It seems like I am always trying to make small improvements to the home brewing rig to make it as functional as I can. This weekend was no different. I ended up changing the propane lines out for flexible versions that are easier to adjust and adding some sanitary fittings and a sight glass to the RIMS heating bar to enable me to clean it more easily and have some visibility if I run into issues during recirculation.
I think my favorite of the additions was the site glass. In the photo above you can see it in the center of the RIMS heating element bar. I like that it allow me to inspect the condition of the heating bar so that I can tell if it needs to be scrubbed and also allows me to check on the fluid volume level of the bar to make sure I am not running dry.
I brewed a batch of Karamel Citra Session IPA over the weekend to test out the new RIMS system that I had built for my home brewery. Sometimes you can test as much as you want, but until you go live with an actually batch of beer, you just never know what is going to happen. Thankfully everything with this batch seemed to work just about perfectly.
There are a couple of things that I would like to make note of for anyone else who is planning on building their own RIMS setup using a similar configuration as mine. Initially the march pump did not seem to want to pass the wort through the RIMS heating chamber. To correct the issue I bypassed the heating chamber and recirculated directly back into the mash tun for a couple of minutes until the work began to clear a bit. After that it passed through the heating chamber with out any issues. Also, as a safety measure I wired my Ranco temperature controller so that the only way that it can be on is if the mash tun pump is active. I would recommend that you do the same in order to help reduce the chances that the heating element engages with out any fluid in the heating chamber. You will also want to check on your flow rate periodically to make sure that the march pump is transferring fluid at the expected rate.
For those of you who are not familiar with RIMS, it stands for Recirculating Infusion Mash System. Basically it is a method for regulating the temperature of your mash tun during the mashing process when the grain starches are converted to sugars. The mash temperature is critical when brewing a beer and a swing of just a few degrees can have a dramatic impact on your finished beer. For instance, a mash temperature of 146F to 150F will create very simple sugars that are easy for yeast strains to convert into alcohol, providing you with a beer that has a dry finish. While a mash temperature of 154F to 158F will create a good deal of complex sugars that the yeast can not digest which makes for a very full bodied beer that will be lower in alcohol.
If you conduct your mash in metal kettles such as the stainless steel Blichmann 20 gallon kettles that I use, you will find that your kettles will shed a good deal of heat during the mash process. In order to maintain a proper mash conversion you will need to either heat the kettle or the fluid inside of it. The problem with adding direct heat to your mash tun kettle is that you risk scorching your grain bed or wort and may also have a large temperature variance at the bottle of the mash tun and the top of it. If you are going to apply direct heat, it is important that you are recirculating your wort with a pump to help minimize those issues. Another potential problem with direct heat is that it can be difficult to monitor and control with out the use of a temperature controller and means for regulating the heat source; if you are not careful your temperature can swing by 5 degrees very quickly.
For the reasons I stated above, I recently started work on a RIMS (Recirculating Infusion Mash System) to help me properly maintain my mash temperature. I am still conducting tests with it but plan on brewing my first test batch of beer this weekend and am optimistic that it will work out well and help me brew the best beer possible. The system is rather simple. I am constantly recirculating the wort in my mash tun via a march pump. The wort flows into a stainless steel chamber where I have an electric stainless steel heating element at the point of entry. At the opposite end of the chamber is a thermowell that is connected to a Ranco digital temperature controller. If the Ranco temperature controller detects that the temperature of the wort has fallen below my target temperature, then it activates the low watt electric heating element until the target temperature is once again reached and then shuts the element off. The wort flows out of the chamber and back into my mash tun via my MoreBeer Ultimate Sparge Arm. Instead of obsessing over my mash temp and constantly fiddling with my burner and pumps, I can kick back, toss the football around with a friend and enjoy a cold beer until my timer goes off! It should make for a more controlled mash and less stressful brew day if all goes well. Once the design is fully tested I will submit another blog entry with more details on how to build one of your own. In the meantime, you can find Ranch temperature controllers and the MoreBeer Ultimate Sparge Arm here.
Infusion mashing is the process of regulating mash temperature by injecting heated water from the hot liquor tank into the mash tun at specific times.
When conducting a step infusion mash, differing temperatures and quantities of water are infused in the mash tun from the hot liquor tank at specific intervals or steps in the mash process to control sugar conversion and extraction.
When conducting a single infusion mash, the room temperature of the grains is compared with the desired mashing temperature and mash water volume. The hot liquor tank is then preheated to the appropriate temperature and the mash water is infused with the grains all at one time. The mash is maintained at a constant temperature until the mash out or sparging sequence begins.
RIMS or the recirculating infusion mash system is a mash infusion system that either utilizes a pump to recirculate the fluid in the mash over a secondary heat source (outside of the mash tun) to maintain the mash temperature, or constantly recirculates the mash onto itself while direct heat is applied to the mash tun to regulate temperature. The fluid is pumped at a rapid enough pace to keep the temperature of the mash at an equilibrium and prevents the wort from being scorched or overheated.
RIMS or recirculating infusion mash system is a mash infusion system that either utilizes a pump to recirculate the fluid in the mash over a secondary heat source (outside of the mash tun) to maintain the mash temperature, or constantly recirculates the mash onto itself while direct heat is applied to the mash tun to regulate the temperature. The fluid is pumped at a rapid enough pace to keep the temperature of the mash at an equilibrium and prevents the wort from being scorched or overheated.