Now on to brewing with steam, the second option is our brewery heating series. Steam is a popular heating method in craft brewing, especially for brewhouses 10bbl (11.75HL) and over.
The first article in the brewery heating series was “Brewing with Electric“, please click the link to read it for yourself (opens in new tab).
In this article we will discuss why steam is the preferred method for many brewers. Starting with steam jackets, the preferred and easiest way to implement steam heating in a brewery.
Let’s look at the diagram of a brew kettle with steam jackets below, to get a closer look…
If you look in the diagram above, you will see two steam jackets. One is at the bottom, with the steam going in N3 and coming out at N2. The second jacket is on the side walls, with the steam going in N5 and coming out N4.
As the steam continuously passes through these jackets, it heats up the wort in the vessel. In most brewhouses you can regulate how much steam goes in the vessel, much like controlling a flame on a stove top.
There are three other methods you can employ to heat your brewhouse with steam, we’re going to begin with the internal calandria.
Brewing with Steam – Internal Calandria
A brew kettle with internal calandria usually has a bottom jacket too. Some reasons to add an internal calandria to your brew kettle are as follows:
- Shorten your brew day – As it more efficient heating than jacket alone
- Increase evaporation rate – So potentially shorter boil times depending on beer style
- Increase the movement of wort in the kettle – So, also potentially requiring less energy input
- Less chance of caramelization than some systems – Due to wort movement
- Reported increased hop utilization and hot break – I need to research this further to confirm
- Lowers the chance of DMS – Due to a vigorous boil and evaporation rates
A calandrias efficiencies comes from the large amount of heating area they represent combined with very little heat loss to the atmosphere. We can explain the improved boil off rate through by more efficient heating as well as increased wort movement too.
Think of heating a pan of water on a stove top, it’ll heat up and evaporate faster if you’re constantly stirring it. The agitation increases the surface area of the water in contact with the atmosphere allowing more water molecules to escape as steam.
The improved efficiencies, plus potentially shorter boil times for some beer styles means over time the calandria to pay for itself. Especially if you’re doing multiple brews per day, imagine the savings in energy and labor.
How Does an Internal Calandria Work?
You place a calandria vertically inside a brew kettle, it uses convection which forces the wort through the tubes inside the calandria where it’s super-heated by steam.
A calandria works without any moving parts but, instead through convection (heat rises). It’s controlled with steam regulation. It has a wort spreader (see fig.1 above) to prevent boilovers and as well as promote wort movement.
Note: When using an internal calandria, turn off the side jackets when you’re boiling, because if you have them on (and potentially the bottom ones too), it can affect the agitation of the wort.
Brewing with Steam – External Calandrias
External Calandrias are mostly used in larger breweries, although I’ve heard of them being used in small 500-liter (4.2bbl.), systems too. An external calandria offers the same benefits as an internal calandria.
However, external calandrias offer more control of boil off rates than internal calandrias. As the speed of the circulation pump can be regulated so, agitation from batch to batch can be replicated. Furthermore, steam flow to your EWB (external wort boiler) can be adjusted as well.
As you can see in the fig 2. Above, heating takes place outside the kettle. Wort is pumped through the EWB, super-heated and then returned to the kettle onto a spreader plate/cone just above the surface of the wort. The circulation is around 8 to 10 times the volume of wort in the kettle per hour.
The downside to an external calandria (compared to internal) is more moving parts so, there’s more which can go wrong, plus more maintenance required as well. Also, the extra piping, valves and pump, increase your start-up cost too.
Brewing with Steam – Coil Inside of the Brew Kettle
Now this isn’t a common set-up; however, the first brewery in London I worked for, had this system. These setups appear so rare, even when I Google “steam coils in a brew kettle” nothing comes up.
The above picture is for a HLT steam coil. The most obvious benefit is, the heat transfer (therefore efficiency) is high, as the “heating coil” is immersed in the liquid being heated.
They’re super hard to clean though. I used to have to get inside and clean the coil by hand. It was also always hot in there so, a damn good work out [laughing emoji]. So, really there are 3 main options and this “outdated” option.
- Steam jacket
- Internal Calandria
- External Calandria
- Steam Coil (less used)
In a HLT a coil makes more sense; it’s water and doesn’t need cleaning. Only for regular acid CIP (maybe every 2 months) and scheduled passivation. You’re not looking for a vigorous boil only to get it to temperature.
If designed right, a coil in the HLT can still raise he temperature by 1°C per minute. As the coils are immersed in the liquid, the heat transfer is still efficient.
Mashing in With Steam
When using steam in you mash tun or mash mixer (depends on your brewhouse setup), the vessel usually has steam jackets similar to the brew kettle. There’s an agitator or paddle inside the mash tun, to mix the grain and water and ensure a homogenous mix.
The steam jacket combined with agitation allows for efficient heating. Please see the picture below for a typical mash paddle in a mash mixer. This one is on a 25HL (21.3 bbl.) system.
In some smaller breweries this “mixing” is often done by hand with a manual mash paddle. It’s always a great way to start the day and get the blood flow pumping.
Brewhouse manufacturers design vessels to heat at 1°C per minute, including for mash tuns. Being able to heat your mash tun is better for your brewery, as it means you can step mash.
With step mashing, you raise the temperature of the mash over the course of the mash stand. This allows you to brew beer truer to style plus also helps with lauter run off to kettle, on some beers like Hefeweizen.
It seems pertinent to note here: If you’ve a dedicated lauter tun, it’s not usually jacketed. You raise them temperature of the mash to around 78°C in the mash tun.
You then send it to the preheated lauter tun. A properly insulated lauter shouldn’t drop in temperature during the lauter stand and vourlauf. Vorlauf is the recirculation of wort in the lauter tun to clear it, prior to transfer to the brew kettle.
Steam Can Be Used Elsewhere If You Employ It in Your Brewery
There are other advantages to having steam in your brewery. It can be used for other tasks including:
For heating your CIP unit – Granted many use electric heating instead, to heat the caustic.
Cask/Keg cleaning – Many keg cleaners use steam as a part of the process. Steam can be used as part of the sterilization step as well as for heating the caustic
Sterilizing the air for wort aeration – Most brewers used pure oxygen to aerate their wort on the way to the fermenter. However, you can also use air from your compressor.
However, it’s not going to be “clean”. You can use steam to “clean” the compressed air, making it suitable for wort aeration. Even if you don’t like this idea, it’s still a good back up to have just in case.
Cleaning wooden barrels – If you’ve a barrel program, steam is useful to clean them.
I’m sure there are other uses for steam I’m missing out on; I will add them later, if I think of them. However, as you can see steam definitely has it uses around the brewery.
The Advantages of Brewing with Steam
As we said at the start of the article, most brewers prefer steam for some of the following reasons:
Fast Temperature Increase
When using steam, the “heating surface area” is large, with both bottom and side jackets plus optional calandria. So, it’s possible to heat your wort quickly and maintain a vigorous boil for good evaporation rates.
Even Heat Distribution
The large surface area leads to more even heat distribution, so there’s less chance of scorching/sticking. Furthermore, it’s easier to clean up after, than using direct fire or electric when the brewing is finished.
As we said above you can you use steam for a number of tasks in a brewery from cleaning kegs to cleaning compressed air for wort aeration.
Depending on your brewhouse set up, steam can be easy to control, making procedures and processes simpler to replicate. The last brewery I installed, allowed you to open the steam valves as a percentage, meaning fine control of the boil.
Long Life and Potentially Expandable
In the disadvantages list of using steam below, I say how steam requires more maintenance. However, if you properly maintain your boiler and perform preventative maintenance, a boiler can last a long time, providing a sound investment.
Also, if you use an electric steam generator they can be run in sequence. So, if you expand and require more steam, you can buy another electric steam generator to run alongside your original one. So, the costs of expansion are minimized.
Disadvantages of Brewing with Steam
The upfront costs of installing a boiler are high. They also require a fair amount of maintenance to keep the generator in top shape. From keeping an eye on the water treatment feeding the boiler to making sure you regularly clean the internal coils (usually by back flushing them).
Depending on where your brewery is, local regulations might not allow you, to house a boiler in your brewery. Before you opt for steam make sure you’re allowed it in your location. Local emission regulations can significantly increase costs and reduce efficiencies too.
For a small brewhouse, steam might not be cost effective when you consider start-up costs, needs for the brewery and maintenance. On a smaller system, an electric steam generator is probably the way to go if you really want steam.
Brewing with Steam Conclusions
I am a fan of brewing with steam myself. I’ve used it in a number of systems I’ve worked on. I wouldn’t consider anything else, in brewhouses over 15HL (12.8 bbl.) in size.
In the larger brewhouse; the control, versatility, speed of heating, if the setup is right, PLUS ease of cleanup make it a no brainer for me.
I can potentially be heating a hot liquor tank (HLT), mash tun and wort in a kettle as it’s filling up, using steam all at the same time. If I have a 3, 4 or 5 vessel system doing multiple brews per day.
Therefore the upfront costs are paid back in cheaper heating plus saved time and labor costs.
On Smaller Systems
On a smaller system the choice isn’t so clear. However, this is a 4 parts series on brewery heating methods. So, to give proper consideration to all heating methods and brewhouse set-ups it makes sense to draw conclusions in the final part.
The final part released, after the direct fire article. Which will be a little different because I’m bringing in some experts to collaborate with. As, they’ve got a cool direct fire option I want to share with you, as well as a host of other great information.
Please follow me on social media if you want access to the final part as soon as it is ready. As I will be posting links to it, on those platforms.
Who Am I?
Hello, my name is Neil, I’ a British brewer based in China. I first came to China in 2010. I’ve been lucky enough to have brew on a number of systems, in various parts of the world in my 25-year brewing career.
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Thanks for taking the time to read my article today, I hope you found it useful. Have a great day and happy brewing.