What is beer exactly? The staple ingredients from which most beers are produced are Malted Barley, Water, Hops, and Yeast. The German purity law decreed that beer must be made from these materials ALONE, and many of the world greatest beers are still made according to this method.
The stages of beer production can be broken down into stages:
- Malting – The process begins with the receival into the malt house of specially grown two-row malting barley, which is steeped in water to germinate the grain. The germination releases hormones and enzymes that break down the cell walls surrounding the starch granules. This modification is halted by drying and kilning the malt. Different malts are made by varying the amount of heat, moisture and the duration of kilning.
- Mashing – Malted barley is then milled and mixed with water at the “Goldilocks temperature” (not too cold not too hot). The enzymes that remain from the malting really get to work on the starch granules converting them into simple sugars chiefly Maltose – Malt for short. It is this malt that will be converted to alcohol during fermentation.
- Kettling – The malt liquor produced in the mashing stage then needs to be vigorously boiled for at least an hour and up to two hours with the addition of hops at various stages. Kettling releases volatile substances that would spoil the beer and converts compounds (alpha acid) in the hops to bitter the beer. At this stage, it is called Wort (pronounce like Hurt) and is cooled to yeast pitching temperature and transferred into fermenters.
- Fermenting – This is where the majority of homebrewers begin, by adding back the water that was removed to make the malt extract or by using a fresh wort. The key to this stage is awareness of the temperature of the ferment for the type of beer you want to brew i.e. whether it is a lager (8-12°C) or ale (18-22°C). The next thing is knowing when to bottle. Often a brewer will ask how many days it will take to brew. I really wish it was as easy as that, but the truth is, it’s easy to understand once you realise that the yeast are in charge at this point. Fermentation is complete when all of the available fermentable’s have been consumed – in other words, the yeast have finished their tucker! This depends on many factors such as temperature, yeast strain, mineralization of the water, starting gravity and malt type to name a few. So to ascertain the correct bottling time we need to test with our Hydrometer or Refractometer, till a steady reading is obtained (three days in a row is a good guide). If you were to bottle early while there are still unfermented sugars, the extra could cause over gassed beers or in extreme cases blown bottles!