Ragtop232

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The inner grain basket is about 1" shorter than the outside kettle allowing the lid to be placed on the outer kettle for the recirculation. I bring the strike water to temp first, then dough in with the pump and element off. Next, I start the pump without the element to set the grain bed and get the recirculation flow set. I am normally recirculating a stream about the size of a pencil. Once this is stabilized and the water levels are stationary, I then turn on the element. I suspect I'm recirculating about a gallon a minute. Never had a problem with inner basket overflowing.

Jim

cliffhanger1821

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Really like your system, I think I might copy parts of it if you don't mind! I found a 42 qt pot that can slide into a stout kettle with a little less than an inch of clearance all around, was thinking of using that with some 3-4 inch legs.

I read you have 3 gallons of dead space under the inner pot, do you calc your water/grain ratio and then just add three gallons? I usually do three vessel so i guess i am unsure of what ratio you shoot for with biab? What do you think you could get up to as far as o.g.? Are barley wines or imperial stouts out of the question?

Thanks, sorry for the inquisition

Ragtop232

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When figuring the water, I treat exactly as BIAB, meaning all water goes in the kettle for mash, no sparging. So, I calculate how much water I need by the following: How much I intend going to the fermenter (5.5gal) + boil-off rate (90 min. = 1.75 gal) + Grain absorption (1 gal) + loss to trub (.5 gal). So, for my batch, the mash in water would be 5.5 + 1.75 + 1 + .5 = 8.75 gallons. With the area under the grain basket (it's about 4" above the bottom) = 3 gal + space around the grain kettle = 1.25 gal that leaves 4.5 gal of liquid per 11 lb of grain (my normal grain bill for APA ~1.055 OG) That makes a fairly thin mash of 2 qts / lb . I use a rebel brewer grain mill and grind @ the default setting which is a fine grind, but efficiency is stable at ~83% on all brew sessions so far with no problems recirculating.

Jim

orangehero

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When calculating mash thickness, you must include all of the water as what matters is the dilution of the enzymes (and other soluble components). You mash thickness is actually 3.2 qt/lb.

Ragtop232

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While you are technically correct in your calculations, for the sake of illustration, I was setting a point of reference for the water/Grain ratio that is ACTUALLY in the grain kettle. This will give an idea of the water that is in the bottom dead space and to the mash thickness actually in the grain kettle.

Jim

cliffhanger1821

Recipes 

Thank you, I appreciate the feedback. How high up in the inner kettle do those 11 lbs of grain go? How many more lbs of grain do you think you could fit? I typically like to make beers with an o.g.of 1.070 - 1.080. Hoping this system will work around there, definitely need a way to simplify my brewing process. Thanks again. Greg

Ragtop232

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Greg, 11 lbs is about half of the inner kettle. I would say 20 to 22 lbs would fit in the inner grain basket without a problem.

Jim

cliffhanger1821

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Nice! Does your kettle have a conical bottom? It looks an awful lot like the stout tank I want for my build...

Ragtop232

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Greg, no conical bottom on the kettle. However, there's an area in the center, I'm guessing about 7" diameter, that is indented and after whirlpooling would hold some of the trub.

jonurban

Recipes 

Great write up, it definitely has me thinking... do you think a keggle would work as an outer kettle?