How viable is Electric Brewing? HERMS

HERMS (Heat Exchange Recirculating Mash System)

Transfering Strike Water from the HLT to Mash Tun in a HERMS configuration

In order to control fermentability of the wort as well as the type of body desired within a beer (e.g. full body for a stout, medium body for an English ale, or light body for a lager), temperature control in the mash is essential. Even with a well insulated Mash Tun it is not uncommon to lose a few degrees of temperature over the hour or so. Also hot spots within the mash bed can occur and although stirring helps reduce these they do have the side effect of increasing temperature loss.

Two common ways of addressing the temperature loss are:

1.Add more hot water to the mash but the problem with this is that the mash is diluted which impacts enzymatic activity and can affect the conversion of starches into sugars.

2.Add heat to the Mash Tun but in the case of using gas this creates hot spots and can cause temperature fluctuations due to the heat going into the Mash Tun vessel itself which continues to be released after the burner is turned off. Use of an electric heating element within the Mash Tun would also create a hot spot with the element itself retaining heat even after being turned off.

A way of addressing the above issues is through HERMS- or RIMS-based brewing systems which recirculate the wort and raise its temperature outside of the mash bed avoiding dilution of the mash and also because the recirculated wort diffuses through the mash bed it helps alleviate the issue of hot spots.

According to an article, is the use of hot water as the heat source that usually incorporates a copper coil as a heat exchanger. The coil is placed in the HLT (Hot Liquor Tank) and used to heat hot water for sparging the mash. The water in the HLT is typically held at around 180 deg F (82 deg C).

The key advantage of HERMS-based systems is the lack of scorching risk due to water doing the heating up of the sweet liquid in the mash as it circulates through the coil within the HLT. Also there is no direct heating of the Mash Tun. The complication of this system comes when the Mash is at the right temperature which usually means diverting the circulating sweet liquid through a loop to by-pass the coil in the HLT.

One key problem that can be encountered with both HERMS- and RIMS-based systems is compacting the mash due to sucking the liquid out of the Mash Tun using a pump, this can be mitigated by using a false bottom or braided manifold. Another solution is to use a Lauter Grant that is gravity filled and then the sweet liquid is pumped out of this vessel.

To build a HERMS-based brewing system

This includes are variety of options:

· Stand – High Gravity recommend the Blichmann Top Tier Brew Stand with optional Pump Mounting Bracket and Utility Shelf.

· Controller – to control the temperature of the HLT and Mash Tun as well as the Pump(s).

· Power Plug Type – can be 3 or 4 prong.

· EBC Configuration – for the ability of the Electric Brewery Controller to support a second Pump and also the length of power cord.

· HLT – this varies in size from 11 to 55 gallons.

· HLT Options – this includes a Heat Exchanger, the Heating Element (5500w), Boil Coil (240v and varies depending on size of HLT). There are also options to upgrade the Ball Valve and type of hoses.

· HERMS Package – comprised of a Chugger pump, pre-assembled Input Manifold for the top of the Mash Tun, connectors, hoses and tie fittings.

· Mash Tun – this varies from 13 to 55 gallons with the increased size being due to the need to hold the grain as well as liquid.

· Mash Tun Options – AutoSparge to govern the flow rate of liquid entering the top of the Mash Tun over the grain bed.

· Brew Kettle – this varies in size from 11 to 55 gallons.

· Brew Kettle Options – this includes a Hop Blocker to stop hops from blocking the output of the kettle when the boil is complete. There are also Thermometer options as well as Heating Element (4500w or 5500w), Boil Coil (240v and varies depending on size of Brew Kettle), ability to upgrade the Ball Valve.

· Plate Chiller – these include Wort Chillers plus connectors

· Pumps – ability to add a second Chugger pump with disconnects and fittings.

For more information about the brewing process, please continue to follow DEGONG Website