High fermenting temps

MadScienter

MadScienter

New Member
Trial Member
Joined
Mar 19, 2013
Messages
33
Reaction score
0
Points
0
My last few batches have turned out... weird. Both IPAs, turning out much sweeter than the same recipe in the past. I've noticed that as we get into spring here in San Diego, the temps that my ferment vessels are in are warmer than they should be. 70 or so at night, but 75 to almost 80 at times during the day. I know rapid fermentation can cause "off" flavors or tastes... but I don't really know what that means. Anybody have any experience with high fermentation temps? Does it produce overly sweet, almost sickly sweet flavors, or is there another variable I could be overlooking? Thanks!
 
as a follow up... I DID substitute a large 30 min hop addition of Willamette to Cascade (what was on hand...), but the Cascade has a higher AA than Willamette... so if anything wouldn't that make it MORE bitter? Or do I have that backwards?
 
"Sickly sweet" sounds like underattenuation - your yeast didn't ferment all the sugars. Does the sweetness linger as an aftertaste? That's sugar. Temperature wouldn't have influenced that, in fact, you should get better attenuation (with some nasty flavor trade-offs) at higher temperatures.
 
We'd need to know the yeast, the OG, and the FG to rule out under attenuation. From there the yeast strain will tell us if it is esters causing the new flavor. It may also be a little green still. Put a bottle in the fridge for a good week and see if it improves.

Also, is your yeast pitching rate targeted (are you making a starter?), and is this 1st generation yeast or a re-pitch?
 
I am using starters based on the yeast pitching calculator, always first generation. I actually may have jumped the gun on this a bit... After I let it carbonate in the keg for a couple days, it's tasting much better. I guess I'm still getting used to tasting beer at its different stages. Thanks anyways guys! I appreciate it.
 
Controlling your temperatures during fermentation is a huge part of brewing.
Look at the temperature range for the type of yeast you're using and keep your fermenting vessel at or slightly below the range.
A typical fermentation schedule should start at the lower end of the range with a healthy pitch. Then as fermentation nears the end,(about 80% of expected attenuation) raise the temperature to the higher end of the range and let it stay there until complete.
If you take care of the fermentation, you shouldn't be dealing with "Green" off flavors in your beer.
It's very common for a brewery to produce and have a beer ready for serving in 2 weeks.
Hope this helps.
Brian
 
Is it safe to say it's better to error on a cooler ferment temp, than higher?

With summer coming, what other things should us less experience brewers be aware of,ie, unintended effects of warmer weather (if any)?
 
In the summer, it takes longer to chill the beer if using an immersion chiller, or especially an ice bath.

Brew Mentor hit the nail on the head in terms of temperature control when it comes to yeast.
 
The T-shirt trick works well to keep brews a little cooler and a more consistent temp. Just set the carboy or bucket in a tub or bathtub in a few inches of water, soak an old T-shirt (or towels work) and drape it over the vessel with the bottom in the water. This will drop your vessel temp enough to keep away from those nasty 80's.
 
good stuff guys... thanks. I've been playing with an old kegerator that I use to cold crash, and I'm able to keep it from exceeding 70. Since it's outside, it drops quite a bit at night, so I think I'll drag it in the house to minimize temperature fluctuations. might as well... one more variable under control. it's would be nice to be able to ramp my fermenting temps like that.
 
Yep that's the same paint can article I followed. Also use the same controller.

Does yours flicker on sometimes, when the temp is right on the edge of the setpoint? The sensor will wobble +/- 1 degree for few seconds. Sometimes it comes on for a split second and then shuts off, which can't be good for the freezer compressor. I upped the short cycle delay setting to 10 minutes to try and mitigate that.
 
I haven't seen any issues with the controller yet.
 
Just went out to the shed and drank a beer while watching the temp flip between 66 and 67 every 3-6 seconds for five minutes. Earlier today I set the short cycle delay to 15 minutes (which is the max). The set point is 66, so when it hits 67 it runs for 3-6 seconds, then shuts off when it flips back to 66. It is almost like it needs a minimum run time setting of 1 minute.

I don't have a fan in there, so that could be part of it. Not sure I want to go through the trouble of wiring one in.

The sensor is located on the far side of the carboy away from the heat source. I'll see about contacting the company, hopefully there is any easy fix.

FYI - I have a Control Products TC-9102D-HV Dual Stage High Voltage Digital Temperature Controller, paid $60 on Amazon back in November, 2012. Bilhelm96, this appears to be the same one as yours.
 
LarryBrewer said:
The set point is 66, so when it hits 67 it runs for 3-6 seconds, then shuts off when it flips back to 66. It is almost like it needs a minimum run time setting of 1 minute.
Click to expand...

What you need to so is increase the "DF" by one degree. I use the same controller and found it doing the same thing. Right now I have mine set at 2 with the probe on the side of the fermenter. If I have the probe in open air I set the "DF" to 3, reason being is that the air temp will change much quicker than the fermenter.

Right now I have a stout fermenting at 68 degrees with the controller set to 67 and "DF" set to 2. When the temp ticks up to 69 for even a second it gets cooled until the temp ticks down to 67. End result temp is held between 67.5 and 68.5, and my compressor gets a good run when it does kick on. Now if I am mostly heating I would set the temp to 69 in order to maintain the 68.
 
I also have the differential temp set to 2 degrees. When I had it set at 1, the compressor was short cycling. I do have a small fan in the box which helps regulate the temp.

Confirmed, it is the same controller I have. I got it in Sep 2012 for about $60 on Amazon
 
Indeed the Df was set to 1, just changed it to 2. Thank you!!!
 
Head First said:
The T-shirt trick works well to keep brews a little cooler and a more consistent temp. Just set the carboy or bucket in a tub or bathtub in a few inches of water, soak an old T-shirt (or towels work) and drape it over the vessel with the bottom in the water. This will drop your vessel temp enough to keep away from those nasty 80's.
Click to expand...

MadScienter,
Like you, I live in San Diego County. And like many in the coastal part of San Diego, we don't have air conditioning. Last summer had some long runs of hot weather, and fermentation temps became an issue. I used the T-shirt method placing the fermentors in plastic party tubs and putting them in our guest bathroom shower (the coolest place in our house or garage in the summer). Though it looked a little hillbilly to our summer visitors, it worked very well.

This summer I'll be using a chest freezer with a temperature controller to make it easier.
 
You can also brew some Saisons. Some of the saison yeast stains are supposed to be fermented at 80-85 Degrees.
 
Yep, it's almost Saison brewing season here in Denver.... One comment - I see a lot of interest in controlling the fermentation temps very closely. If it's something you really want to do, fine but as long as you keep it in a few degree range - I prefer the bottom of the yeast's range - the results are generally good.
 
You must log in or register to reply here.
Copyright © 2007-2024 Brewer's Friend, Inc. - Send Feedback - Terms - RSS Feed - Do Not Sell or Share My Personal Information

Back
Top