Lesson 6 - Process Aids and Additions

The main reason to make colour adjustments to a beer is for quality and consistency.

We assume that consumers drink with their eyes and that a brewer may want their beer to be the same colour each time, every time. However, some brewers want their beers to be perceived as authentic. For product integrity reasons, they do not believe in adjusting colour. There is no right or wrong approach to this. Your brewing philosophy will determine your approach.

It is easy to calculate how to blend and achieve specific results:

Aa + Bb = Cc

A and B and C = volume

a and b and c = colour (or any attribute)

What is the resulting colour if I blend 20 hL of beer of 10.5 EBC with 35 hL of beer of 12.2 EBC?

(20 x 10.5) + (35 x 12.2) = (20 + 35) x c

210 + 427 = 55 c

c = 11.58 EBC

Or... I want to achieve a colour of 9.0 EBC. I have 100 hL of 8.0 EBC beer and some darker 10.5 EBC beer. What volume of the darker beer do I need to add to achieve the desired colour?

(100 x 8.0) + (V x 10.5) = (100 + V) x 9.0

800 + 10.5 V = 900 + 9 V

1.5 V = 100

V = 66  hL

A brewer may need to adjust colour due to colour variation amongst the malts in the recipe and the possible variation of colour formation during wort boiling. Some breweries may take a ‘safe’ approach and brew their brands to a colour slightly lower than target specification. They would then increase the colour post-fermentation.

The most commonly used ingredients for colour correction are:

• Caramel

• Coloured malt extract

• Roasted malt beer extract

Caramel

Caramel syrups are made by heating sucrose or starch solutions with ammonia at high temperatures. Caramels have a very high colour, around 50,000 °EBC and 65% solids. Therefore, the dose rate for minor colour adjustments is very small!

On the plus side, it is virtually free of flavour or aroma; this can be beneficial to the brewer. For example, if we use caramel to colour the beer after fermentation rather than using a large amount of dark malts in the brewhouse, we can produce a dark beer with a far less ‘roasted’ aroma and flavour.

However, there is one major issue to using caramel – it is regulated as a permitted food additive; only E150c should be used in beer. Caramel is an extensively used and permitted food colouring worldwide. However, recent concerns have been raised over caramel prepared with ammonia. Carbohydrates prepared with ammonia under high temperatures can produce a toxic by-product called 4-methylimidazole (4-MeI). Questions have been raised over 4-Mel’s link to convulsions and also its potentially carcinogenic properties. As these findings are linked to animal reactions only, this does not necessarily mean that humans will respond in similar ways. However, it does of course cause concern. So, how much of a risk is caramel? The Centre for Science in the Public Interest claims that ten teaspoons of obesity-causing sugars present a greater health risk than ammonia sulphite process caramel. A brewer typically doses very small quantities into their beer, so health risks are low. However, brewing companies are now actively seeking alternatives, in order to ‘do the right thing’ for their consumers.

Coloured malt extract

An alternative is derived from malt, whereby a malt extract or syrup is produced in the brewhouse. After lautering, the wort is vacuum evaporated to remove water and concentrate the wort, creating a pure malt extract.

The process can be adjusted to create a range of different products for colour or flavour adjustment. Process changes could include a change to the mashing profile to create a highly fermentable or sweet extract that can be used to add fermentable extract or one that has very low fermentability and primarily for colour. Different speciality malts can be used to create a full range of colours and flavoured malt extracts.

Malt extracts can also be used by homebrewers who do not want to use a grain-mash system. We can also use them as a malt base for propagating yeast.

Roasted malt beer extract is another type of malt extract that we can produce. Its production includes a standard brewhouse and fermentation process, whereby the wort is boiled and lightly hopped and then fermented. The malt base has a low fermentability and so the fermentation is completed in 24 hours. The beer is then primary filtered and then active carbon filtered to remove the burnt flavour notes. The beer is then concentrated using a vacuum evaporator.

The advantage of such a product is that it can be used as a pure colouring ingredient, with no need to add additional extract later in the process if the yeast has already been removed.