April 2023

After a long break from brewing, we brewed a Pilsner beer again on 26.04.2023, partly accompanied by a film team from Clausthal University of Technology.
We used our BrewTools 150 Pro and our 50-liter Braumeister from Speidel at the same time. The batch consisted of 35 % Pilsner malt, 40 % Pale Ale malt and 25 % Carahell, which will give the beer a golden yellow color. Mashing was carried out using an isothermal high-temperature mashing process at 72 °C for 30 minutes, followed by lautering at 72 °C for approx. 60 minutes. The malt was washed out further during lautering with water at 78 °C, while the temperature of the wort was kept constant at 72 °C to ensure that any starch washed out of the wort was saccharified.
The two brewing systems together produced 200 liters of wort at 11.5 °P, which is a typical value for a pilsner beer. The wort was boiled together with sour beer (to lower the pH value) for 60 minutes with a non-isomerized hop extract, the aroma hopping was carried out at 80 °C in the whirlpool with the classic aroma hop "Spalter Select" (Pellets 90), which is described as "herbal", "flowery" and "earthy". The bitterness of the finished beer will be around 35 IBU, typical of pilsner.
The wort is fermented at 12 °C in our "Tank Siegfried" with WhiteLabs WLP 800. According to the manufacturer, this is a Czech pilsner yeast that emphasizes the bitterness and malt character of a beer. It has a good flocculation capacity, so that after a certain maturation period we will obtain a clear beer without any filtration.
Czech Pilsner yeasts tend to form increased concentrations of diacetyl, especially during cold fermentation below 10 °C. In Czech Pilsner beers, for example in the well-known "Pilsener Urquell", an increased diacetyl content, which manifests itself in a slightly buttery to caramel-like taste, is expressly desired. In Germany, an excessively high diacetyl content (> 0.1 mg/l) is perceived as a deficiency in the sensory evaluation, whereas in Czech beers it is regarded as a quality criterion. Diacetyl, which is produced by yeasts in amino acid metabolism, can be broken down if the fully fermented young beer is heated to 14 - 16 °C for a few days.
Yeast cells in suspension break down the diacetyl at this temperature. We expect around 3.5 % alcohol by volume in the finished beer, which should be mature at around the end of June. Bottom-fermented beers need time to mature.