Mash recirculation is a popular technique. Most of the new integrated single-vessel packages (Grainfather, etc.) include the feature. A growing number of home brewers today incorporate mash recirculation in their BIAB or multiple vessel rigs, frequently adding temperature control through either a RIMS (Recirculating Infusion Mash System) or a HERMS (Heat Exchange Recirculating Mash System). The advantages of recirculating the mash are frequently discussed. One obvious result is a very clear wort. However, the importance of wort clarity is generally considered minimal. The aspect of recirculation that is most attractive is that it can provide a consistent mash temperature, with little temperature variation from region to region within the mash. This should lead to consistent enzyme activity throughout the mash and consistent wort characteristics from brew to brew.
Control Panel
A RIMS setup directly heats the mash as it is pumped through a chamber containing a heating element and then back into the mash tun, or by direct fire of the mash tun during recirculation. The RIMS approach appears to be the more popular choice these days. One advantage of this scheme is that it has fast response and can raise the mash temperature relatively quickly. This is useful when doing step mashes or heating for mashout. The downside is the danger of scorching the mash, though with modern control systems this is probably rare.
Controller And Other Hardware Connectors
A HERMS setup recirculates the mash through a heat exchanger coil suspended in a vessel containing heated water, usually the hot liquor tank (HLT). The temperature of the water in the HLT is thus transferred to the mash indirectly through the coil. A HERMS rig can be either gas or electric. Many HERMS setups rely on direct fire heating, whether fueled by propane or natural gas. The downside is that there is a lot of volume in the heat exchanger chamber or HLT, so a large volume of water must be heated to raise the temperature of the mash; this takes time. A few degrees per minute is considered a pretty good response. Once you reach your desired temperature, of course, maintaining a steady mash temperature is easy with either system. Because of the slow response time, a HERMS can be operated either automatically via a temperature-controlled burner, as in the setup being described here, or manually by watching the temperature and adjusting the relevant burners regulator or needle valve.
Because I am, for now, committed to gas, a HERMS rig is an easy setup for me to implement. I decided to do some tests to see how such a process would work for me. I first rigged a manual system, to verify that I wanted to add HERMS to my home brewery. It worked well, so I decided to move on to automation.
Coil in HLT
My first test fixture used an old 25 foot, 3/8 inch copper wort chiller that was in the spares pile. I suspended it within my hot liquor tank and pumped the mash through it and back into the mash tun. It worked well enough to intrigue me, but the limited surface area caused a slower response than I wanted. I then purchased a 1/2 inch X 50 foot stainless steel coil from Stainlessbrewing.com and suspended it within my hot liquor tank (a converted commercial 1/2 bbl keg). The price was good, shipping was fast, and the quality pleased me. Now I had something that worked. I could manually crank up the HLT temperature and the mash temp followed right along.
Inkbird Digital Temperature Controller And Burner
Next, I temporarily rigged one of my low pressure Hurricane burners under the hot liquor tank and hooked up a Honeywell valve to be controlled by an extra Inkbird ITC-308 I had on hand. With the sensor inserted into the output of the recirculating mash coming out of the heat exchanger, I could set the desired mash temperature and the HLT burner would follow. I was getting about two degrees per minute rise with the burner mounted well below the position I intended for my permanent setup. I expect performance to increase in the final revision because the burner will be mounted closer to the kettle. All systems are go - time to start putting together a real control panel and begin transferring everything over to a new single tier brewstand. With the pumps installed, I won't need the gravity fed system I've been using.
The cooler mash tun will be no more, I will replace it with a 15 gallon SS kettle with a Jaybird false bottom. This will permit the brewing of higher gravity beers in ten gallon recipes, and will also permit directly heating the strike water in the mash tun. I will have three low pressure propane (for now) or natural gas burners (the next phase of the project), with PID control of the MLT and HLT burners and a simple on/off switch for the boil kettle burner. The stand will be a single tier, with one pump for recirculation and sparging, and another for transferring wort to the boil kettle and from the boil kettle into the counter flow wort chiller (unless I finally give in and try my plate chiller instead).
The control panel will be the topic of Part two, which will include a schematic and parts list for the panel. Part three will describe the mounting and plumbing of the burners, solenoid valves, gas manifold, pumps, and RTD sensors. Part numbers of the exotic bits will be included.
For those of you who patiently worked their way to the end of this segment, I thank you and look forward to seeing you again with Part two.
Control Panel
A RIMS setup directly heats the mash as it is pumped through a chamber containing a heating element and then back into the mash tun, or by direct fire of the mash tun during recirculation. The RIMS approach appears to be the more popular choice these days. One advantage of this scheme is that it has fast response and can raise the mash temperature relatively quickly. This is useful when doing step mashes or heating for mashout. The downside is the danger of scorching the mash, though with modern control systems this is probably rare.
Controller And Other Hardware Connectors
A HERMS setup recirculates the mash through a heat exchanger coil suspended in a vessel containing heated water, usually the hot liquor tank (HLT). The temperature of the water in the HLT is thus transferred to the mash indirectly through the coil. A HERMS rig can be either gas or electric. Many HERMS setups rely on direct fire heating, whether fueled by propane or natural gas. The downside is that there is a lot of volume in the heat exchanger chamber or HLT, so a large volume of water must be heated to raise the temperature of the mash; this takes time. A few degrees per minute is considered a pretty good response. Once you reach your desired temperature, of course, maintaining a steady mash temperature is easy with either system. Because of the slow response time, a HERMS can be operated either automatically via a temperature-controlled burner, as in the setup being described here, or manually by watching the temperature and adjusting the relevant burners regulator or needle valve.
Because I am, for now, committed to gas, a HERMS rig is an easy setup for me to implement. I decided to do some tests to see how such a process would work for me. I first rigged a manual system, to verify that I wanted to add HERMS to my home brewery. It worked well, so I decided to move on to automation.
Coil in HLT
My first test fixture used an old 25 foot, 3/8 inch copper wort chiller that was in the spares pile. I suspended it within my hot liquor tank and pumped the mash through it and back into the mash tun. It worked well enough to intrigue me, but the limited surface area caused a slower response than I wanted. I then purchased a 1/2 inch X 50 foot stainless steel coil from Stainlessbrewing.com and suspended it within my hot liquor tank (a converted commercial 1/2 bbl keg). The price was good, shipping was fast, and the quality pleased me. Now I had something that worked. I could manually crank up the HLT temperature and the mash temp followed right along.
Inkbird Digital Temperature Controller And Burner
Next, I temporarily rigged one of my low pressure Hurricane burners under the hot liquor tank and hooked up a Honeywell valve to be controlled by an extra Inkbird ITC-308 I had on hand. With the sensor inserted into the output of the recirculating mash coming out of the heat exchanger, I could set the desired mash temperature and the HLT burner would follow. I was getting about two degrees per minute rise with the burner mounted well below the position I intended for my permanent setup. I expect performance to increase in the final revision because the burner will be mounted closer to the kettle. All systems are go - time to start putting together a real control panel and begin transferring everything over to a new single tier brewstand. With the pumps installed, I won't need the gravity fed system I've been using.
The cooler mash tun will be no more, I will replace it with a 15 gallon SS kettle with a Jaybird false bottom. This will permit the brewing of higher gravity beers in ten gallon recipes, and will also permit directly heating the strike water in the mash tun. I will have three low pressure propane (for now) or natural gas burners (the next phase of the project), with PID control of the MLT and HLT burners and a simple on/off switch for the boil kettle burner. The stand will be a single tier, with one pump for recirculation and sparging, and another for transferring wort to the boil kettle and from the boil kettle into the counter flow wort chiller (unless I finally give in and try my plate chiller instead).
The control panel will be the topic of Part two, which will include a schematic and parts list for the panel. Part three will describe the mounting and plumbing of the burners, solenoid valves, gas manifold, pumps, and RTD sensors. Part numbers of the exotic bits will be included.
For those of you who patiently worked their way to the end of this segment, I thank you and look forward to seeing you again with Part two.