Lesson 4 - Clarification – Centrifugation
This lesson discusses beer clarification via centrifugation. Clarification removes yeast and solid particles from the beer in order to make it ‘bright’ or reduce the amount of haze. Centrifugation is one method that we can use to clarify beer. This lesson looks closely at the physics of centrifugation and the concept of accelerated gravitational force. By the end of the lesson, you should understand the importance of this process and its impact on final beer quality.
Preface
In this lesson, we will consider the importance of centrifugation, the benefits that it has for beer quality, and how it is important that we plan this process so that it meets the brewery’s needs.
Not all beer styles require the beer to be ‘bright’. However, for those styles that do, we will need to clarify the beer.
‘Bright beer’ is a term used to describe beer that allows the consumer to read large print through the glass of beer when the printed paper is held behind the glass.
There are degrees of brightness, from ‘brilliant’ (no visible particles in the beer), ‘bright’ (beer is very clear), ‘hazy’ (slight cloudiness, but still fairly clear) and ‘cloudy’ (beer is difficult to see through).
We will start with the main objective of clarification. Clarification is the removal of unwanted beer components at the end of the fermentation and maturation process, these components include:
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Suspended yeast
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Cold break (sedimented protein and polyphenol haze forming material)
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Spent hop material
Removing these beer components brings a number of quality (flavour and colloidal stability) and process efficiency (such as filter run lengths) benefits. We will cover these in more detail in the Filtration lesson, as well as in the Beer Properties unit. So, where in the process should we use the centrifuge? We will look at this on the next page.