By tov617, Oct 17 2017 08:18AM
For over 10,000 years humanity has been trying to harness the biological and chemical alchemy that makes beer using basic ingredients usually: water, barley, hops and yeast. Scientific advancements have only relatively recently understood the complex chemical reactions that occur during the brewing process.
A simple grass known as barley grows grains that exist to reproduce and provide a food source for the new plants. The malting process tricks the barley into germinating creating fermentable sugars and amino acids in the process. Mixing this malted barley with warm water sets off another chemical reaction producing a sweet liquid known as wort. This is known as mashing, much like making a cup of tea. The wort is then transferred to a vessel in which it is boiled, thus initiating another chemical reaction. Hops added during the boil give bitterness to the beer. Hops contain alpha acids and the boiling process helps fix these acids in the solution. Hops also contain volatile compounds giving distinctive flavours and aromas, and boiling will evaporate these compounds, so the art is to add these hops at the latter stages of the boil or at ‘flame off’ thus retaining flavour and aromas. The wort is now a bitter/sweet concoction and needs to be rapidly cooled before the introduction of the essential ingredient: yeast. The ‘run off’ process through a heat exchange reduces the temperature providing the right conditions for the yeast to flourish and instigate the fermentation process. Those sugars released during the malting process now provide essential food for the yeast to feed on, and feed they do, gobbling the fermentable sugars like glucose and maltose, producing carbon dioxide and alcohol as waste products. And three weeks later you’re drinking a cool, refreshing beer full of flavour. #Inktober2017