Heating Pad

Hey gang

I have a HG belgian that didn't ferment out as well as I'd like, so I stuck a heating pad under it and turned it on medium. It's been in the secondary over a month. The bubbles have started up again and the airlock is busy, but not rapid enough of a ferment to create any foam at the top.

I don't have a thermometer thingy for my carboy, but the basement's ambient temp is 68. Is medium too warm? Should I turn it down to low and see if it keeps going? It's a standard Walgreen's heating pad; the kind they sell for fifteen bucks.

Since it's so far along I'd think the danger of fermenting too hot has probably passed, but I'm guessing there is still a limit.

Joe

i wouldnt keep it on there. you will heat up the wort too much. the ambient temp of the celler should be fine. you may have just woke up the yeast so turn off the heat and let it finish out.

Oh? a Walgreens heating pad on "medium" should be good? Or "low" might work also. I've only used a Rite-Aid heating pad...oh wait they merged didn't they. I'll see if I can find the data I collected using the Rite-aid heating pad.

All kidding aside...I think you are probably fine, I would go with not warm yet not cool to the touch, how's that for precise advice.

HNY, Mike

Heating pad can work, but I would not put it underneath. Think about it. The yeast and trub settle to the bottom. If the you are unsure of the amount of heat being generated under there and concentrated there it could get wicked hot right where the yeast is causing nasty things to happen. Sure heat rises and the upper stratus of the fermenter may get to be a nice temp but you are cooking the bottom.

Here is one way to use the heating pad. Put the carboy in a box with the heating pad. Stick a probe thermometer into the side of the box. Have the heating pad switch outside the box. Adjust the heat level based on the thermometer reading.

good idea, zy, I'll give it a shot.

FWIW, I did run out and buy a carboy sticker thermometer and it's reading about 75.

68 to 75 seems ideal to me. I'd let it ride.

Update: It's still at 75 after taking Zy's suggestion and placing it under a box with pad alongside instead of under, however, fermentation has slowed by 60% or so from when I had it under the pad. As long as it keeps going I'll let it ride. No hurry, this thing is capable of aging a long time.

Well how about some more details.

You said it did not ferment out as well as you like. What was the OG and where is it now? How did you determine it has "slowed by 60%".

What is your time frame? How long has it been fermenting?

What have been the temperatures it was fermenting at? You say the basement ambient temp is 68F. Has it been down there at that temp for all this time? Chances are good that the wort was actually higher in temp as it was fermenting. Say mid 70's.

Controlling fermentation temperatures is really important and it takes a bit to figure out a system that works for you. Hang in there.

Solution: This morning I put a Peet boot dryer on a chair next to the dresser I had my primary sitting on. I covered the primary and Peet boot dryer with a cloth canvas. It worked great. My wort got to 74 and my room temp is 70 deg.

Problem: I had my house temp set at 73-74 deg and my wort was varying between 67 and 69 degrees. The weather has been below zero consistently every night for the last month, with highs only in the teens, so it has been hard to keep the house warm without using alot of energy. I think I may have to rig something more permanent with this boot dryer.

I use a temperature controller with a heating pad. My heating pad has auto shutoff, so it wouldn't work well without the controller.

A homebrewer can never have too many temperature controllers.

Zymurgrafi said:

Well how about some more details.

You said it did not ferment out as well as you like. What was the OG and where is it now? How did you determine it has "slowed by 60%".

What is your time frame? How long has it been fermenting?

What have been the temperatures it was fermenting at? You say the basement ambient temp is 68F. Has it been down there at that temp for all this time? Chances are good that the wort was actually higher in temp as it was fermenting. Say mid 70's.

Controlling fermentation temperatures is really important and it takes a bit to figure out a system that works for you. Hang in there.

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I haven't checked the SG in a while. OG was 1.080. I will take a measurement tonight if I remember.

The ambient is kept at 68F, never varies, as it's in my basement and controlled by radiant heat through the floor, not connected to the forced air system in the rest or the home. You are correct in that seeing as how I just purchased some sticky thermometers, and my current primary is registering 73 or so, the ferment would have been a bit hotter.

As far as my 60%, that's just a guess. I am just looking at the number of tiny bubbles to measure activity. Very unscientific, I know.

Thanks for all your help.

Bubbles in the airlock tell you nothing. A lot of activity can still be going on after the bubbling has subsided. If you have not taken a gravity reading you should not assume it has not attenuated enough.

Again, how long has it been fermenting? Again, even if the airlock is not active it is VERY likely still fermenting.

It's been fermenting since November 23rd. I had a three hour call with our Asia desk last night and then spent an hour when I got home getting a smoke detector (located 12 feet in the air in a cathedral ceiling) to stop chirping. I did not have time to do another reading but will tonight. I did, however, take a look at the carboy under the box and the temperature had risen from 75 to 77 and fermentation "appears" to have picked up somewhat.

Since it has been in the secondary for a month now, I would guess that you are just releasing CO2 in solution by heating it. Your ambient temperature isn't low enough that temperature would be my first guess as to why you didn't attenuate well.

Still worth a shot though. I would try to swirl the yeast into solution along with the heating.

When I don't hit my numbers, I bottle it and try better next time.

Isn't 75-77 a bit to warm, won't it cause off flavors? i thought keeping it in the mid 60's was ideal and very few things sould go 70+ for long periods.

Zenman said:

Isn't 75-77 a bit to warm, won't it cause off flavors? i thought keeping it in the mid 60's was ideal and very few things sould go 70+ for long periods.

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Remember, it's already been through a primary fermentation and many weeks in the secondary. If you read "Brew Like a Monk", higher temps are OK later in the process; less chance of creating fusol (sp?) alcohols at that point and you can get a better attenuation in HG brews.

svraines said:

Since it has been in the secondary for a month now, I would guess that you are just releasing CO2 in solution by heating it. Your ambient temperature isn't low enough that temperature would be my first guess as to why you didn't attenuate well.

Still worth a shot though. I would try to swirl the yeast into solution along with the heating.

When I don't hit my numbers, I bottle it and try better next time.

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I am not a beer snob and have no issue with the occassional sweeter tasting beer, so I agree with your philosophy. I am approaching it as more of a learning experience than anything.