Loading... Please wait...

Grain

Cereal grains are one of the basic ingredients of any beer. A few different varieties of grain are used for brewing but the most common grain used by far is barley.

Most or all of the grain used in any beer will have undergone a process called Malting.

beer-and-malted-grain.jpg

Malting Grain

The process of malting grain stimulates the production of diastatic enzymes. These enzymes are necessary during mashing for the conversion of starch within the grain to malt extract which consists of fermentable and non-fermentable sugars.

Malting also contributes to flavour and colour development within the finished grain.
While different grain varieties require different conditions during the malting to obtain optimum malt extract, the basic process itself is the same.

Malting is a three step process, starting with steeping the grain in water followed by germination of the grain and finally kilning the grain to stop the malting process.

Steeping (A)

 Steeping starts the germination process as grain moisture is increased from 10% to between 42% and 48%. The process involves repeated soaking of grain in water for 5 to 8 hours at a time. In between soaking sessions, water is drained and the grain allowed to rest while being exposed to air.

Germination (B)

 When the soaking sessions are complete, the grain is transferred from steeping tanks to germination boxes for root and shoot production. The endosperm, which is the energy source of the grain during early growth, also changes in structure in a process called modification.

Diastatic enzyme production in the grain is controlled by manipulating the humidity and temperature of the germination bed.

Germination aims to maximise grain modification and minimise root and shoot growth. Excessive growth results in less malt extract.

malting-process.gif

Kilning (C)

 Germination must be stopped when the barley shoot is about three quarters the length of the grain (about four days). At this point, the germinated grain is placed in a kiln where heat is applied. Kilning dries the grain and helps in the development of colour and flavour.

Different kilning temperatures and longer kilning periods will produce different flavours and colour profiles.

Lower kiln temperatures are used to ensure the survival of diastatic enzymes required for the mashing process. Less colour is generally produced at lower temperatures but the increased enzyme levels lead to a malted grain that will produce more fermentable sugars.

Higher kiln temperatures produce darker grains with reduced malt extract potential. These grains are used to modify the flavour of beers as well as provide darker colour profiles.

malted-grain.jpg

Unmalted Grain

Not all grains used in the brewing process are malted. Some unmalted grains may be used to modify the body, mouth-feel or colour and flavour of beer without adding any extra fermentable sugars. Some are used to improve the head retention of beer or even add a particular haze to certain styles of beer.

Grain Colour Scales

 The brewing industry measures the colour of grain using three different scales. The Lovibond Scale as developed by Joseph Lovibond in the 1860s, the Standard Reference Method (SRM) and the European Brewing Convention (EBC). All three scales identify grain colour on an ascending scale. The lighter the grain colour, the lower the value. The darker the colour the higher the colour. The EBC rating is the scale most commonly referred to in Australia.

colour-scale.jpg