Was just speaking with a guy about his brewing project in Australia, he asked “do I need a cold liquor tank for my brewery”? Well, his enquiry was more like this…
I thought this was a great question so, I wanted to make a short article about it.
There are several factors to consider, which are:
- What is the average mains water temperature and pressure at the location?
- What type of beers will be made mostly?
- How many brews per day will be done?
- How many cellar tanks and overall volumes will the glycol system be cooling?
- The size of the brewhouse
- The floor space allocated to the brewing facility
- Overall budget for the brewery project
The Different Types of Heat Exchanger
There are other factors, but these are the main ones. I’ll be up-front, where possible I’d always opt for to have a CLT. I’m old school this way.
However, many smaller craft breweries these days use a two-stage heat exchanger. A two-stage heat exchanger uses both mains water and glycol.
The mains water cools the wort down, coming directly out of the brew kettle/whirlpool. The glycol system then brings the wort temperature down the rest of the way. To the temperature needed for fermentation.
One Stage Heat Exchanger – Do I Need a Cold Liquor Tank (CLT) For My Brewery?
Now, a one stage heat exchanger uses cold water only, to cool the wort down from the kettle. The system requires a cold liquor tank (CLT).
The CLT as a rule, is generally twice the size of the brewhouse. For example, if a brewery has a 500-liter brewhouse (4.2 US beer barrels), they’d have a 1,000-liter CLT (8.5 US beer barrels). However, a CLT can be bigger, if needed.
When collecting wort to a fermentation tank. The cold water in the CLT chills the wort all the way down to the fermentation temperature.
When using a CLT, ideally the tank should be filled 24 to 48 hours before it’s needed. This gives the glycol system, time to cool the water down.
Cooling a Cold Liquor Tank
Typically, most CLT’s can be cooled to the correct temperature in 12 hours or less. However, giving more time, only helps ensure the water is truly cold in the CLT.
For example, when I used to brew in Bermuda, at the height of summer the ambient temperature of the water was high. Sometimes 30°C + (86°F).
Furthermore, the whole glycol system was working harder to keep the beer maturing in the tanks, cold enough.
Giving the glycol extra time to cool the water in the CLT down, was always my standard operating procedure. Also, sizing your glycol system, correctly is key to having an efficient brewery.
Anyway, let’s look a little deeper into some of the factors, used to decide what type of heat exchanger is needed for a brewery.
Water Temperature and Pressure – Do I Need a Cold Liquor Tank (CLT) For My Brewery?
In previous articles, like this one I’ve spoken about water pressure. Ideal water pressure for a brewery is 60 Psi (4.1 Bar) and above with flow of at least 100-liters (0.85 US beer barrels) per minute.
I’ve worked in some breweries, like a brewpub in Paris, where the pressure and flow rate were much lower. This made wort collection painful, it took more than an hour.
When the water temperature in the summer reached 28°C (82.4°F) +, collection times were even longer. If we’d had a CLT, the length of the brew days would have considerably lower.
If the mains water temperature and pressure aren’t up to par, it means the glycol is working harder, when using a two-stage heat exchanger.
In the summer months over-extending you glycol system can lead to issues with keeping you cellar tanks cool too.
There are Two Options
The two options to have the neccassary cooling capacityt are:
- Get a glycol system rated higher
- Or go with a one stage heat exchanger and a cold liquor tank
Having a cold liquor tank, means the temperature of the cooling water is constant (usually around 2°C [35.6°F]).
Making a brew day more predictable, when compared to changeable mains water temperature.
Additionally, as the CLT water is pumped to the heat exchanger, the pressure will be known and constant too. You can even regulate the water pressure with a valve as needed. Mains water pressure can drop (be unpredictable), when there is a big demand for water. Which can be often in the summer months, so making wort collection even more of a challenge.
What Type of Beers Will Be Brewed Mostly?
If a brewery is mostly brewing lagers, then the collection temperature of the wort needs to be colder than for ales. Lager fermentation temperatures are typically around 8 to 14°C (46.4 to 57.2°F).
Ales are typically fermented at anything from 18 to 42°C (64.4 – 107.6°F). Kveik yeasts can be fermented at very high temperatures.
So, if a brewery is making mostly ales, then wort cooling is easier, as the temperature of wort collection can be higher.
This means, having a two-stage heat exchanger is a more viable option. As the glycol system will not have to work as hard.
However, if a brewery is mainly making mainly lagers, then having a CLT becomes more appealing. So, irrespective of the conditions, a brewer knows they can collect the wort in a timely manner.
How Many Brew (Turns) Will There Be Per Day – Do I Need a Cold Liquor Tank (CLT) For My Brewery?
Now this site is mostly for smaller craft breweries, those which will at most, brew twice per day. If you plan to brew more once a day, then a CLT becomes a more attractive option.
Collecting wort with a two-stage heat exchanger heats up the glycol. The glycol system will have to work hard, to be ready to collect wort of the second brew.
If you’ve CLT, it should be sized to deal with the volume of wort planned to be brewed in one day. You can have a double, triple or even larger sized cold liquor tank.
Furthermore, with a single-stage heat exchanger, you’re only using water to cool the wort. This cold water becomes hot after the heat exchanger, and is directed back into the HLT (hot liquor tank).
When doing more than one brew per day, this extra hot water comes in handy for the next brews. Plus, is also great for cleaning, after the brew day is finished too.
Size/Volume of the Cellar Tanks – Do I Need a Cold Liquor Tank (CLT) For My Brewery?
If you have a brewery with a lot of cellar tanks. For instance, I know of one 2,000-liter (17 US beer barrels) brewery in China, with 65 x 2,000-liter fermentation vessels.
They produce a lot of different beers for the market. With such a large cellar volume. You’ll have a very large glycol system, compared to comparative size of the brewhouse.
In this case, cooling of wort using a two-stage heat exchanger will not really put too much pressure on the glycol. This is a very are instance, but worth noting anyway.
The Size of the Brewhouse
If you have a very small brewhouse say 300-liter or below. Then nine times out of ten it makes sense to go with a two-stage heat exchanger. Unless the water pressure is really poor.
Side note: If water pressure is really poor, then consider another location for the brewery. Otherwise, you need to find a solution to increase water pressure on site. Poor water pressure really makes a brewer’s life miserable.
Some people would say anything under 500-liters (4.2 US beer barrels) would be fine, as long as water pressure and temperature was acceptable for a two-stage heat exchanger.
At the height of summer, a brewery might have to turn cooling off, on the beers on chill, in the cellar for a while. However, most modern cellar tanks are well insulated.
So, the temperature of the beer shouldn’t go up much. Not enough to harm the beer or concern the brewing team. Beer being left without chilling isn’t ideal, but still within acceptable parameters in most instances. Also, when it comes to smaller breweries, the next factor also needs to be considered as well.
How Much Space Is Allocated for Brewing – Do I Need a Cold Liquor Tank (CLT) For My Brewery?
In smaller breweries, which are most likely brewpubs. The smaller the footprint of the production facility the better.
As there’s most likely also a kitchen, toilets, a cold room needed plus, a brewery wants as much space available for customer seating as possible.
Any saving on space is to be considered. So, having a larger glycol system allowing for a two-stage heat exchanger, using glycol makes sense.
It’ll take up much less room than having a dedicated CLT. If you have outside space, then a cold liquor tank can live outside. Make sure it’s in shade though.
I used to brew in Bermuda, we had a double sized CLT, which lived outside. We had no issues with cooling down wort, even when brewing two-batches of lager in a single day.
However, most brewpubs don’t have outside space to place tanks. Therefore, a two-stage heat exchanger makes the most sense.
Using as little space for beer production as possible, makes the most sense for a brew pub.
The Overall Budget of a Brewery Project
If the budget for a brewery is tight, then there’s a need for “bang for your buck”. In this instance, a two-stage heat exchanger wins out every time.
It’ll always be the cheaper option to get a bigger glycol system, than having an extra tank, pump and additional hard piping for a CLT.
Conclusions – Do I Need a Cold Liquor Tank (CLT) For My Brewery?
As you can see, when it comes to the question “do I need a cold liquor tank for my brewery”? There’s a lot to consider; from beers being brewed, to size of the brewhouse.
If the facility is a brewpub of 500-liters or under, then most likely a two-stage heat exchanger is the right option.
In lager facilities, like the brewery I worked for, in Armenia. Which was a 3,500-liters brewhouse. Which we brewed on twice a day, most brew days. Having a CLT made sense, especially as we were mostly brewing lager.
I’m old school preferring to having a CLT, if budget and space allows. Also, I like working with constants, having a CLT means I know water temperature and pressure at all times.
Also, if for any reason, the mains water gets cut. I can still ensure the wort ends up in the fermenter every time. If using a two-stage heat exchanger, having no mains water is an issue. Every situation is different and if you’re still unsure what’s the right option for you. Then feel free to reach out to me for assistance.
Do You Need Help with a Brewery Project?
As a brewing consultant originally from England (now based in China), I help people with their brewing projects. I’ve done a number of installs, during my 25-year+ brewing career.
I’m currently assisting on projects in Japan, The Philippines, Sweden and Australia. I can help people from mapping out the scope of their project, all the way to assisting with install.
Depending on the project and location of the brewery.
Most of my clients need help with sourcing equipment within their budget, which I can help with. Many people are now buying their brewing equipment from China.
As someone who first came to China in 2010, to brew, I know the market here, well. Allowing me to ably assist with sourcing brewing equipment. Plus, I can do equipment inspections on a client’s behalf as well.
So, if you need assistance on an upcoming brewery project, then please feel free to get in touch. My email address is:
Or you can message me directly on your preferred network. Simply scan the relevant QR code below, add me and message me directly.
I look forward to hearing about your project. For now, thanks for reading and have a great day.