Cold Liquid Tank To Cool Wort

Understanding and mastering the nuances of each step in the beer brewing process is crucial. One of the key steps in the brewing process is cooling the boiling wort. This is a crucial process, as rapid cooling of the wort can affect the flavor, aroma, and quality of the finished beer. Today's article is about the cold liquor tank (CLT) used to cool the wort.

What is a Cold Liquid Tank (CLT)?

A CLT, short for Cold Liquid Tank, is a specialized container used by breweries to cool and store water. Typically made of stainless steel, it is located near the brewery, close to the heat exchanger.

A cold liquid tank has a welded cooling jacket, meaning it consists of an inner and outer shell with insulation between them. A coil of tubing runs between the two shells, allowing glycol from the cooling system to flow through, cooling the water in the tank to the desired temperature.

The water can be cooled to a temperature of approximately 1°C to 7°C, depending on the beer being brewed. Water from the CLT is pumped through a heat exchanger to cool the wort entering the FV. As the cold water flows through one side of the heat exchanger, the hot wort flows through the other, causing the liquid to flash cool. This means it is instantly cooled to the temperature required for fermentation. The water does not come into contact with the beer but instead enters the hot liquor tank (HLT). This cold water "draws away" the heat from the beer, making it even hotter itself. The resulting hot water can be used for the next brew or to clean brewing equipment.

Benefits of Cooling Wort with CLT

Maintaining the Required Water Temperature

When using city/tap water to cool wort, the water temperature may be affected by year-round temperature fluctuations. In the summer, tap water temperatures can be 12-20°C higher than at other times of the year. For beer (even ale), regulating the wort to the desired temperature can be challenging. This means the glycol in the two-stage temperature exchanger works harder, resulting in a higher glycol temperature at the end of the wort collection. Furthermore, you may need to shut down heat exchangers that are stored at lower temperatures, as these too may heat up.

Also, note that ambient temperatures are higher in the summer, and the entire glycol system must work harder to return the glycol temperature to normal operating levels. In the summer, the higher ambient temperatures put the glycol system under significant strain, already working overtime.

Prepare extra warm water for the next cleaning or brew.

Cooling wort with cold water generates plenty of hot water for the next brew or cleaning. For example, I clean the kegs the day after brewing, providing ample hot water. Furthermore, if you decide to do a full-scale caustic brew the next day, you'll have plenty of hot water to complete the process. The best way to use a single-stage tank is for continuous brewing. Note that the hot water from the wort collection can be used for the next brew.

Reduce the workload on the glycol system

Using a single-stage cold water heat exchanger means you don't need to use glycol to cool the wort. This reduces the glycol system's operating load and eliminates the need to shut down the cooling system on the cellar tanks it's already cooling. Another advantage is that the same size glycol system can now cool more cellar tanks. This allows you to add more cellar tanks during installation or later as you expand.

Disadvantages of using CLT to cool wort

Dedicated CLTs incur additional costs for piping and controls, and there are also fees for connecting the tank to a glycol cooling system. However, boiling water is expensive. Over time, you can recoup the initial cost, and the recovered hot water can be used for other purposes. If you're brewing, each brew provides hot water for the next.

Space

CLTs take up more space. If you run a brewhouse, space is at a premium. If using a CLT would take up space for one or two tables, it's not the best choice.

Planning

When using a CLT, you need to fill it and begin cooling it at least 24 hours before brewing. Lowering the temperature takes time.

If the water pressure is insufficient, it may take a while to fill the tank. Furthermore, once the tank is full, you may not be able to use the water for other purposes. This means you need to plan this step into your schedule.

How big a CLT should be?

This depends on the size of your brewery and the beer you brew. If you brew beer that ferments at a lower temperature than your ale, you'll need a larger CLT. Furthermore, if you're brewing multiple batches, a larger CLT is recommended. Manufacturers and brewing consultants recommend a CLT that's twice the brewing time. So, if you have a 1,000-liter brewery, a 2,000-liter CLT is recommended. This provides a buffer and also cools the wort for your beer. If your brewery brews several times a day, a CLT that's three times the brewing time is recommended. If you brew several times every 24 hours, you'll need additional fills throughout the brewing cycle.

Summary

If you have the space and budget for a CLT, I recommend it. It's well worth the money and makes planning and brewing much easier. Being able to use cold water for hot water is very useful, especially if you brew coffee multiple times a day. Most importantly, it means your glycol system has less work to do, reducing the strain on cooling the hot wort.