Colour analysing of IPA brewing phases, including daily measuring of the fermentation process

Abstract

Over the last decade, the brewing revolution has shown a new face to brewing. Besides the large-scale production, small-scale, artisanal hand crafted, and home breweries have also become important and relevant. This change has forced large-scale companies to change their usual methods and brew other types of recipes as well.One of the most popular ALE-type beers is the Indian Pale Ale (IPA), which gives beer a fruity-citrus flavour due to its hop content. It is especially popular with novice brewers as it has no enormous machine requirements compared to LAGER-type beers.In the study, we made our already known and popular recipe, a New England IPA, in a 30-litre brewing pot. This type requires only one type of malt; however, we added barley flakes, oat flakes, and wheat flakes to enhance the flavour. Hops are very dominant in the taste of this type of beer, five of which were used during brewing and later at “dry hopping” during fermentation.Sampling was performed every minute during mashing, brewing, hopping, cooling, and yeasting with a calibrated NIX-type measuring device with repetition to avoid measurement errors. During the fermentation stage, the colour change was observed by daily sampling. The study aims to separate the stages of brewing by colour and identify the stages of the already known biological and chemical activities by colour. This study is the first part of a more extended series of experiments where we will perform similar experiments on several types of beer (LAGER, STOUT, APA, WHEAT, RED, etc.). We would also like to know about the possible effect of carbonisation on colour, the possible effect of storage in a bottle on colour, and possible deviations from a similar decoction.