is measured out and milled and about a quart of water is boiled for rehydrating yeast. I fill the Hot Liquor Tank (HLT) with 15 gallons of water and set the RIMS heater control to the specified recipe temperature.
The mash tun is a 40 quart stainless steel pot which has a perforated false bottom that permits liquid to pass but keeps large grain particles out of the pump and heater. There is an array of four ball valves on the bottom outlet of the mash tun that direct the flow of liquids during the process. The pump pulls liquid from the tun and pushes it through the RIMS heating chamber (photo right). The heating chamber contains a 4500 watt hot water heater element controlled by the RIMS controller. There is a temperature probe in the output of the heating chamber that provides feedback to the controller. Liquid returns to the top of the tun via a four port manifold.
Since the brewing and cleanup processes take about six hours, I usually start early in the morning. I turn on the RIMS Controller and start heating the HLT to 170F. It takes a little over an hour to get the HLT up to temperature so I take a breakfast break at this point. When the water is ready, I run enough into the mash tun to just cover the false bottom and circulate it with the pump, to bring all the piping up to temperature, and check for leaks.
The return manifold is temporarily removed and the milled grain is added to the mash tun. Additional hot water, about one quart per pound of grain, is added to the tun. The grain and water is thoroughly mixed and the return manifold is reinstalled. The RIMS pump is started and the flow is adjusted for a gentle return stream. Once the flow is correct, the RIMS heater is turned on and temperature is allowed to stabilize. Once the recipe temperature is stable, I start a countdown timer. Most of my recipes mash for one hour.
At the end of the recipe time, the RIMS heater is adjusted to 168 degrees F. This starts a process known as "mashout". The purpose of mashout is to stop any enzyme action in the mash and freeze the beer profile at that point. The use of mashout is controversial, many brewer do not use it and make great beer, but I prefer to spend the 20 minutes it takes. Old habits die hard.
Next, the mash is slowly rinsed (a process called "sparging") to remove all the sugar possible from the grain. I have rotating arm (photo left), which replaces the return manifold, that sprinkles 168 degree water on the top of the grain bed. Again, the amount of water used is critical, that amount dictated by the quantity of grain. I usually use about 7.5 gallons for sparging, over a 45 minute time period.Read more ...