the fermenter. At equilibrium conditions, the towel will be at the same temperature as the ambient dew point temperature, and LOWER than the reservoir temperature. Ergo, the heat rejection pathway goes through the fermenter, and not the reservoir.

So no, it doesn't work that way.

Thank you, for taking the thread on track and correcting me. And a correction, I'm using a carboy.

Ok, so I'm not doing a swamp cooler.

But my question is, having my carboy submerged midway with water will keep my wort temp in the carboy/fermenter close to the water temp?

This batch have already 1 week and 3 days fermenting.

 

[rodwha]

Close. And it could be that the temp split I saw was off as I'm not sure if my thermometers were spot on and the fermometers are vague.

If your water temp was 70* I'd venture to guess that your wort/beer temp was that to 6* warmer. Maybe even a little higher as I submerged about 4 gals out of 5.5-6 gals or about 2/3 of it.

 

[pricelessbrewing]

I'm curious what you disagree with.

The info that the water surrounding a fermenting beer will be 5 degrees warmer than the beer because water doesn't loss thermal energy passively (also false).

The water also acts as thermal mass. It limits fermenter temp swings that might otherwise occur due to day/night temp changes in the house.

You can also chill the water by adding ice packs or frozen, water-filled pop bottles, and change them out a couple times a day. I can drop the fermenter temp by 4 or 5 degrees this way.

This is it exactly. There are three benefits of a swamp cooler, one you get additional thermal mass which lowers temp swings and increases thermal conductivity so more heat flows from the fermenting beer to the surrounding water. Second you get additional surface area so you more heat is transferred to the air, thus decreasing temp more and bringing it down to match the room temp 99% of the time. Lastly, you can lower the water temp and measure that directly, assuming slow temp drops and rises (ie add small bottles as often as possible, don't add 6 frozen water bottles at the same time)the wort should match the surrounding water pretty much always.

 

[rodwha]

If you have the opportunity to get a fridge/freezer to convert I highly recommend it. Didn't realize I was a slave to the "thermal mass cooler" needing to be back or have someone swap frozen water bottles 3 times a day until I got a chest freezer and could enjoy myself without concern.

 

[Wynne-R]

My carboys are in water up to the level of the beer. The temperature of the beer, as measured with a thermowell, is always within 1̊F, even with a vigorous fermentation.

You can get some wacky readings when the fermentation is slow due to sublimation. For the two or three days of the most active fermentation it stays pretty stirred up.

 

[pricelessbrewing]

Thank you, for taking the thread on track and correcting me. And a correction, I'm using a carboy.

Ok, so I'm not doing a swamp cooler.

But my question is, having my carboy submerged midway with water will keep my wort temp in the carboy/fermenter close to the water temp?

This batch have already 1 week and 3 days fermenting.

People still call it a swamp cooler, and I do too. There is still some passive evaporative cooling occurring, but most of the heat transfer is due to the increased surface area and thermal mass. At this sort of volume, you're probably better off rotating water bottles, rather than trying to rig up a large net of wet fabric to aid the evaporative cooling.

BTW: after 10 days of fermentation, it's probably done and the temp control is the most important in the first 3 days or so. At this point, don't worry about it, in fact decreasing temps after fermentation has slowed could cause a stuck fermentation beacuse too many yeasts might flocc out of suspension early. This is particularly true of english strains.

 

[rodwha]

The info that the water surrounding a fermenting beer will be 5 degrees warmer than the beer because water doesn't loss thermal energy passively (also false).


Well I'm actually speaking from first hand experience and can say that it is not false. Obviously you have not used this method. Rotating frozen water bottles certainly kept my temps in check. This is the forum where others, having done the same, gave me the info. Works fairly well.

 

[rodwha]

I think I misunderstanding you. You are saying that without using frozen water bottles the statement would be false, in which case I'd assume you to be right as it's the frozen water bottles that do the work at keeping the temps in check.

I missed my schedules rotation time and it took almost a whole day to get the beer temp back down where I wanted it. But then I don't recall what the temp split was, but the water certainly warmed up too.

 

[MaxStout]

If you have the opportunity to get a fridge/freezer to convert I highly recommend it. Didn't realize I was a slave to the "thermal mass cooler" needing to be back or have someone swap frozen water bottles 3 times a day until I got a chest freezer and could enjoy myself without concern.

This.

Last year I bought a 5 cu. ft. freezer and STC-1000. Set it and forget it. I use a 25W light bulb in a paint can for the heat source.

But my ferm chamber only holds one fermenter, and occasionally I have more than one going at the same time, so I still use the swamp cooler for the other.

 

[jtratcliff]

Let's just summarize and clarify a bit.

1) during active fermentation, beer temps can be several degrees higher than ambient

2) putting your fermenter in a water bath can minimize temp. fluctuations but will still equilibrate to ambient (or slight warmer as it is taking some heat from the fermenter)

3) rotating frozen water bottles can keep your water bath temps lower than ambient and thus keep fermenter temps lower too. But the fermenter temps will be higher than water bath temps during active fermentation.

4) adding evaporative cooling via towel and fan can lower fermenter temps further.

5) temp control isn't as critical after the first few days of active fermentation.

6) a dedicated fermentation chamber is much easier

 

[LuisCheco]

Let's just summarize and clarify a bit.

1) during active fermentation, beer temps can be several degrees higher than ambient

2) putting your fermenter in a water bath can minimize temp. fluctuations but will still equilibrate to ambient (or slight warmer as it is taking some heat from the fermenter)

3) rotating frozen water bottles can keep your water bath temps lower than ambient and thus keep fermenter temps lower too. But the fermenter temps will be higher than water bath temps during active fermentation.

4) adding evaporative cooling via towel and fan can lower fermenter temps further.

5) temp control isn't as critical after the first few days of active fermentation.

6) a dedicated fermentation chamber is much easier

Good summary. Good job!

 

[pricelessbrewing]

The info that the water surrounding a fermenting beer will be 5 degrees warmer than the beer because water doesn't loss thermal energy passively (also false).


Well I'm actually speaking from first hand experience and can say that it is not false. Obviously you have not used this method. Rotating frozen water bottles certainly kept my temps in check. This is the forum where others, having done the same, gave me the info. Works fairly well.

Actually I have done this as well so no need to be dismissive. I've done it for about 15 brews between moving and leaving my temp control chest freezer behind and now do it for small batches at my new place in a rubbermaid style storage container. Obviously humidity, and ambient room temp play a role, as does the ratio of wort to swamp cooler water volume. Never experienced a fermentation temp higher than 1 degree over the water temp. I just let it sit now, but the first couple batches I checked with my rt600c from thermoworks and they were usually with half a degree.