RIMS and HERMS are the two most popular advanced brewing equipment systems in the world. They enable brewers to attain a target mash temperature; they also help maintain a specific temperature. They ensure that the temperature is consistent throughout the mash, and they generally automate the brewing process. Also, they enable brewers to perform step mashes without difficulty.
Below are details you need to know about these two brewing systems.
Recirculating Infusion Mash System (RIMS) and Heat Exchange Recirculating Mash System (HERMS) brewing systems are recirculating mash brewing systems. When your brewing system reaches a 10-gallon (38 l) size, it becomes tough to move big (100 lb/45 kg) pots full of hot wort around; because of this challenge, many brewers incorporate a brew pump to transfer the wort. And then, if you have a pump around, you can also use that pump to recirculate the wort through the mash.
Recirculating wort through the mash offers you the opportunity to control the temperature of the mash. It also decreases hot spots in the grain bed and gives your wort clarity. RIMS and HERMS systems both use a recirculation pump that will help control the temperature of the mash, and the only way they vary is in how they heat the wort and control the temperature. But both systems incorporate a heat source, and they can be operated without an insulated mash tun.
In a RIMS system, the heating pump runs ceaselessly, recirculating the wort from the base of the mash tun to the top. The heating element could be gas or electric, and it directly heats the pipe through which the wort flows. To attain temperature control, you will have to turn the heating element on and off as the wort continues to recirculate. If the wort is recirculated this way, it helps to enhance clarity by filtering wort through the grain bed during the mash. Plus, it also helps to maintain an even temperature throughout the mash, and it allows brewers to raise the mash temperature effortlessly when it is required. A simple electronic controller and temperature probe are usually used to turn the heat on and off.
In a HERMS system, the mash is also recirculated from the base to the top, but in this aspect, the pipe passes through a heat exchanger or coil that is usually immersed in the hot-liquor tun (HLT). The temperature is regulated by turning the pump instead of turning the heating element on and off. Heat is gotten from the HLT. In the HERMS system, a simple controller is utilized to cycle the pump to regulate the temperature.
RIMS and HERMS are not the only brewing systems; there are a few other systems. Some two-vessel systems, such as the Blichmann BrewEasy, use a Kettle-RIMS (K-RIMS) that recirculates wort through the boiling pot to heat it.
The difference between RIMS and HERMS
A Heat Exchange Recirculating Mash System (HERMS) is very similar in theory to the RIMS. The significant difference is how the wort is heated after it leaves the mash-lauter tun (MLT). While a RIMS system relies on direct heat, a HERMS system makes use of the hot water contained within the hot liquor tank (HLT) that will eventually be used for sparging. Wort goes through a coil of metal tubing, usually copper, that is within the HLT. As the wort flows through the coil, heat is transferred from the hot water, through the metal tubing, and then into the wort. But apart from this significant difference, HERMS is the same as RIMS. While RIMS runs the pump nonstop and varies the heat source, HERMS turns the pump on and off to control the temperature, drawing heat from a fixed source such as the HLT.
Advantages of RIMS and HERMS
Here are some benefits of using the RIMS and HERMS advanced brewing systems.
- When you continuously recirculate your wort through the grain bed, you end up with a much clearer wort than you would when you use a simple manual vorlauf. Too many brewers, it is always better to have a clearer wort going into the boil kettle than to have a cloudy one.
- With the RIMS and HERMS brewing system, the mash temperature can be easily controlled more precisely than possible when using a cooler for your Mash Tun. And one fantastic thing about this temperature control is that you are assured of getting the same wort you initially planned on deriving when designing the brewing recipe. But if you are using a cooler for your mash tun, you are most likely to experience a three or four (or more) degree temperature drift, and it is even more challenging to control the specific enzymes working on your beer. And your final beer may or may not end up as you wanted it to be when you first designed the mash schedule. As a professional brewer, it is always better to have precise temperature control over your mash so that if your beer comes out differently from the way you had initially hoped, you can tweak the mash temperature the next period you would be brewing and be more comfortable with your final results.
- Repeatability is one significant reason why so many brewers are beginning to upgrade to the RIMS and HERMS brewing systems. As you progress in your homebrewing skills, you will start to create recipes that would become your favorite and you would like to repeat. And the ability to tweak one of your recipes and get predictable results is a primary reason for upgrading your brewing system. One other thing about using this advanced brewing system is your being able to get consistent results, such as repeating last year’s Christmas beer that everyone in your family enjoyed. Repeatability is essential when brewing on a small scale. As a brewer, if you can’t repeat your recipe on a small scale, it will be difficult for you to do that on a large scale.
- Another advantage of a RIMS-HERMS system is that you can carry out many complex mash schedules on them. The RIMS-HERMS systems enable you to easily step through your temperature stops with little effort on your part. You don’t have to perform boiling water infusions or decoction mash additions to raise your mash temperatures to the next stop.
Disadvantages of RIMS and HERMS
Below are a few disadvantages of using a RIMS or HERMS system.
1. They are expensive
These systems are pretty expensive to build and even more costly to buy. For example, if you buy a full-on brewing system, you will likely get it for $4,000 or more. Some homebrewers who cannot afford it contribute money to get one and use it together.
2. Cleaning
If you detest cleaning, you might not like using the RIMS and HERMS brewing systems. The plenty of pipes, pumps, and hoses found in these systems means you will have to spend more time cleaning them after a brewing session.
3. Decoction
If you belong to the category of brewers that love decoction, then you won’t love using the RIMS and HERMS brewing systems.
4. Complexity
If you are a beginner in brewing, the complexity of these two systems would be a big problem for you. So, it is always better you know the basics before delving into using any of these advanced systems. It will make you a great brewer in the long run. RIMS and HERMS are more complex than cooler-based systems.
5. High maintenance cost
The RIMS and HERMS brewing systems have a lot of parts that can break and will need maintenance. And all these things will require you to spend money to get them fixed. But if you are a brewer with excellent welding and electrical skills, using these systems won’t challenge you.
Brewing sculptures
RIMS-HERMS brewing sculptures are another relevant thing you should know much about as a homebrewer.
A brewing sculpture is a structural device that not only holds the brewing vessels but also houses all the various accessories used on the systems like the pumps, burners, chillers, plumbing, etc. Brewing on a sculpture enables you to manage all the processes that are involved effortlessly.
There are three popular designs for RIMS-HERMS brewing sculptures. They are:
- The Single Tier RIMS-HERMS system.
- The Two-Tier RIMS-HERMS
- The Three Tier RIMS-HERMS
Whatever design you decide to use depends on how you want to brew and how complicated you can afford to get.
All three designs have similar features.
Their burners are usually mounted to the frame with wind guards.
Their fuel (propane or natural gas) is typically fed from a manifold to control every burner.
A lot of brewing sculptures are made of steel and can either be welded or bolted together. Some brewers get old steel bed frames for their sculptures, and that way, they can save a lot of money on raw materials from the beginning.
Let’s talk about each system in depth.
1. Single tier brewing system
A Single Tier Brewing Sculpture is well known for several reasons. In this system, all three vessels are positioned at the same height, and the required height is usually designed to be relatively low, so the brewer can look into the vessels to monitor the action. Here, you don’t need to climb for doughing in or stirring. It is much safer than the three-tier brewing system because there is no vessel above your head.
But one thing that discourages some brewers about this system is that it is usually more expensive to build because it will require one or two pumps to work, and in terms of size, it can be much larger than the brew-tree design.
If you use this system, you will need only one single pump to facilitate a batch sparge, but you must have two pumps to fly sparge (moving the sparge water to the MLT and the other to move the hot wort to the BK).
2. Two-tier brewing system
The Two-Tier RIMS-HERMS Brewing Sculpture has two vessels at the same height and one below or above. One of the transfers can be made by gravity, while the other will need a pump (or some manual means of transfer). One prevalent example of the two-tier brewing system is Sabco’s Brew-Magic system. It is pretty popular because it is not as tall as a three-tier system.
You can decide to have the MLT low, so it does not require a ladder to dough in or stirring the mash, but it still needs a pump to move either water for sparging or the wort to the BK (however you choose to set it up).
3. Three-tier brewing system
This system uses gravity to move the fluids from one vessel to another and eradicates the need for pumps. This option is a great one, especially when brewing where there is no electricity.
All three vessels are mounted at different heights so water and wort can be drained to other vessels as the brewing process continues.
The top vessel is usually the HLT (Hot Liquor Tank), where water is heated for strike water and sparge water. The middle vessel is the MLT (Mash/Lauter Tun), and the lowest vessel is the Boil Kettle (BK). Water is heated in the HLT and drained into the MLT for the mash and for sparging.
The wort is then drained into the Boil Kettle beneath during sparging before it is eventually boiled. Some brewers have the boil kettle high enough to position a fermenter on the ground below the BK to enhance the draining of the wort into its final vessel for fermentation.
There are two popular designs for the three-tier systems:
- The Brew Tree type design where the vessels are all mounted off of a single straight pole at the same graduated heights required for gravity draining. The Brew-Tree style design uses a tiny footprint, and it is very portable. It is very affordable to build and should use very little if any plumbing. With this system, you will employ either sparge (batch or fly).
- The three-level step design can take quite a few different forms. Some ways of getting this step design are using a ladder or building the three steps into a sculpture. Another is to use whatever natural or manufactured devices you have available, like countertops, tables, ice chests, etc.
Some disadvantages of these types of systems are:
- The HLT is usually positioned above your head, and the MLT is high enough that you would be forced to use a ladder when doughing in.
- You will also need to use a pump and plumbing if you want to recirculate the wort.
- You will have to brew outside most of the time since the system is relatively high.
Conclusion
RIMS and HERMS are two sound systems you should desire to have someday as a homebrewer. One beautiful thing about these systems is that you can have fun while homebrewing because it is less stressful to operate.
Your preference for one over the other is mainly dependent on what you want. HERMS uses lesser parts and less energy for most single-infusion mashes, but you may love RIMS if you are a brewer who routinely performs stepped temperature mash regimens.
As soon as you get either of these advanced systems up and running, you would feel satisfied that it was worth it.