While traditional brewers have relied on air circulation to cool their wort, modern breweries now use heat exchangers. This allows for year-round brewing, as hot days are not conducive to efficient cooling. Additionally, using heat exchangers reduces the introduction of bacteria and yeast from the air into the brew, preventing the buildup of dimethyl sulfide and its undesirable “cooked vegetable” taste, which can occur during prolonged cooling. However, the primary advantage of using a heat exchanger is that it significantly speeds up the brewing process.
If you are familiar with brewing, you have probably heard of counterflow heat exchangers or counterflow chillers. These types of wort chillers are the most efficient way to cool your batch without requiring massive refrigeration units. It’s important for any aspiring brewer to understand how they work!
A counterflow chiller is a type of heat exchanger that runs the cold liquid in the opposite direction of the wort.
This design allows the wort to flow through the heat exchanger in the opposite direction of the cold liquid. As the hot wort enters one side of the counterflow chiller, it transfers its heat to the copper pipes surrounding it, which then transfer the heat to the water flowing in the opposite direction. By the time the water reaches the end of the chiller, it has absorbed a significant amount of heat from the wort, although it is still cooler than the wort. As the wort continues to flow through the chiller, the water in the surrounding pipes gradually cools down until it reaches the original water temperature. In theory, an infinitely long chiller could cool the wort to the same temperature as the water being used.
However, when dealing with large quantities of beer, this type of wort chiller is not sufficient. You need something more efficient and easier to clean. Luckily, the same principles can be applied on a larger scale using…
Plate Heat Exchanger
The plate heat exchanger is perhaps the most popular type of heat exchanger found in breweries. It is highly efficient and compact, making it ideal for liquid-to-liquid applications such as chilling wort. The only limitation is that it cannot handle varying pressures between the plates, which makes it less suitable for condensation or other industrial applications.
How does a plate heat exchanger work?
Similar to a counterflow chiller, a plate heat exchanger involves running hot wort through one pipe and cold liquor (usually water) through the other in a counterflow arrangement. This causes the wort to flow down one side of the plate while the water flows up the other side (or vice versa).
Corrugated plates are used to increase the overall surface area of contact between the fluids and the plates. This, in turn, increases the heat transfer efficiency. The plates can be stacked to extend the contact time between the cold liquor and the wort, further enhancing the cooling process.