Deutsch
English
On 30.10.2021 we brewed a dark bock beer and a smoked beer. Munich malt, Melanoidin malt, Carahell and Caramünch were used for the bock beer, supplemented by a small amount of Carafa colored malt to deepen the color. Mashed isothermally at 72 °C, we achieved an original gravity of just over 16 °P after boiling with Enigma bittering hops and Rottenburg aroma hops. Bock beers have original gravities between 16.0 and 17.9 °P, from 18.0 °P they are referred to as doppelbock. The alcohol content of dark bock beers is usually between 6 and approx. 7.5% by volume, with doppelbocks sometimes reaching up to 10% by volume. As we have mashed isothermally at 72 °C, we expect a moderate alcohol content of approx. 4% by volume based on dark bock beers brewed in the same way in the past. The brew is fermented with bottom-fermented TUM W 34/70, which should harmoniously round off the malt aromas. The dark bock, of which we produced around 50 liters, should be ready to drink from mid-December - late, but still.
The second beer we brewed was a smoked beer. Smoked beers are particularly popular in Bamberg, where they are sometimes made with 100% smoked barley malt. A brewer friend of mine likes to compare such smoked beers with a "Black Forest ham". Some people love such smoked beers, others not so much, and some say: "It tastes good from the 4th beer onwards!". Well, tastes differ, and that's probably a good thing. We brew our smoked beer with only around 35% smoked beech malt, Munich malt makes up 65% of the grain bill, supplemented by a little colored malt to intensify the color. As is almost always the case with us, mashing was isothermal at 72 °C, and after hop boiling with Enigma and Rottenburg aroma hops in the whirlpool, we achieved an original gravity of almost 13 °P. The brew was fermented with Lutra Kveik, which ferments very quickly and also sediments very well. Lutra Kveik ferments almost neutrally at 20 °C with a so-called "lager characteristic" (similar to bottom-fermenting yeasts) and seemed to us to be a good alternative to a bottom-fermenting smoked beer yeast due to the delay. If nothing unexpected happens, the mild smoked beer will be ready by the end of November, so nothing will stand in the way of a pre-Christmas cheese fondue. We have produced a total of around 50 liters and expect the alcohol content to be a moderate 3 - 3.5% by volume.
"And before you know it, it's Christmas again" is a saying we say every year after the Christmas break. And so it happened again this year, and we should have had the Christmas beers such as our dark bock and our mild smoked beer (perfect with a Christmas cheese fondue) in the tanks by 23.10.2021. However, we have had to postpone these due to science and will therefore not be able to brew the bock beer and the smoked beer until 30.10.2021. Nevertheless, nobody has to miss out on bock beer. Master brewer Siegfried Oppermann has brewed a dark "winter beer" in the brewing academy, which will be served in the Biermünze from around November. At 19.3 °P and 8.1% alcohol by volume, it will certainly warm even the coldest feet in a figurative sense - but "be careful, only a few sips each, otherwise it will go to your head".
As you can read further down on this page, we are experimenting with low-alcohol IPA's (Imperial Pale Ale, India Pale Ale) and wrote the following:
"With the second 50 L we are trying to produce a "Kveik Pale Ale" in pressureless fermentation. The boiled and cooled wort was cold hopped from the start with Ariana and Blanc Wethop, for fermentation we took fresh Laerdal Kveik from Tank Siegfried and added it to the wort. This yeast ferments at around 35 °C without any undesirable fermentation by-products and should harmonize well with the "fruit salad" aromas resulting from the yeast, the Nelson Sauvin and the Ariana and Blanc cold hops and produce a nice "Kveik Pale Ale". If the wethop is enzymatically inactive, we expect a maximum of 3.5% alcohol by volume."
The analysis of this beer has now shown that with an original wort of 11.4 °P we achieved an alcohol content of only 3.0% by volume, with a bitterness of a good 55 IBU units, i.e. corresponding to the beer type (Pilsner beers are usually between 30 and 35 IBU). Commercial IPAs usually reach alcohol contents of between 6 and 8 vol%, and our "ImPerAtor", which was completely drunk, also reached 8 vol%, very tasty indeed, but also not entirely harmless. Selected test drinkers have now evaluated the aroma profile of the Kveik Pale Ale and have clearly placed it in the "IPA" category. At the rather high fermentation temperature of 35 °C, however, some aromas were certainly driven out, which is why we repeated these experiments on October 23. The 100 liters of wort were produced in exactly the same way as before, and the hot and whirlpool hopping was identical to before. We minimally reduced the amount of WetHop and changed the fermentation as follows: 50 L were fermented at 20 °C with the Laerdal Kveik (again directly from Tank Siegfried), 50 L at 20 °C with the Voss Kveik. The slightly lower fermentation temperature should emphasize the hop aromas and slightly reduce those of the yeasts. Both yeasts sediment very well, especially in the 2nd fermentation, the beers therefore do not require several weeks of storage and are already quite clear 2 weeks after brewing. Samples were taken from the finished wort for later analysis using high-performance liquid chromatography (HPLC) and immediately frozen at -20 °C. At the slightly lower fermentation temperature, fermentation should be completed after 5 days, and with the comparative analysis of the prepared wort and the finished beers, we can later assess via the respective sugar chromatogram whether the hops were definitely enzymatically inactive. Both beers will later be evaluated by colleagues from the Research Center for Brewing and Food Quality at the Technical University of Munich (BLQ).
After all, we were able to produce a black beer on October 23rd, which is also semi-experimental. In published work, we were able to show that dark Munich malt, which is weaker in enzymes than pale malts, can also be mashed isothermally at 72 °C without any problems. With an original gravity of around 11 °P, we achieve alcohol contents of around 2.5% by volume with 100% Munich malt. This time we used around 75% Munich malt in the recipe, 16% melanoid malt and 9% Caramünch, i.e. only 75% of the malt mixture is enzymatically active. We also added a little carafa to deepen the color. We brewed in the "Braumeister 50", which reached its limits this time in terms of pumping capacity with 11 kg of malt and 50 liters of main pour. The bitterness was set to a calculated 20 IBU, and we used the spicy "Rottenburger" aroma hops in the whirlpool. The brew was fermented with the TUM W34/70 in the second run-off. With a measured original gravity of just under 11 °P, the alcohol content of this beer should be between 2 and 2.5% by volume, and it should be ready in time for Christmas.
The production of non-alcoholic beers is challenging, especially in microbreweries, because normal yeast fermentation is always associated with the formation of carbon dioxide and alcohol. In addition to the various dealcoholization processes for normally brewed beers, brewing textbooks also contain other approaches such as yeast growth at very low temperatures, where the yeast only multiplies by breaking down sugars without forming alcohol, or stopped fermentation. In the latter case, the beer is brewed with a reduced original gravity of approx. 7 - 8 °P to prevent it from becoming too sweet. Normal fermentation is started and fermentation is stopped at the latest when 0.5% alcohol by volume is reached. A certain degree of fermentation is necessary because carbonated wort does not taste like beer. This is due to various aldehydes and ketones that are first metabolized by the yeasts, and it should not be forgotten that yeasts produce a whole phalanx of aromas that give the beer its character. Fermentation can be stopped by thermal treatment or by fine filtration, and some smaller breweries brew using these methods. Simple beers can also be produced with original gravities of around 2.5 °P; these contain so few fermentable sugars that an alcohol content of 0.5% by volume is easily achieved with ordinary brewer's yeasts. With maltotriose-negative yeasts, an original gravity of 3 °P with 0.5% alcohol by volume can also be achieved. Simple beers may taste a little watery, but they are great thirst quenchers, especially in summer, and with the numerous aroma hops available, it is still possible to brew highly drinkable beers.
Together with our colleagues at the Research Center for Brewing and Food Quality (BLQ) at the Technical University of Munich (Director: Prof. Dr. Fritz Jacob), we are working on full-bodied alcohol-free beers (max. 0.5% alcohol by volume) that are produced with so-called maltose-negative yeasts. These are being studied intensively at BLQ and our contribution is to use the isothermal mashing process at temperatures of 72 °C and above. We now brew with the "Ludwig yeast" (TUM SL17 - Saccharomycodes Ludwigii) as standard, and at an original gravity of 7.5 °P we reach the limit of 0.5% by volume without the beers lacking in flavor. With TUM 247(Cyberlindnera saturnus), we have already brewed the first wheat beer that achieved an alcohol content of just 0.5% by volume at an original gravity of 8.5 °P. This yeast produces a soft aroma of pears, berries and ice candy flavors are also described. In our experience, this beer is already well drinkable 4 weeks after brewing, but with a storage time of 3 - 6 months at 2 °C it becomes even rounder in taste. On October 9, we used another yeast from our colleagues in Munich, the maltose-negative TUM 242(Cyberlindnera amylophila). This yeast utilizes glucose, but not maltose, maltotriose and higher. This time we mashed Pale Ale malt and Carapils isothermally at 72 °C and set an original gravity of 12 °P. We hopped only with Hallertau Magnum bittering hops and set a bitterness of approx. 20 IBU. We diluted 7 liters of this 30-liter brew with 3 liters of boiled water to achieve an original gravity of 8.4 °P. The bitterness should be a maximum of 15 IBU, i.e. at the limit of perceptibility. These 10 liters of wort are now fermented with TUM 242, which produces typical wheat beer aromas, without pressure under a fermentation bell. We split the remaining 23 liters of wort between 2 fermentation vessels. We fermented part of the wort with the "Philly Sour". This is a special wild yeast from the Lachancea family that produces a not too high amount of lactic acid and aromas of stone fruit during alcoholic fermentation; apple and tropical fruits are also mentioned. Sour beers such as "Berliner Weisse" or the Belgian "Lambics" are actually typical summer beers, but why not drink them in the fall and winter? We ferment the second part wort with a classic "Irish ale" yeast, which is intended to support the malt character of the beer without introducing too many fruity esters.
We always test new recipes in small batches with malt mixtures that are not too complicated, because what brewer likes to throw away a large quantity of a beer that is not quite right?
After a 3 week break from brewing (how quickly time flies), the time had come again on October 2nd and we fired up the Braumeister 50 and the Brewtools 150. This time we brewed "advanced experimental" and used the Braumeister to produce a dark low-alcohol/alcohol-free beer with an original gravity of around 7 °P. The brew, made from Munich malt, melanoidin malt and sour malt and hopped only with Hallertau Magnum, is fermented with TUM SL17(Saccharomycodes Ludwigii), which only utilizes the sugars sucrose, glucose and fructose, which occur in small quantities. Due to the low pH drop during fermentation, the addition of sour malt or sour beer is absolutely necessary in order to precipitate out the scratchy, bitter hop components and make the beer easy to drink. In our previous trials with maltose-negative yeasts, 25% sour malt has proven to be optimal. We expect an alcohol content of 0.5% by volume, which would make the beer non-alcoholic according to the legal regulations.
As we have had a lot of good experience with the Norwegian Kveik (yeasts), we used the Brewtools 150 system to produce 100 liters of wort from Pale Ale malt and Carahell. After hop boiling with Hallertauer Magnum and Nelson Sauvin (the latter in the whirlpool), we achieved an original gravity of 11.3 °P. Nelson Sauvin is a fine but not quite inexpensive New Zealand aroma hop with aromas of Sauvignon Blanc, gooseberry and grapefruit. The brew has been split, 50 L of which will be fermented in the ZKG with the Lutra Kveik, and the finished beer, which has a "lager characteristic", should be easy to drink with subtle fruit flavors. We expect 3 - 3.3% alcohol by volume.
With the second 50 liters we try to produce a "Kveik Pale Ale" in pressureless fermentation. The boiled and cooled wort was cold hopped from the start with Ariana and Blanc Wethop, for fermentation we took fresh Laerdal Kveik from Tank Siegfried and added it to the wort. This yeast ferments at around 35 °C without any undesirable fermentation by-products and should harmonize well with the "fruit salad" aromas resulting from the yeast, the Nelson Sauvin and the Ariana and Blanc cold hops and produce a nice "Kveik Pale Ale". If the wethop is enzymatically inactive, we expect a maximum of 3.5% alcohol by volume.