Lesson 2 - Steam Theory
This lesson introduces steam as a heating medium. It outlines its uses, benefits, and various properties. It also explains the difference between utility and culinary (clean) steam, as well as the production methods employed for both.
Preface
Steam is used as a heating source in many places within the brewery. As we will see in this lesson, steam contains high amounts of energy in the form of heat. Steam is also an efficient transporter of heat.
Steam is produced via a boiler system, and is carried to brewing equipment via a distribution system of pipes. When steam finally reaches the equipment, it is condensed, and the heat is transferred.
Steam has many uses in the brewery:
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Steam-heated brewhouses have vessels with steam jackets, which allow transfer of the heat from steam to mash vessels and wort kettles.
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It is used in flash pasteurisation of beer prior to packaging.
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It is also common to use steam to sterilise equipment such as propagation tanks and heat exchangers. This process is called ‘steam sterilisation.’
We use steam for these types of applications for several reasons:
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It has a very high latent heat of vaporisation, at around 2,260 KJ Kg-1 at atmospheric pressure.
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The heat can be released at high temperatures, which is ideal for beer-related uses such as pasteurisation.
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It is relatively cheap to produce as its only main requirement is a clean water source.
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It can be easily distributed throughout the brewery.
The rest of this lesson will explain some of the physical properties of steam, and how we can use steam as a heating source.