How are You Measuring Fermentation Temperature?

[Clint Yeastwood]

So it sounds like tape is a compromise between hassle and accuracy that works considerably better than nothing.

I should get a thermowell lid for one keg and make a lager called Hasselbrau.

 

[DBhomebrew]

So it sounds like tape is a compromise between hassle and accuracy that works considerably better than nothing.

With insulation, yes. Absolutely. Minimal to no hassle, minimal compromise on accuracy from thermowell, massive improvement over ambient.

I use a square cut off an old blue foam camping pad. I've also used a bubble wrap lined shipping envelope.

 

[Knightshade]

I tape an inkbird probe to the side of my keg which has a little insulating pocket I sacrificed from an old beer koozie. It is set to a 1.5 degree differential based on what my Tilt is telling me is the internal temp.

 

[redrocker652002]

I have not read thru all the posts, but for me, I simply tape the probe of the Inkbird to the side of the fermenter bucket about halfway between the top of the beer and the bottom of the bucket. I tend to set my temp in the middle of the yeast range, so I figure a degree or two isn't going to be too bad. Plug my dorm fridge turned Ferm fridge into the Inkbird and it seems to be working ok so far.

 

[Bassman2003]

Clint, not sure why you created the post if you do not want to change what you are doing already? (which is fine).

Just think about it logically - there is no way ambient air temp can represent what is needed for 3-10 gallons of liquid that has an internal heat source.

My last ferment I noticed the wine fridge temp was reading 54F and I had the Inkbird set to 65F. So that is 11 degrees of compensation to maintain the 65F from a touching the outside measurement. Could be a bit warmer inside. If that was ambient cooling only it might be 75F inside.

If you do not have an Inkbird then it is settled. Or if you do not want to get one. But the "proof" is clear I do not want my beer at 75F when I think it is at 65F

If tape is an issue use the plumber's putty. I stick it on the wall of the fridge in between brews.

 

[Skeeter686]

I can say that I was very surprised the first time I actually had a thermowell in the fermenter and could see the temperature rise. It was something like an 8°F temperature difference. I assumed it would be a couple degrees higher than ambient, but it was closing in on 10 degrees which put me at the top of the recommended temperature range for the yeast I was using. I started more active cooling at that point to keep it from climbing even higher.

 

[corncob]

How much hotter? How much control can you get with a crude system using an Inkbird and Home Depot freezer? Does it actually work?

Is the beer any better? That's all that matters.

An Inkbird may be off by 4 degrees. Does anyone here calibrate them before using them?

I use a thermapen to measure every gravity sample. I figure if my inkbird (or other old controller) starts to drift, I'll catch it. So far, it's within a degree. That's probe taped to the side, no foam.

 

[Clint Yeastwood]

Clint, not sure why you created the post if you do not want to change what you are doing already? (which is fine).

Just think about it logically - there is no way ambient air temp can represent what is needed for 3-10 gallons of liquid that has an internal heat source.

My last ferment I noticed the wine fridge temp was reading 54F and I had the Inkbird set to 65F. So that is 11 degrees of compensation to maintain the 65F from a touching the outside measurement. Could be a bit warmer inside. If that was ambient cooling only it might be 75F inside.

If you do not have an Inkbird then it is settled. Or if you do not want to get one. But the "proof" is clear I do not want my beer at 75F when I think it is at 65F

If tape is an issue use the plumber's putty. I stick it on the wall of the fridge in between brews.

I'm not being obstinate. I'm trying to ask hard questions to get the best answers. I guess it's the lawyer and scientist in me. I plan to try the foam thing on my next beer.

The mods changed one of my posts to say I started brewing in the Nineties! I started in '02. I made the mistake of saying I started under Bush I when it was really Bush II.

 

[Jonakr]

I'ma use the Inkbird dual temp controller ITC-308's thermocouple taped to the side of my fermenter for an instant read. I augment that with an Inkbird IBS-TH2 recording thermometer so I can has a record.

I just have the 308. It's set to the lower range of my two primary yeasts, so I just tape the thermocouple to my current new batch and let it run.

 

[CDS]

I've always just measured ambient too. I've got an Inkbird 308 regulating the temp inside a fridge holding my 14-gallon conical. The plumbers putty idea seems like a low-overhead method if it's really going to make a difference. Does the fermenter material matter? I notice in David Heath's video, he was demonstrating on a plastic fermenter - any reason to think a stainless steel fermenter would be different?

 

[corkybstewart]

I've always just measured ambient too. I've got an Inkbird 308 regulating the temp inside a fridge holding my 14-gallon conical. The plumbers putty idea seems like a low-overhead method if it's really going to make a difference. Does the fermenter material matter? I notice in David Heath's video, he was demonstrating on a plastic fermenter - any reason to think a stainless steel fermenter would be different?

Stainless should be better, plastic has some insulating properties.

 

[ncbrewer]

Stainless should be better, plastic has some insulating properties.

Yes, I've found that from my readings. I use a plastic bucket fermenter. I find that the reading on a fermometer is about 0.9*F + 0.1*A, where F= Fermometer reading and A=Ambient temp (not including the fermometer correction). This is pretty crude, but close enough for me in my ale fermentation temperature range. If fermenting lagers, more accuracy would probably be needed, but my fermentations are normally in the mid to upper 60s during the active phase. After that, accuracy is less important.

 

[Clint Yeastwood]

Here's another problem. I was taught to pitch yeast at 70-80 degrees, but we generally ferment ales in the 60's and lagers in the 50's. So how much damage am I doing after pitching, while I wait for my fermenter to cool to ideal fermentation temperatures? It takes quite a while for 5 gallons of wort to go from 75 degrees to 65 in a refrigerator.

I've been reading that the temperature is most important during the a most active stage of fermentation. For some beers, that starts in a few hours. I pitched a heavy ale at something like 8 p.m., and the next morning, CO2 was blowing out of the fermenter.

Should we be making starters at fermentation temperatures? That would be a huge hassle. I would have to put my stir plate inside a refrigerator and let the cord hang out through the door, inviting garage bugs to visit. Should we make starters at room temperature and then chill before pitching? That could be hard on the yeast, if yeast is as fragile as people say it is.

Is the answer to pitch warm and start fermentation under pressure to reduce the fermentation by-products while the fermenter cools?

I ferment in Torpedo kegs, so I can pump a fermenter up with CO2 right after pitching if I want.

To make things more confusing, I just saw an interesting Brulosophy article in which lager yeast was pitched at different temperatures (80 and 48), and the writer said he preferred the warm-pitch results.

To add a final layer of complexity, I make a 73% wheat beer with WB-06, and when following my reckless methods and finishing at 68 (ambient), the off-flavors, if any, were too subtle for me to confirm. I would get all sorts of esters with a different beer.

 

[Ninoid]

How do people here measure the fermentation temperature of their beer?

When I got started back during the early 90s, I assumed that if a recipe said to ferment at x degrees, I was to set the fridge at x and not measure the temperature of the beer. I had no way to check on the beer itself. I figured everyone else did it the same way.

I haven't really changed anything, since the beer comes out fine.

If I see a recipe for beer, can I assume the listed fermentation temperature is the actual temperature of the beer, or are there old recipes that just give the temperature of the surroundings?

Seems like it would be difficult to keep the beer temperature steady, since the yeast will give off different amounts of heat at different stages of fermentation.

Are people using those little strips that stick to the sides of fermentation vessels, or what? I have laser thermometers, but they're not ideal for measuring the temperature of shiny objects like kegs. I have used a marker to blacken little spots on kegs, and I shine my laser thermometer at the marks. Don't know if it actually works.

I also use a laser thermometer to measure the temperature of the plastic fermenter. I know it's not very precise, but anyway, I don't have the possibility to regulate the fermentation temperature (a little air conditioning in the room where the fermenters are located for the hottest days), so it serves me only as an orientation.

 

[DBhomebrew]

It takes quite a while for 5 gallons of wort to go from 75 degrees to 65 in a refrigerator.

Faster when you're regulating FV temp rather than fridge temp. That fridge will continue getting as cold as it can get all the way down to FV @ 65 rather than calling a break when it gets to 65.

It takes just a couple hours for my 4gal batch to go from ~90-95 to mid-60s. Granted, that's in a freezer not a fridge.

 

[ncbrewer]

Here's another problem. I was taught to pitch yeast at 70-80 degrees, but we generally ferment ales in the 60's and lagers in the 50's. So how much damage am I doing after pitching, while I wait for my fermenter to cool to ideal fermentation temperatures? It takes quite a while for 5 gallons of wort to go from 75 degrees to 65 in a refrigerator.

How to Brew, E4 suggests pitching when the wort is at fermentation temperature. Yeast suggests pitching when the wort 1 - 3 F below fermentation temperature. Do you have the capability of cooling to the suggested range?

 

[corkybstewart]

Here's another problem. I was taught to pitch yeast at 70-80 degrees, but we generally ferment ales in the 60's and lagers in the 50's. So how much damage am I doing after pitching, while I wait for my fermenter to cool to ideal fermentation temperatures? It takes quite a while for 5 gallons of wort to go from 75 degrees to 65 in a refrigerator.

I've been reading that the temperature is most important during the a most active stage of fermentation. For some beers, that starts in a few hours. I pitched a heavy ale at something like 8 p.m., and the next morning, CO2 was blowing out of the fermenter.

Should we be making starters at fermentation temperatures? That would be a huge hassle. I would have to put my stir plate inside a refrigerator and let the cord hang out through the door, inviting garage bugs to visit. Should we make starters at room temperature and then chill before pitching? That could be hard on the yeast, if yeast is as fragile as people say it is.

Is the answer to pitch warm and start fermentation under pressure to reduce the fermentation by-products while the fermenter cools?

I ferment in Torpedo kegs, so I can pump a fermenter up with CO2 right after pitching if I want.

To make things more confusing, I just saw an interesting Brulosophy article in which lager yeast was pitched at different temperatures (80 and 48), and the writer said he preferred the warm-pitch results.

To add a final layer of complexity, I make a 73% wheat beer with WB-06, and when following my reckless methods and finishing at 68 (ambient), the off-flavors, if any, were too subtle for me to confirm. I would get all sorts of esters with a different beer.

So I'm not the most technical brewer around, I take my brewing seriously but don't get overly worked up on the science. Having said that I've entered 8 beers in legit competitions and have 3 medals and 2 beers made the finals. I pitch my yeast 3-5 degrees below fermentation temperature, and fermentation is at the low end of recommended temperatures. I don't have any scientific articles or research to back it up but this is the technique I have used for 25 years with great success. The temperature is going to rise, so I start low so there's a cushion for my cooling system to avoid getting overwhelmed.

 

[fluketamer]

i have a temp strip on the side of the fermenter.
when i use the ferm fridge in the spring and summer i tape the inkbird thermostat to the fv with foam reflectex .

when i just use the cellar in the winter and fall (55 to 59 degree. ) i tape a cheap meat thermomter to the side which is about 4 degrees off but i know that so it doesnt matter, lol

 

[BongoYodeler]

I currently use a Rapt Pill to measure the near real-time temperature of my fermenting beer. As of now I don't have a fermentation chamber per se, I'm using a Cool Brewing insulated fermentation bag. I swap in frozen 1.5L water bottles to keep the temperature as stable, and close to desired as I can, based on the Pill's readings. My goal is to eventually buy a used upright freezer and a heat belt and keep my fermenter in that, and use a Rapt temperature controller which gets its input temperature directly from the Pill, via bluetooth, and adjusts accordingly.

 

[Clint Yeastwood]

So I'm not the most technical brewer around, I take my brewing seriously but don't get overly worked up on the science. Having said that I've entered 8 beers in legit competitions and have 3 medals and 2 beers made the finals. I pitch my yeast 3-5 degrees below fermentation temperature, and I fermentation at the low end of recommended temperatures. I don't have any scientific articles or research to back it up but this is the technique I have used for 25 years with great success. The temperature is going to rise, so I start low so there's a cushion for my cooling system to avoid getting overwhelmed.

How do you get your starters down to those temperatures before pitching?

 

[day_trippr]

Cheers!

 

[Willy]

Inkbird sensor in the thermal well port if using CF-10. If using SS buckets or plastic buckets I use an ispindel and a thermometer tape on the side.

 

[corkybstewart]

How do you get your starters down to those temperatures before pitching?

I use the normal techniques to make my starter. But in the morning on brewday I put it in the fridge to make the yeast fall out so I can pour off the liquid. As I am pumping my cooled wort into the fermenter, I refill the starter flask with cooled wort and as soon as the fermenter is full I add the starter. Again, I have no scientific research to back it up as a good idea, but over the years I've tried a lot of different things and this is one that seems to help kickstart fermentation. Plus the idea of adding that old stale wort that is not what I'm brewing doesn't sit well with me. If I'm brewing a hefeweizen but I made my starter with DME, I don't want that DME in my beer.

I reread my post. What I meant is that when my wort is 3-5 below fermentation temp, I pitch the yeast, but it's at roughly the same temp as the wort.

 

[acrowe]

That's why one might measure the beer temp. Depending on size of batch and gravity, the beer temp can be 5+° over ambient. Your car's thermostat measures oil temp, not ambient, yeah?

Not really the best analogy. For most cars the thermostat doesn't actually give you a measure of temperature just opens and closes coolant flow at a particular set temperature.
The vast majority of cars actually give you an indication of coolant temperature not the oil temperature.
But it is true that fermentation is affected by the temperature of the fermenting wort/beer regardless of ambient temp.

 

[DBhomebrew]

Not really the best analogy. For most cars the thermostat doesn't actually give you a measure of temperature just opens and closes coolant flow at a particular set temperature.
The vast majority of cars actually give you an indication of coolant temperature not the oil temperature.
But it is true that fermentation is affected by the temperature of the fermenting wort/beer regardless of ambient temp.

Yeah, I was waiting for someone to call me out on that. Still, measuring coolant temp, not the air under the hood.

 

[Ninoid]

How to Brew, E4 suggests pitching when the wort is at fermentation temperature. Yeast suggests pitching when the wort 1 - 3 F below fermentation temperature. Do you have the capability of cooling to the suggested range?

I pitch the yeast a few degrees Celsius above the target temperature because the yeast needs some time to activate anyway so the temperature drops in the meantime.

 

[DonT]

How much has the beer improved?

A lot.... any real temp control can be a big step. My flex+ and glycol chiller now lets me change temp quickly and also lager, which the fermentation chamber couldn't do.... also improved oxygen avoidance and pressure ferm...

 

[Clint Yeastwood]

I think this thread will be very helpful to me with future batches. I'm thinking I should do exactly what I'm doing now with beers that already come out perfect, because you don't fix what ain't broke, but with beers I'm not completely happy with, I can use the foam thing and try to get my wort and starters down close to fermentation temperatures before pitching.

I make an ale that has a little more banana flavor in it than I want, so it would be a good place to start.

 

[Bassman2003]

Just get in the habit and do these things every brew. Make the starter at room temp, let it finish out and put it in the fridge the night before. Pour or siphon off the nasty wort/beer and pitch in your batch. Yeast prefer to go up in temp than down in terms of activity.

 

[ncbrewer]

Here is what's on my mind.

View attachment 864067

I like that concept. That's one reason I use dry yeast (in addition to concerns about shipping during the hot months and shorter shelf life). Starters aren't an issue - hassle is zero.