7 Gallon Mash tun/kettle?

[Gadjobrinus]

Having sold off my beautiful ugly spike 20 gallon rig, still want to brew, inside, with my son. I have a 7 gallon stockpot (quality, triple ply, etc.). Assume most beers will have top OG of 16P or so, though may make the baltic porter or barleywine from time to time.

Any thoughts on a realistic wort into the FV I can expect? Lautering in a separate vessel, likely just nested brewbuckets DIY. I think that literally gives a 6 gallon mash volume limit.. The mash vessel now becomes the kettle.

I am suspecting not much, maybe 4 gallons?

Appreciate your thoughts.

 

[MikeCo]

For a finished boil volume you could probably get about 5 gallons max, assuming you fill the kettle to 6 gallons and boil off a gallon. That would give you around 4.5 gallons in the fermenter depending on your losses to the kettle, chiller, etc.

This makes no assumptions about the mash (grain weight, mash thickness) and resulting OG. I think expecting 4 gallons into the fermenter for beers of 16P on average is reasonable.

 

[ba-brewer]

I think the rule of thumb is use a kettle twice your desired volume so 3.5 is for sure safe.

Best case maybe 1gal head space to the rim (watch like a hawk), a .5gal partial covered boil off and .5gal of trub you could get close to 5gal.

 

[Gadjobrinus]

Thanks very much guys. Still thinking on sizing. I am thinking of a dedicated 10gal kettle from spike, likely, but want to keep the brewing all inside on stovetop - measly 31K per burner. So don't know if, say, 7.5 - 8 pre-boil can be brought to vigorous, rolling boil. This would be the limiting factor, and unfortunately an adequately powerful induction is DOA because we don't have access to 220V.

 

[MikeCo]

My range has a 15,000 BTU "power boil" burner, and I can get 7 gallons boiling on it, but it's not vigorous. I doubt you will get a vigorous boil with the burners alone. Some have used a 120v immersible heat stick to help get a stronger boil.

 

[ba-brewer]

Maybe get a 120V to Hot Rod supplement your stove. I use 2 120V elements(2200W and 1650W) to do 10gal batches, I back down to 80% power once it gets to a boil.

 

[RM-MN]

So don't know if, say, 7.5 - 8 pre-boil can be brought to vigorous, rolling boil.

You don't need a vigorous rolling boil. Just a slow churn is sufficient.

 

[Gadjobrinus]

Thanks guys, sone good thoughts. RM-MN, afraid I'm a horribke creature of habit....always brewed this way for several reasons, so depend on the evaporation rate for one. Arguably driving off unwanted volatiles like SMS (contested, I know. Again, creature of habit). Rate and degree of maillards, isomerization rate of a-a's. All arguable I know and I never tried weak boils. When I worked for Goose Island, the lab was awesome and it would have been interesting to do blind testing. Thanks for the idea, if true, would solve the issue, so thanks again!

 

[jerrylotto]

I think that the rate of the boil is less important than just making sure it is open (uncovered).

 

[MikeCo]

Time to get to mash-in and to boil from mash temps is a factor too. My stove top brewing for a 5.5 gallon batch takes a lot longer than when I use propane or a 4500 watt electric element. The time to heat the water/wort adds nearly an hour to my brew day when doing it on the range in the kitchen. The heat stick would certainly speed things up.