full mash sour - how to keep temps up

[ne0t0ky0]

Planning on doing a sour beer and I want to try a full-mash souring technique. This is similar to the sour starter (small mash with grains kept warm), but instead of just doing the starter, you perform your mash, but then keep it at ~120F for 24 to 48 hours. During this period, minimize the O2 intake (to prevent growth of non-lacto bacteria)... my question is; how best to keep the full mash volume (~9g) at 120F for 48 hours?

I don't have a RIMS/HERMS setup with auto-firing heat; though I do have a pump and typically mash/recirc in my 20G pot. I have access to a cooler, but don't think I can hold 120F for 48 hours. I do have some heat/fermwrap that I used to keep the carboy at a specific temp; but I don't think it could keep 9 gallons at 120F ... anyone with experience with this method or have suggestions on how best to keep it near 120F without introducing o2 (or additional water volume)?

Thanks!

 

[scinerd3000]

get a cooler, put hot stuff in cooler with seran wrap over surface to prevent butyric producing bacteria which are aerophilic. You can also do the same thing but build a small heating box out of foam with the seran wrap over the surface of the mash and a light bulb hooked to a thermastat to heat and keep temp. A water bath and aquarium heater is yet another option

 

[scinerd3000]

if you stay at 116 you should be set....I find that is the optimal temp for this...

 

[ne0t0ky0]

get a cooler, put hot stuff in cooler with seran wrap over surface to prevent butyric producing bacteria which are aerophilic. You can also do the same thing but build a small heating box out of foam with the seran wrap over the surface of the mash and a light bulb hooked to a thermastat to heat and keep temp. A water bath and aquarium heater is yet another option

I was leaning toward the aquarium heater/fermwrap but wasn't sure if it could keep it at 116F. Only one way to find out. Time to test!

 

[Jipper]

Igloo cooler mash tun with a fermwrap and heat lamp keeps my mash at 112*F. Make sure to put saran wrap over the top of the mash and push out any/all bubbles that you can see. I go for two days before boiling, and that has worked pretty well thus far, but I recommend trying a 24 hour, 48 hour, and 72 hour sour mash (when you get the time) to see what you prefer.

My co-worker/roommate did a Berliner and sour mashed for 6 days. Turned out to be an amazing beer too (VERY tart). It's a fun thing to experiment with - so don't be afraid to do so!

Good luck, let us know how it goes...

Cheers.

 

[ne0t0ky0]

Igloo cooler mash tun with a fermwrap and heat lamp keeps my mash at 112*F.

What does this look like? Wrap around the outside? I wouldn't think that'd keep things warm enough...

And heat lamp? Are you putting the cooler in a chamber?

 

[Jipper]

I wrap the fermwrap around the outside of the cooler (you can use two if you'd prefer). The cooler stays in the closet (or garage if it's summer - my garage gets pretty hot). If in the closet I use the heat lamp and put it directly above the cooler.

Cheers.

 

[ne0t0ky0]

Excellent; I didn't think just applying the heat to the outside would do it; but that sounds like it works. Very cool.

How often do you check the mash temp? Any constant monitoring? I have two fermwraps that can be hooked up the a ranco temp controller, but no good way to measure the mash temp (no thermowell). Any thoughts on keeping the temp constant?

 

[Jipper]

Yeah the external heat is just to keep ambient temperatures up. The cooler is so well insulated that it almost holds those temperatures on its own to be honest - the fermwrap and heat lamp are there to assist the cooler's insulation.

I honestly don't monitor it constantly. If you wanted to get crazy with it, you could drill out a small hole in the top center of your cooler lid and use one of our stopper/thermowell combinations (this is what I've done). If you decide to do this, please double check the measurements before drilling the hole. I would obtain the stopper thermowell before drilling, just to make sure everything lines up perfectly. Also - please be careful when using power tools...I'm always skeptical when recommending drilling/cutting/sawing etc.

Let me know if you have any other questions or concerns and I will try to help in anyway possible.

 

[ne0t0ky0]

I definitely don't want to get crazy; if your experience has showed a constant temp over a day or two with ambient on the high side, that's good enough for me to give it a try... worst case it seems terrible and I have to pitch it... not that big of a deal.

Certainly not worth the drill+thermowell; I'd probably just switch back to a lacto-starter style and pitch a smaller amount of lacto into the wort instead.

Again, thanks for all of the info!

 

[Jipper]

Sounds good! You may want to take the temperature once/twice a day (while trying not to introduce any oxygen - a difficult task). This is just to check if you're in the range. I've had friends/co-workers sour mash anywhere from 99*F - 120*F, and almost all of them have turned out pretty well.

Good luck and Cheers!

 

[SecretBrew]

I use a 5 gal pot with a heating pad underneath and a blanket over the whole thing for insulation. My heating pad has multiple settings and I can usually do a pretty good job at keeping the temps consistent.

 

[pdxal]

I use a 5 gal pot with a heating pad underneath and a blanket over the whole thing for insulation. My heating pad has multiple settings and I can usually do a pretty good job at keeping the temps consistent.

I do the exact same thing, with good results.