HEATING OPTIONS PART 3 – STEAM BREWING SYSTEM

Steam Brewing System Pros and Cons

Today’s article on the pros and cons of using a steam brewing system will complete our look at the three main brewery heating options. We’ve already looked at brewing with electric and direct fire brewing, once we’ve covered steam today, we can draw some conclusions in our final round-up article.

As we’ve mentioned in our previous heating articles, steam is a popular choice for brewers, especially on systems of 11.75 HL (10 US Bbl.) and up. A typical steam brewing system uses jackets on brewhouse vessels, as it’s the easiest plus cheapest way to implement steam heating.

Steam Jackets

To get a better understanding take a look at the picture below:

In the drawing opposite, there are two steam jackets on this kettle. The bottom jacket has steam going in N3 and coming out N2. Whilst the second jacket for the side walls has the steam going in N5 and coming out of N4.

The steam continually passes through these two jackets heating up the wort in the kettle. Having a jacket on the bottom allows a brewer to begin heating the wort as the kettle is filling from the mash/lauter tun. Saving some time during the brew day.

In most brewhouses you’ve the ability to regulate the flow of steam going into a vessel, similar to controlling a gas flame on a stove top. With a steam brewing system there are three alternate methods you can employ to heat your brewhouse, we will look at internal calandrias first.

Internal Calandrias – Steam Brewing System

Please note, when using an internal calandria your brew kettle will most likely have jackets too. So, you can heat up the wort whilst it’s filling like with steam jackets. There are several reasons why a brewer might opt for an internal calandria:

  • Increase the evaporation rate during boil – this can lead to shorter boil times.
  • Research suggest you see increased hop utilization and hop break – need to do some further research to confirm this.
  • Lowers the likelihood of DMS in your final beer – due to the vigorous boil and evaporation rates.
  • Lowers the incidence of caramelization in the kettle – when compared to some other systems due to wort movement.
  • Increases movement in the wort kettle – which can mean less energy input needed.
  • Shortens the brew day – it’s more efficient than steam jackets alone.

When using a calandria, the efficiencies come from the large amount of heating area they represent; combined with a small amount of heat loss to the atmosphere. The increased boil off rate is accounted for by greater heating efficiencies as well as increased wort movement.

Picture heating a pan of water on a stove top, the water will heat up and evaporate quicker if you’re stirring the pot. The act of stirring increases the surface area of the water in contact with atmosphere thus more water molecules escape as steam.

The increased efficiencies and possibility of shorter boil times means over time an internal calandria can pay for itself. They’re often used in larger breweries doing multiple brews per day, as the energy and labor savings make economic sense.

How Do Internal Calandrias Work?

An internal calandria stands vertical inside a brew kettle, using convection currents which forces the wort through the tubes inside the calandria where its super-heated by steam.

There aren’t any moving parts in a calandria, it’s works through convection (heat rising). Like in jackets, the steam can be controlled. It has a wort spreader (see the drawing above) which prevents boilovers plus promotes wort movement.

Note: Brewers tend to tun off the side jackets (and potentially the bottom ones too) of the kettle when boiling as it can affect the agitation of the wort.

External Calandrias – Steam Brewing System

External calandrias are mostly used in larger breweries as they are expensive. However, I’ve heard of breweries as small as 500-liters (4.2 US barrels) incorporate them.

The reason breweries pay the extra money for an external calandria is greater control of boil off rates as compared to internal calandrias. The speed of the pump can be controlled thus agitation from batch-to-batch can be replicated.

Furthermore, the steam rate to your EWB (external wort boiler) can also be adjusted too. If you look at the drawing above you can see the heating takes place outside the kettle.

The wort is pumped through the EWB, super-heated then returned to the kettle onto a spreader plate/cone which is just above the surface of the wort. The wort is pumped at a rate of 8 to 10 times the volume of the kettle per hour.

Unlike an internal calandria there are moving parts with an external one. This means there’s more which can go wrong, and some maintenance required. The extra piping, valves and pump needed also increases the start-up costs as well.

Steam Coil in Kettle

This method was used at the first brewery I worked at in the UK. Although, it’s not so common to see a steam coil in the brew kettle these days.

In fact, when I was looking for a picture of a steam coil used in a kettle, I had a hard time finding one. The coil below is actually for use in a hot liquor tank.

The main benefit of a coil is the heat transfer efficiency is high, as the “heating coil” is immersed in the liquid itself. They are hard to clean though (speaking from personal experience). In my first job I had to get inside and clean the coil by hand.

So, when it comes to steam brewing systems, there are really 3 main options and an “outmoded” option.

  • Internal calandria
  • External calandria
  • Steam jacket
  • Steam coil (rarely used)

In a HLT (hot liquor tank) a coil makes sense, it’s water and so doesn’t need regular cleaning. Most breweries might clean the HLT with a regular acid CIP once every one or two months and have scheduled passivation.

You’re not looking for a vigorous boil just getting the water to temp, usually around 77-80°C. If properly designed a HLT should heat up by 1°C per minute when full.

Steam Brewing System – Mashing In

The mash mixer/tun depending on your system will use steam jacket to heat up the mash, similar to the brew kettle we explained earlier.

There’s an agitator or paddle inside the vessel to mix the mash, like the one in the picture below on a 25HL (21.3 US barrel system) to ensure a homogenous mix and even heating.

In smaller breweries sometimes the mash is mixed by hand with handheld mash paddle. It’s always great exercise to the get the blood flowing at the start of a brew day.

Brewery equipment manufacturers calculate the design of brewhouse vessels to heat up liquid (wort/water) 1°C per minute, it’s the same for mash tuns/mixers too. Having the ability to heat your mash is preferred as it allow you to step mash.

For some styles of beers like Hefeweizen for example, being able to mash in at a lower temperature, say 50°C for a protein rest can help guard against a “stuck mash”.

Step Mashing

When you step mash, you raise the temperature of the mash over the course of the mash stand. It helps brew beer to style, say if you’re making a sweet stout.

You might want part of you mash stand to be at a higher temperature so you’ve some “unfermentables” in your final beer for residual sweetness. I like to be able to step mash for my lagers, wheat and some ales too.

One more thing: Seems a good idea to explain here, if you’ve a separate mash and lauter tun. The lauter tun doesn’t usually have a steam jacket. You heat up the mash in the mash mixer to say 78°C for “mash out”.

Whilst you’re heating the mash you pre-heat the lauter tun and leave enough hot water in the vessel to cover the lauter plates/screen. The lauter tun will be well insulated so you’ll not see much drop in lauter temperature during the lauter rest and vorlauf.

The vorlauf is when you recirculate the wort out of the bottom of the lauter tun back into the side of the lauter. To clear it (using the mash bed as a filter), prior to sending the wort o the kettle.

The Advantages of a Steam Brewing System

As we said earlier steam is popular with breweries for a number of reasons. Yes, it the most expensive to purchase and install but for many it’s worth the cost.

Steam Has Many Uses in a Brewery

The one big plus is how versatile steam is for use in a brewery. For example:

CIP Unit Heating – As part of your CIP unit you need to heat your caustic and hot water, this is easier and more efficient with steam.

Cask/Keg Cleaning – Many keg/cask cleaners use steam as part of the cleaning/sterilizing process. You can get options without steam, but it’s better if you can utilize steam.

Sterilizing air for wort aeration – many breweries use pure O2 for aerating their wort, ordering oxygen bottles from an outside company. If you have an air compressor in your brewhouse you can use that to aerate wort.

Air from the compressor isn’t clean, but you can use steam to “sterilize” the air making it suitable for wort aeration. Even if you don’t like the idea, it’s nice to have the backup in case of emergencies.

Cleaning barrels – If you’ve a barrel program, steam is great for cleaning those barrels.

That’s just a few uses of steam I can think of, I’m sure there are more. When I think of them, I will add them later. Anyway, as you can see having steam in your brewery is rather handy.

Other Advantages of Steam

Faster Temperature Increase

When you utilize steam in your brewhouse you’ve a large heating surface area, whichever method you employ. It means you’re able to heat your wort quickly, maintain a vigorous boil and have good evaporation rates.

Even Distribution of Heat

Having a large surface area for heating leads to more even heat distribution. Meaning you’ve less chance of scorching or sticking during your brew day. Furthermore, less sticking as compared to direct fire or electric makes cleaning up easier too.

Versatility

As we said before steam has so many uses in a brewery from cleaning kegs to compressed air for wort aeration.

Control

If you use the right equipment manufacturer when sourcing your brewhouse. Plus, the system is designed well, steam is easy to control in the brewhouse. Having finer control allows a brewer to more easily replicate procedures and produce a more consistent product.

The last brewery I set up had a touchscreen where I could control the steam valve open rate as a percentage. It’s nice figure to have and record it on your brewsheet for historical data over time.

Expandable and Long Lasting

We said earlier steam is expensive to install, it’s also more work to maintain too. However, a well-looked after steam generator where preventive maintenance is carried out can last a long time and provide a sound investment.

Also, quite popular with Chinese equipment manufacturers is the use of electric steam generators. These generators can be run in sequence. So, if you expand and need more steam, your brewery you can run the original steam generator alongside a new one thus minimizing the cost of expansion.

Disadvantages of Steam Brewing System

More Expensive

Yes, I’ll say it one more time the cost of installing a steam boiler/generator is higher than direct fire of electric. Then there’s regular work needed to maintain the equipment. You need to keep an eye in the water treatment feeding the boiler and backflush your coils on a regular basis too.

More Regulated

You’ll need to check with your local authorities about the use of steam at you chosen location. In some places steam might not be allowed or there might be a cap in the size of steam boiler/generator you can have. Then local emission regulations could significantly increase installation costs and reduce efficiencies as well.

Cost Effectiveness

If you’re start a small (under 300 litres) brewery, taking into account start-up costs of steam and maintenance involved, it might not be worth it. If you really want to steam then go with an electric steam generator.

Steam Brewing System - Conclusions

As a brewer who has worked on many different systems over the years, I’m a fan of steam personally. I wouldn’t consider any other heating method in a brewery bigger than 15HL (12.8 US barrels).

For a larger brewhouse, the greater control, versatility and heating speed of a well-designed brewhouse as well as ease of clean-up, make it an easy choice for me. When using steam, I can be heating my HLT, mash tun and kettle all at the same time. When doing multiple brews per day it all helps.

The up-front costs are paid back in cheaper heating plus, time saved during a normal brew day and through labour costs as well. Steam is versatile and makes a brewer’s life easier too.

 

Written by Neil Playfoot

 

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.