HERMS vs RIMS vs single vessel

All three systems recirculate wort to hold mash temperature. What differs is how they heat it: through a coil in hot water (HERMS), with an element in the wort path (RIMS), or in the same kettle as the grain (single vessel).

HERMS

HERMS stands for heat exchange recirculating mash system. A pump pulls wort from the bottom of the mash tun, runs it through a stainless coil sitting in the hot liquor tank, and returns it to the top of the grain bed. The hot water heats the wort through the coil, so it can never get hotter than the water around it.

• Gentle and steady. No scorching, and the mash holds temperature for as long as you like.
• Easy step mashes. Raise the hot liquor tank a few degrees and the mash follows.
• Sparge water ready. The same hot liquor tank sparges into the boil kettle.
• Trade-off: three vessels take more floor space and more cleaning, and steps are slower than RIMS.

RIMS

RIMS stands for recirculating infusion mash system. The wort runs through a tube with a heating element inside it, straight back to the mash.

• Fast steps, because the element heats the wort directly.
• Compact, with no hot liquor tank needed to hold mash temperature.
• Trade-off: if flow slows, from a stuck mash or a pump problem, the element can scorch the wort. You need steady flow and a safety cut-off.

Single vessel

One kettle heats the water, holds the grain in a basket, then boils after you lift the basket out. A pump recirculates the wort through the grain.

• Smallest footprint and least cleanup.
• Quickest setup, often on a 120V outlet at 10 gallons.
• Trade-off: the whole batch shares one vessel, so big beers and fly sparging are harder.

Side by side

There is a fourth option: the BräuPro uses a mash tun plus a jacketed Unitank that heats, boils, then ferments the same batch. It skips the transfer to a fermenter entirely.

Where to measure mash temperature

On any recirculating system, control the mash from the temperature at the inlet, where wort returns to the mash tun. On a HERMS that is the coil outlet. A probe under the false bottom only tells you when the grain bed has caught up.

Our HERMS

• Hot liquor tank with a stainless HERMS coil, mash tun and boil kettle, in 10, 15, 20, 30 and 50 gallon sizes.
• The coil mounts with a sanitary compression to tri-clamp adapter, so it lifts out for cleaning or service.
• Two brew pumps, one three-vessel controller, steam condenser and CIP spray ball.
• Runs on one 240V, 30A circuit.
• The 50 gallon size makes pilot batches of about 1 BBL.

More on how the mash tun and coil work together: the HERMS mash tun explained.

FAQ

Is HERMS better than RIMS?

Neither is better for everyone. HERMS is gentler and holds temperature with no scorch risk. RIMS steps faster in less space. If you like long, steady mashes and fly sparging, choose HERMS.

Do I need three vessels for good beer?

No. Single-vessel and two-vessel systems make excellent beer. Three vessels give you separate hot water for sparging and more room for big batches and high-gravity beers.

What power does an electric HERMS need?

Ours runs on one 240V, 30A circuit. New to 240V? Size it with the electric brewery calculator.

Can I convert my system to HERMS?

If you already have a hot liquor tank and a mash tun, a HERMS coil kit and a pump turn them into a HERMS.

Is a wort chiller included with the HERMS?

No. Add our counterflow chiller on the product page, or use your own: the kettle outlet is standard 1.5" tri-clamp.