Please critique this BIAB all in one concept - 30 gallon pot

[NoCornOrRice]

Hi folks, I'm interested in BIAB. I have a 3 vessel E-HERMS, and it has served me well, but it takes up an obscene amount of room. I am exploring BIAB all in one options. Does the concept below look like it could work with my existing 30 gallon mash tun. Pot is 24" high and approx 22" wide. It is an el cheapo one but has worked well as a mash tun. There is enough space to mount an element in the 2 and 5/8ths gap between the bottom of the tun and the stainless false bottom. Do you think I could fire the element while mashing without disaster? I do have all the E-HERMS stuff for control, pumping, etc. What volume of wort could this yield at approx 1050 O.G.? Thx.

 

[jtratcliff]

I wouldn't want the bag sitting directly on the element, but with a false bottom *and* recirculation, you shouldn't have a problem.

I do stovetop BIAB in a 10G kettle... I direct fire on my gas stove to bump up mash temps all the time with no false bottom or recirculation... I just stir well while the burner is on. And that's with direct contact of the bag with the bottom of the kettle.

It's a stove and not a jet burner, so grain of salt and all that... but I've not had any scorching issues... Clearly people have melted their bags, though... you can find examples on here and with a google search.

The bags themselves are good to about 350F I think...

I don't think I've seen any examples of a melted bag with a false bottom... I haven't specifically looked, but most cases I've seen involved direct contact and propane set-ups... YMMV...

 

[RM-MN]

If you mill the grains fine for BIAB there is no need to turn the burner on during the mash. Conversion happens very quickly and unless you are outside at -30 with a wind blowing your mash won't lose heat fast enough to affect the conversion. Keeping the mash temp constant for an hour is only necessary when you have a coarse crush and the starch gelatinization is taking a long time because the grain particles are so bit it takes a long time for the water to get to the starch.

If you want to see how long conversion is taking get some iodine. Take a small scoop of the grains in the mash and put a drop of iodine on them. Keep trying until the iodine doesn't change color. If you never get to that point where the iodine doesn't change, adjust your mill finer.

 

[jdudek]

Pluggin some numbers in brew father (I've never worked with such large volumes), looks like you can reasonably expect a 20 gallon batch, assuming 75% efficiency, typical grain absorption, 1gal/h boil of rate. I got 35 lbs of grain into 25 gallons of water, giving me about 28 gallons of mash, which should comfortably fit your 30 gallon pot. from there it should end in the neighborhood of 20 gallons into the fermenter.

you can fire the element while mashing but it will require recirculating or somehow moving the liquid around, as others have pointed out. Most setups out there seem to have the temp probe closer to the element to ensure water does not get too hot below the grain bed, before the thermometer in another area picks it up and shuts it off.