Although our volume limiting factor with our setup is our Boil Kettle, we wanted a larger Mash Tun and Hot Liquor Tank to allow for future growth. We decided to purchase some used kegs and convert them into the necessary vessels. Unfortunately, we didn’t know anyone who could weld stainless, so we resorted to taking them to a local fabrication shop to chop open the tops and weld on some valves and nipples.
On both the Mash Tun and Hot Liquor Tank, we built sight gauges so that we can tell how much liquid is inside. The glass tube in the middle is surrounded by what was the dip tube of the original keg before we converted it. It's solid and it prevents the glass from accidentally getting bumped and broken.
Inside the MT, the grains sit on top of the perforated stainless steel sheet. It's slightly elevated off the bottom of the keg and this allows the liquid to flow through the grains. The copper tube coming out of the wall extends below the false bottom and allows the liquid to drain out of the MT without it getting clogged by the grains.
As the liquid flows through the grains and out of the MT, it drains into this March pump which pushes it back up into the Hot Liquor Tank and through the heat exchanger. The great thing about March pumps is that they’re able to withstand boiling temperatures and using the ball valve above it, we can scale back the flow without damaging it.
Here’s our Hot Liquor Tank. It’s constructed similarly to the mash tun except in the upper right you can see some copper tubing (heat exchanger) coming out of it. During the mash, this is where the wort enters.
During brewing, the hot liquor tank is filled with hot water and as the wort from the mash tun flows through the heat exchanger, the surrounding water will regulate its temperature. If it drops below the temperature set point, the burner underneath the hot liquor tank kicks on and increases the temp until the controller tells it to turn off.
Our volume limiting factor…the boil kettle. This is the vessel that we were using back in the extract days. It’s a great kettle, but at only 10 gallons, we’re pretty much limited to doing 8 or 9 gallon full boils.