The last brew house I built was a 3-gallon brew house (4.25 gallons at the beginning of the boil). It was built around the reality that I would need to brew at least one time every month if I was going to manage to keep a yeast bank on agar slants alive while piggybacking subculturing on top making new starter from slant. My kettle was 100% custom. I started with a Vollrath Optio 27-quart induction-ready stock pot. I had a local sanitary welder weld a stainless coupling for a ball 3/8" stainless ball valve. A lot people do not realize that 3/8" used to be a very common ball valve size in the early days. Now, even a non-full-port 1/2" ball valve is not big enough for a lot of brewers and 10 gallons is the old 5 gallons. I am building this brew house as a 3/5-gallon brew house. It uses 5 and 10-gallon Igloo coolers for mash/lauter tuns. The 5-gallon cooler will probably see most the most use. The 5-gallon industrial igloo cooler is much more compact than the 10-gallon industrial cooler. It just limits the grain bill to no more than 13lbs (it is a tight 13lbs).
Speaking of coming to my senses, I scaled back my electrical install. While I ruled out a full-on electric brewery, I really started to enjoy brewing with a 240V portable induction range at the end of my last pass through the hobby. I had been using a 1800W portable induction range, so that I could keep the garage door shut in the winter. It was barely enough to bring my starting volume of 4.25 gallons from mashout temperature up to boiling temperature with the lid on and it could only maintain a weak boil with the lid off, even with insulation. Now, a 3500W 240V portable induction range was a completely different animal. It could bring 7 gallons up to a strong boil from mashout temperate in about 20 minutes and keep it there on reduced power with the lid off. Brewing with a 240V induction range after brewing with an 1800W induction range was an eye-opening experience.
Anyway, brewing with 240V was made possible due to the fact that the gremlins my ex-wife and I had been fighting with our double oven were due to the fact that the electrician who wired our house installed a 30A 4-wire circuit instead of a 40A 4-wire circuit. It never dawned on me that a double oven required 40A service until my ex decided to get a new double oven and the guys who came out to take the pre-install measurements told us that we needed to have a 40A circuit installed. I had local electrician that I had previously used to install a transfer switch install a new 40A circuit for the oven and reroute the existing 4-wire 30A circuit the to garage (I had him come back and upgrade the breaker to a 30 GFCI breaker). The problem with a 30A 4-wire circuit is the huge NEMA 14-30R receptacle, which requires a 2-gang box and cover plate. The receptacle is so big that it almost looks like a caricature. Anyone who has ever plugged a dryer with a 4-prong plug in has seen how stupid big a NEMA 14-30R receptacle is compared to normal household receptacle (A 6-30R receptacle is huge as well). Anyway, I had to fashion a NEMA 14-30P to NEMA 6-20R extension cord, so that I could use the 3500W induction range. I used a 2-gang weatherproof metal box, which allowed me use a simplex NEMA 6-20R receptacle and a switched NEMA 5-15R receptacle for my March pump (I needed to use the neutral wire for something
). That experience drove home the huge cost and size increase going from 240V 20A to 240 30A. A NEMA 6-20R receptacle is the same size as a standard household NEMA 5-15R or 5-20R receptacle and 12/2 NM cable (a.k.a. Romex) is almost half the cost of 10/2 NM cable. Plugs and receptacles are also much cheaper. One can run up to a 4500W element on a 20A circuit (not to exceed 3 hours continuous use at full current draw), so if one already has 120V 15 or 20A service in the area one wants to brew and one brews 10-gallon or smaller batches, one does need to install a 240V 4-wire circuit with a big honking NEMA 14-30R receptacle.