October 2024

We are currently running a 6-week student research internship in our research brewery, during which we are trying out some new beer recipes. Apart from a few exceptions, we only brew using the isothermal high-temperature mashing process with variable temperature, for which a new peer-reviewed publication is available as an open access article.
 

On October 30, we therefore brewed two beers with our 50 L system, which has a very powerful agitator and reduces the mashing-in process to just 30 seconds: a pale bock with around 16 °P and a pale ale with 11.5 °P. The malt bill of the bock beer consisted mainly of pale ale malt, rounded off with carapils and melanoid malt. For the student internship, we mashed for 60 minutes, analyzing the in situ original gravity, with 95% of the saccharification already completed after 30 minutes.
We used a non-isomerized hop extract from Yakimachief for the bitterness of approx. 25 IBU units, and we adjusted a subtle fruit aroma with the product Dynaboost from Yakimachief in the "Mosaic" variant in the whirlpool. This US hop brings aromas of pineapple, mango and passion fruit, as well as citrus flavors, and should not dominate the taste of the beer too much, but give it a pleasant tropical fruit aroma, which should go well with a light bock beer. The brew is fermented under pressure in Tank Ulla with Lallemand Brewing "Diamond" at 12 °C. It is now our standard yeast for bottom-fermented beers because it ferments neutrally and sediments very well, which in turn makes the filtration of our bottom-fermented beers much easier. With an original gravity of around 16 °P, we should be able to achieve an alcohol content of less than 4 % vol.
 

The Pale Ale was also made from Pale Ale malt, rounded off with Carapils. Here too, mashing took 60 minutes and the wort was boiled with a bitter hop extract from Yakimachief, with 25 IBU as the target. In order to give the beer the typical Pale Ale character without risking overfermentation due to the enzymatic activity of hop pellets, we carried out a whirlpool hopping with Dynaboost in the "Mosaic" variant. To further emphasize the aroma, we added the Yakimachief product Hyperboost in the "Mosaic" and "Simcoe" variants to the fermentation tank, Tank Mathias, directly after adding the yeast.
The wort is fermented at 20 °C with the Lallemand Brewing "Verdant IPA", which itself produces apricot aromas and, with beta-glucosidase, has an enzyme that splits off glycosidically bound aroma components, transfers them to the green beer and thus further emphasizes the fruity aroma. A few years ago, Braumagazin published a good article on this subject, which sheds light on the topic from a scientific perspective. The search terms for this article are "Braumagazin" and "Biotransformation von Hopfeninhaltsstoffen durch die Hefe".
At 11.5 °P, our Pale Ale should not have more than 2.5 % alcohol by volume, which is very moderate compared to commercial Pale Ales, which sometimes have 7-8 % alcohol by volume. It should be mentioned that, strictly speaking, these beers are not beers. Although all ingredients comply with food law, and our malt from Weyermann is even of Bioland quality, according to the so-called provisional beer law of 1993, hop extracts may only be added during boiling if the beverage is to be called beer. One reason for this is that hop extracts were also produced with chemical solvents at the time, and boiling was intended to ensure that residues of these were completely removed during boiling.
As we only use hop extracts that have been produced by the manufacturer using supercritical carbon dioxide, i.e. only the valuable components are extracted from the hops, this requirement from the Provisional Beer Act no longer really plays a role. Cold-hopped pale ale beers are therefore not beers in the strict sense in Germany, but rather specialty beers. On the other hand, the so-called "Purity Law" of 1516 makes no statement as to when hops may be added and in what form. Of course, there was no extraction with supercritical carbon dioxide in 1516, but the princes also did not specify whether the hops should be added fresh or dried as cones or as a powder or in another processed form.

On October 23, 2024, we brewed the last gluten-free beer based on quinoa as part of the now expired project. However, due to a non-disclosure agreement, we cannot go into any details at this point. As part of the project, our colleagues at the Technical University of Munich succeeded in producing a quinoa malt with a convincing taste, the final development stage of which has been incorporated into this beer.
In the BrewTools 150 Pro, i.e. mashed using the malt pipe technique, we added 130 liters of water with a hardness of 1 °dH (mixed from reverse osmosis water and tap water) and mashed a malt mixture, which was then subjected to the two typical rests in the high-short process. After lautering, souring and boiling with a bittering hop extract from Yakimachief, "Hallertau Tradition" was added as an aroma hop in the whirlpool. We achieved around 115 liters of wort with an original gravity of 11.5 °P, which was divided between two cylindrical-conical fermentation vessels. In one, the brew is fermented top-fermented with LalBrew Nottingham, in another bottom-fermented with LalBrew Diamond.
Based on previous results, we now carry out fermentation at a pressure of around 1 bar. Pressurized fermentation offers certain advantages when it comes to breaking down undesirable aroma components that arise in the intermediate stages, the beer is also enriched with natural carbon dioxide and we can no longer miss the time to close the valve for pressure build-up after the main fermentation. The disadvantage is that fermentation takes a little longer than non-pressurized fermentation. Both beers should be ready for filtering and bottling around the end of November, and apart from a small reserve quantity, both beers will be handed over to the company partner in the project.
 

This last brew also marks the end of our activities on quinoa-based beers for an indefinite period. Our experience with unmalted quinoa, which is readily available commercially, has been very variable, and a truly authentic beer was only feasible as a pale ale. However, the effort involved is very high, so we will produce gluten-free beers, which we would also like to offer in small quantities for events in the future, in a different way.
As part of the project, several accompanying student research projects and bachelor's theses were carried out and completed, the aim of which was to break down gluten by adding an enzyme. In this way, we were able to produce beers with a gluten content of well below 10 mg/kg using barley malt. A foodstuff with a gluten content of less than 20 mg/kg can be labeled "gluten-free" according to an EU directive. Using the ELISA technique, which is available in our laboratory, we can monitor the gluten content during fermentation and maturation, and the degradation is dependent on a number of parameters. The sedimentation capacity of the yeast plays a role, as does the fermentation temperature, but the hops are also not entirely without influence.
It can take up to 6 weeks for gluten to be broken down to such an extent that people suffering from coeliac disease generally no longer have a problem with such a beer and we can safely achieve values below 10 mg/kg. And even then, there is still a risk that highly sensitive people will react to traces of gluten in such a beer. Quinoa does not contain any gluten a priori, so it is certainly the better choice for absolutely gluten-free beers.
However, we have gained extensive knowledge in the course of our studies and bachelor's theses about how to produce gluten-free beers with barley malt. Unfortunately, there are also disadvantages. As the gluten-degrading enzyme contains glucoamylases, these beers will tend to have an alcohol content in the region of 5 % vol. at standard original gravity. We have not yet succeeded in producing beers with an alcohol content of 2 - 2.5 % vol. at normal original gravity. Although there are approaches to this, they need to be investigated in detail. In addition, we are not allowed to call these beers "beer" according to the so-called provisional beer law of 1993, which is the so-called purity law in the true sense of the word. The German Brewers' Association uses the term "beer specialty" for beers that, strictly speaking, are not brewed in accordance with the "Purity Law", while craft beers from commercial microbreweries are sometimes referred to as "brewery products". It should be mentioned that outside of Germany, such beers are also referred to as beer.

We will therefore end this article with the following quiz question: "It looks like a beer, smells like a beer, tastes like a beer, but is not a beer. What is it?"