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