HEATING OPTIONS PART 1 – ELECTRIC BREWING SYSTEM

In this article we’re going to take a look at electric brewing. When opening a brewery, a key decision is which brewery heating solution to choose. The three main choices are electric, direct fire and steam.

Deciding the best option for you isn’t an easy one, with many factors at play. The first heating solution we’ll look at is electric, it’s common to use this option for smaller brewhouses as it’s generally the cheapest option to install.

 

Electric Brewing in Your Brewhouse

The difference with electric heating compared to steam or direct fire is the heating is applied internally rather than externally in the brew kettle. The electric elements are inside the vessel so, immersed in the liquid being heated.

This makes energy transfer higher and depending on the size of your vessel, you’ll most likely have between 2 and 4 elements per tank.

You control these elements and heating one of two ways:

  1. Each element has a separate on/off switch, so a brewer can turn them on/off as needed.
  2. Use a dedicated control panel for finer accuracy so, you can regulate percentage output for each element and/or have a set point for your chosen temperature.

Mashing In

There are two main way to mash in, where you mix hot water and malt, converting the starch in the grain to sugar. The first is single infusion mash, where you go in a set temperature and rest for one hour at this temp.

Then you’ve step mashing, where you heat the mash to different temperatures “steps” over time. If you’re making a Hefeweizen for example; you might want to mash in at lower temperature at first for a protein rest. Then heating later for further rests, such an amylase one at a higher temperature.

If you’re happy with a simple infusion mash then it’s the cheapest option. As you don’t need any form of heating in your mash tun. It’s possible to make good beer this way with today’s modified malts.

With single infusion you use the temperature of your mixing water (strike water) to regulate temperature of the mash. If you want a mash temperature of say 65°C, then you’ll set temperature of your strike water to 72 to 75°C. Knowing that adding of malt will lower the overall temperature.

The one downside to this option is you can’t heat up the mash to “mash out”. Nevertheless, as your sparge water is going to be hotter for lautering 78°C (172.5°F), your mash will slowly raise the temperature anyway.

 

Step mashing with Electric Brewing

It is possible to heat your mash in an electric brewhouse with there being two main options. Neither is perfect (and will raise you CAPEX) but here they are:

HERMS (Heat Exchanger Recirculating Mash Systems)

With a HERMS system, the mash is recirculated out of you mash tun through a coil inside your HLT (Hot Liquor Tank) and back to the mash tun. The temperature being regulated by the water temperature inside you HLT.

The main advantage of this system, is it’s impossible to heat the mash above the temperature of the HLT. Meaning there’s no risk of overheating the mash and extracting bitter tannins.

The downside is having to regulate the temperature of the HLT according to the mash temperature needed. This could make your brew day longer, needing to wait on you HLT temperatures at different times throughout the brew.

RIMS (Recirculating Infusion Mash Systems

When you’ve a RIMS system in your brewhouse, the wort is pumped over a heating element in a tube. The element heats the wort, raising the temperature of the mash to your desired target.

Having an external dedicated heater is an advantage over a HERMS system as you don’t need to make changes to your HLT temperature on your brew day. The downside however, is this system is less efficient than HERMS.

 

The Pros and Cons of Electric Brewing and Mash Control

If you opt for an electric system and step mashing, having a form of fine control is advised. You’ll want temperature probes in the thermo-wells inside your various tanks.

Proportional integral derivative controllers (PID’s) are needed to set the target temperature of your mash tun and HLT. Having solid state relays (SSR’s) allows you to control the percentage output of electrical elements as well.

Also, with a HERMS system when heating your mash, please keep your HLT pump on to avoid temperature stratification in the tank. If you’ve variable speed control for your pumps it’ll help even more.

 

Electric Brewing – The Kettle

When boiling your wort in the kettle, a good target is 5 to 10% evaporation rate per hour. You’ll want temperature control for your kettle as well to avoid dangerous boil overs.

A proper understanding of the input energy needed to reach boil and achieve your desired evaporation rate can allow you to program a control panel. So, allow you to reach your targets batch after batch for better consistency. Let’s take a closer look at input energy (wattage) for further clarification.

 

Electric Brewing Wattage

The heat applied in your kettle is dependent in the overall wattage of your elements. In brewing the standard elements are ultra-low density and between 5,500 and 10,000 watts. Ultra-low means density means their configured to produce less heat per square inch.

Depending on the size of your brewhouse, you will have anywhere between 1 and 6 elements in your kettle. As a rough guide you need about 40-45 watts per liter of wort in your kettle for appropriate heating. Please note: there are 1000 watts in a kW.

The size of equipment you choose, determines wattage you must draw so, you need to check if your chosen site can handle those requirements.

 

Electrical Costings

It can soon get expensive if you need to upgrade your electrics to achieve a higher output. You also need to check if one or three phases is needed, plus what voltage too.

You need to think about the all the equipment which may be used at the same time. If you’re a brewpub you might have a kitchen running, a boil in the kettle, the HLT heating and a cold room running. What’s your total load and can your system keep up?

Breweries up to 3.5 US barrels (around 400 liters) will work with either single or three-phase, 208 or 240 service and require 60 to 100 amps.

When you move up to the 7 to 10-barrel range (820 to 1,170 liters), you’ll need three-phase 208 service and 200 amps of power available. You can go above 10-barrels for electric heating but it’s not usually recommended as the power drawn needed is high.

The price of electricity can vary from place to place so, I comment on costings on your region. However, please check if there’s a “peak time” charge in your area which may increase costs considerably.

 

Start-Up Costs of Electric Brewing

The price of tanks for an electric brewhouse are on the lower end. They’re certainly cheaper than steam which require extra jacketing. Plus, the costings for elements are cheaper than a burner (direct fire) and a fraction of the cost of a steam generator.

The cost for your control panel for your electric system depends on the system you order. If you opt for a simple system, with LCD readouts and manual push buttons the price will less that with a programmable touch screen.

Overall, the price for an electric system is going to be cheaper than for both direct fire (in general) and steam when heating your brewery.

 

Building Codes and Local Regulations

If you choose to have your brewery in a built-up or residential area, then electric could be right option. There’ll likely be more local regulations and building codes in place when it comes to the use of direct fire and steam.

Direct fire (open flame) and steam (the actual steam generator), could require the need for permits, venting, fire suppression, limits on size and/or inspections before installation and going online.

Depending on your location, with electric the one and only issue might simply be proper venting of steam during the brewing process for local authorities.

 

Electric – Safety and Environmental Concerns

When using electric, there’s less risk of fire than with a direct “fire” system as there no open flame. Furthermore, as long as the systems has been installed correctly with proper wiring and grounding there’s little chance of electric shock.

In the summer direct fire can be a nightmare. Direct fire is inefficient, as it heats up the air around the kettle as well as the wort itself. Electric has better heat transfer with elements immersed in the wort, so not heating up your brewing area as well.

Direct isn’t just hot it can be noisy too; overall electric is more “comfortable” than direct fire to brew with.

 

Electric Brewing Conclusions

Electric brewing is an attractive solution for aspiring brewery owners because:

  • The equipment is cheaper
  • Set-up cost are less
  • The path to opening is easier, where local regulations and building codes are concerned
  • Heat transfer is higher as the elements are immersed in the liquid

The disadvantages are, electric generally more expensive to run than direct fire and steam plus, you might have to pay even more at “peak” times. If you’re looking at bigger system then, you’re building might not be able to supply the electric demand needed.

If you’re on the smaller side say around 3.5 US barrels (around 400 liters), I’d seriously consider electric, as most buildings can support the electrical needs. Also, with a smaller system, it might be for a brewpub, where the use of space is at a premium.

In this situation electric makes sense, because it’ll take up less room that steam or direct fire as you don’t need a firebox or boiler/generator

When you go above 10 US barrels (around 1,200 liters), electric becomes less attractive as power needed becomes significantly higher.  One last issue we’ve not covered is the potential for “scorching”.

In the past brewers have been concerned about localized heating around the elements when boiling wort “scorching” or caramelizing the liquid. As technology improves and ultra-low-density elements have get better, it’s becoming less of an issue, but still worth highlighting.

Thanks for reading the first in our series on brewery heating solutions, we’ve direct fire and steam coming up shortly. Please subscribe to get first access.

 

Written by Neil Playfoot

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