Kettle souring in keggle - maintaining temp

[blizz81]

Optimally, I'd like to kettle sour in my keggle BK with it sitting on the burner stand so I can get it ready on mash day, and then when it comes time to boil, I can just fire up the burner.


Would a ferm heat wrap (+ STC) work ok for this, do you think? I've never used one, trying to ponder 1) how much tape is on them / if it's easy to "bypass" the tape and bungee on / off, and 2) if it would be effective enough on a keggle. Not really asking a lot, I suppose, as I know some brewers don't employ any method for holding temp while they're souring.


Any other ideas?

 

[ten80]

You'll want to maintain approximately 110F, which is really pushing the limits for a ferm-wrap on a large keggle and is impossible without substantial insulation. Temperatures below about 90F will allow bacteria other than Lactobacillus to be active and will ruin the wort.

You may want to read the Milk the Funk wiki article to get a better understanding of what is required to make a good sour wort, then re-evaluate your plans and setup. Also keep in mind that in addition to keeping the mash above 90F, it is important to keep oxygen out of the kettle headspace.

It is not clear to me exactly what your setup is and what your question is regarding the use of "tape."

 

[blizz81]

You'll want to maintain approximately 110F, which is really pushing the limits for a ferm-wrap on a large keggle and is impossible without substantial insulation. Temperatures below about 90F will allow bacteria other than Lactobacillus to be active and will ruin the wort.

You may want to read the Milk the Funk wiki article to get a better understanding of what is required to make a good sour wort, then re-evaluate your plans and setup. Also keep in mind that in addition to keeping the mash above 90F, it is important to keep oxygen out of the kettle headspace.

It is not clear to me exactly what your setup is and what your question is regarding the use of "tape."

Yeah, shooting to maintain I'd say 105-110*F. I'm not sure if it's more or less realistic if you're transferring into a FV, or have a different BK or MLT to do a hot-side / "kettle" sour, but the general attitude I've picked up from the forum is that if anything, people insulate, but a lot of people don't even use any sort of heater to maintain temp. I figured it may be a bit more of a stretch in a keggle. I guess for the cost of a ferm wrap & STC, I may chalk it up to experimentation anyways, as I've had some situations where I've wanted to raise temp on a FV and have had to be otherwise creative.


Re: "tape", I was going off the description of a 40W ferm wrap on Amazon in that it had adhesive on the wrap. I wouldn't want to use that as I'd want quick on / off so I could take it off to boil, etc. I suppose worst comes to worst I could put paper on the tape & use a bungee to secure.

 

[WI_Wino]

I did a kettle sour a couple weeks ago using the Omega lacto blend. I used a brew belt and STC-1000 controller to maintain 75-80F. Soured up nicely in 48 hours.

 

[blizz81]

I might fall back to using an 8gal kettle I have that's been relegated to HLT duty. Tight-fitting lid that can be easily wrapped, minimal headspace, more 'direct' contact with the wort re: the walls of the kettle. Means schlepping the wort between vessels, but could be a better option.

 

[ten80]

I just use some string or a bungee to keep my ferm wraps on carboys or buckets, then wrap the vessel in reflectix insulation and perhaps wrap a towel or down jacket over the top to keep heat in.

Purge the headspace with CO2 if at all possible, otherwise minimize headspace to reduce exposure to oxygen. This is critical to making a clean but nicely sour wort!

EDIT: you can also put saran-wrap directly across the surface of the wort to provide an additional barrier against oxygen. This helps if your souring vessel has a lot of headspace and you cannot purge out the oxygen.

 

[WI_Wino]

I might fall back to using an 8gal kettle I have that's been relegated to HLT duty. Tight-fitting lid that can be easily wrapped, minimal headspace, more 'direct' contact with the wort re: the walls of the kettle. Means schlepping the wort between vessels, but could be a better option.

I did my "kettle" sour in a plastic bucket fermenter dedicated to sours. Filled it right to the brim and snapped on the lid w/ airlock. Not much airspace. Since I boiled after the lacto soured the wort, I was not concerned about possible brett/pedio/etc. contamination from previous fermentations. After 48 hours I had 0 drop in SG.

 

[blizz81]

As an update, I'm doing a water test in my 8gal kettle with the wrap. It definitely seems like it would be tough to hold something like 110-115*F in a keggle...perhaps two wraps + sufficient insulation would be ok, though it might still require a closed space.

I'll be using OLY-605 here in my first go with a gose, so not as important on temp management. So far, sticking it in the basement (coolest spot) and trying to get it to hold an indicated 84*F (liquid seems to be about 4* higher in kettle), it definitely still raises temp, though slowly. And I have a bit of a contact / insulation cover issue with handles on my kettle.