Lesson 4 - Wort Boiling Technology and Process Control

The brewhouse is the single biggest user of energy in the brewery. And wort boiling is the most energy intensive activity undertaken in the brewhouse. The equipment we have discussed so far helps reduce the energy used in the boil but to ensure that it is minimised we need a more wholistic approach.

Reducing the energy that you use to boil

Before we get on to systems that can ensure energy use is minimised it’s important not to overlook opportunities to save energy by adapting the process. There are several things that we can do to reduce the energy added to the boil that don’t require changes in equipment. These are:

• Add liquid adjuncts in whirlpool (less mass/volume to heat).
• High gravity brewing (less volume to boil means less energy used).
• Reduce target evaporation (while ensuring the objectives of wort boiling are achieved). 4% is a target used in most modern brewhouses.
• Coordinate brewhouse activities to ensure that any energy recovered from boiling can be used as soon as possible and prevent the need to heat cold vessels and boiler water. For example, if you need to brew 7 times per week, do this over two days rather than one brew per day.
• Maintain a stable and consistent brewing programme. Brewhouses that save energy are designed to produce brews within specific parameters. Continually varying brew size, gravity, boiling programmes and cooling temperatures is likely to lead to wasted energy because what is recovered from one brew may not be used in subsequent brews.

The Technical Summary of the functions of wort boiling by Tim O’Rourke gives a good summary the reasons for boiling wort.