February 2023

On 22.02.2023, we brewed 100 liters of a hoppy aromatic Pale Ale beer using pressureless fermentation. The malt mixture consisted of around 80 % Pilsner malt and around 20 % Carahell. Mashing took place for 30 minutes at 74 °C in the Brewtools 150 Pro, and the subsequent lautering was completed after around 45 minutes. We obtained around 110 liters of iodine-normal wort, which was then boiled for 60 minutes with a bitter hop extract. As with the brewing process on 18.02.2023, it became apparent that much less trub settled on the vessel walls or on the vapour hood in the brewing system, which made subsequent cleaning much easier for us.
For the whirlpool hopping, "East Kent Goldings" (Pellets 90) was added at 82 °C as well as Simcoe as CryoHop. The former is described as spicy and earthy, with honey aromas, while the Simcoe is a typical IPA hop with aromas of pine, grapefruit and passion fruit. For the dry hopping, we heat-treated Hallertau Mandarina Bavaria and Huell Melon (both pellets type 90) in 80 °C hot wort for 5 minutes, as described in a recent publication, and immediately added them to the cooled wort in the fermentation vessel. In this way, the starch-splitting amylases, which hops generally contain, are denatured, thus preventing the so-called hop creep effect. The cold hopping was rounded off with the aroma hop extract "Spectrum" from Barth Haas, Citra variant, which does not have a hop creep effect per se. Standard cold-hopped beers generally have alcohol contents of 6 vol-% and above at original wort levels of around 12 °P, a result of the amylolytic breakdown of non-fermentable higher sugars to fermentable sugars such as maltotriose, maltose and glucose.
For the fermentation, we used the maltotriose-negative Empire Ale from Mangrove Jack's, a yeast that itself contributes "sweet" aromas and produces full-bodied beers due to the non-fermented maltotriose. Unfortunately, this yeast only has a low beta-glucosidase and beta-lyase activity, i.e. it only breaks down glycosidically bound aroma components from the hop ingredients to a small extent and therefore does little to emphasize the aroma. We therefore added commercially available beta-glucosidase, which, as shown in earlier experiments, emphasizes the hop aroma. As this yeast tends to sediment poorly, it will certainly take 6 - 8 weeks before a clear beer results. With an original gravity of 11.4 °P, we expect a maximum of 3.5% alcohol by volume.
 

The addition of beta-glucosidase is compliant with food law, but actually violates the so-called purity law. On the other hand, there are commercial dry yeasts that are enriched with beta-glucosidase, and strictly speaking these would not violate the purity law. We see this conflict of objectives primarily as being of a research nature: if the combination of a maltotriose-negative yeast with an enzyme and thermally treated hops in isothermally mashed wort enables the production of low-alcohol, aroma-rich pale ale beers in a reproducible manner, then there is also a way to do this within the framework of the Purity Law.

All of our cylindrical-conical fermenters (CCVs) are currently filled with maturing beers, so on 18.02.2023 we unpacked our non-thermostatted fermentation vessel with a volume of 200 L for the first time in a long time. We brewed in parallel with our Braumeister 50 and with the Brewtools 150 Pro.
This time we brewed a top-fermented pale ale with 75% Pilsner malt and 22% Carahell, rounded off with 3% Carared. Isothermal high-temperature mashing at 74 - 76 °C was used, and after 30 minutes we started lautering, which this time only took a little longer than 30 minutes and produced a total of 200 liters of wort with an original gravity of around 11 °P.
For the first time, we used a commercial hop extract for hop boiling, which is produced from hops using supercritical carbon dioxide. This type of hop extract contains only non-isomerized alpha acids and must therefore be boiled with the beer. It is easy to dose, the bitterness can be adjusted very precisely and it dissolves quickly in the boiling wort. Many large breweries use this type of hop extract to adjust the bitterness. We noticed positively that the brewing equipment was much easier to clean later compared with hop pellets for bittering. We will continue to experiment with this hop extract to adjust the bitterness in future brews.
However, aroma hopping was carried out using classic pellets 90: 100 g Rottenburger was added 10 minutes before the end of the boil, and we added 100 g Spalt Spalter to the whirlpool. The aroma of Rottenburger hops, which almost died out in the 1970s, is described as menthol, cedar wood, pine needles and green pepper, while Spalt Spalter, which belongs to the so-called highly refined aroma hops, is described with aromas such as floral, grassy and spicy.
The malt blend and hops could also be found in a Pilsner beer, but this time the wort is fermented at room temperature (18 - 20 °C) with the top-fermenting Lallemand BRY-97. We have previously used this yeast, which is also known as "American West Coast Yeast", for cold-hopped Pale Ale beers (India Pale Ale and Imperial Pale Ale). As it contains enzymes such as beta-glucosidase and beta-lyase, the fruit aromas in Pale Ale beers are emphasized. On the other hand, it is also described as slightly estery and almost neutral, making it suitable for more classic top-fermented pale ales. This yeast can ferment a brew within 4 days and is characterized by very good sedimentation, so a clear beer should result in about 4 weeks.

On 11.02.2023 we filled our small 50 liter ZKGs, and this time we experimented with a fairly new hop variant, namely Cryohop. We used our "Braumeister 50" and the Brewtools 150 Pro. This means that all of our ZKGs are now filled, and at least 400 liters of beer are now waiting to ferment and mature in peace. Further beers will be produced in pressureless fermentation in the coming weeks and subjected to forced carbonation after maturing.
 

We brewed a wheat beer with the Braumeister, 50% of which consisted of pale wheat malt. By law, a wheat beer must be brewed from at least 50% wheat malt if it is to be called a wheat beer. Around 40% of the malt mixture consisted of pale ale malt and around 10% of melanoidin malt, which adds subtle aromas of cookie and honey. At the same time, melanoid malt deepens the color. As wheat malt itself has no husks, we added rice husks for faster lautering.
We mashed for 50 minutes at 72 °C, and after lautering we obtained around 50 liters of wort with an original gravity of 12.3 °P. The wort was boiled with Enigma bittering hops and whirlpool hopped at 85 °C with Citra and Simcoe as Cryohop. Simcoe and Citra are typical IPA hops with tropical fruit aromas. Both hops are suitable for whirlpool hopping due to their high proportion of low volatile aroma components; however, they are also very popular for cold hopping ("hop plugging"). Cryohop differs from classic hop pellets in the way it is produced. Instead of drying hops on a kiln and processing them into traditional pellets, Cryohop is separated into the valuable lupulin components and the less important other plant components at very low temperatures and in the absence of oxygen. This prevents the more volatile aroma components from being released during processing and prevents oxidation of the hop ingredients, resulting in a more intense hop aroma. As the yeast used, WYeast 3068 (identical to Weihenstephan W68 or TUM 68), is very rich in aroma and emphasizes the banana aroma with high levels of glucose in the wort, the result should be a fruity, aromatic wheat beer. We are very excited about the result.

In the Brewtools 150 Pro, we used Pale Ale malt (66%), Carahell (25%) and Melanoidin malt (9%) in an isothermal mashing process at a constant 74 °C to produce 150 liters of wort at 13.5 °P. We finished mashing after 30 minutes with lautering, and the saccharification of the starch that had not yet converted took place during lautering, whereby the temperature of the brewing kettle was kept at 74 - 75 °C.
With a few exceptions, we always brew using the isothermal mashing process at temperatures between 72 and 76 °C and are always amazed at how quickly saccharification takes place. We deliberately want to denature the beta-amylase as quickly as possible so that only the alpha-amylase can break down the starch. This gives us a lower content of fermentable sugars and a higher content of non-fermentable sugars, with the latter increasing the so-called fullness of the beer. Mashing and lautering were completed after 75 minutes.
The wort was boiled with the bittering hop Enigma, and for the whirlpool hopping at 85 °C we used Simcoe and Citra as Cryohop, as with the wheat beer. What we liked about Cryohop is that these hops break down into a very fine powder in the wort, which passes through the plate heat exchanger without settling in it. This makes it much easier to clean, which is incidentally one of the reasons why hop extracts are often used in larger breweries, at least for adjusting the bitterness.
We ferment this brew, which is divided into 3 CCGs, with 3 different yeasts, namely the WYeast 1318 (London Ale III), the Imperial Yeast A38 (Juice Ale) and the LalBrew Diamond Lager, a typical bottom-fermenting and rather neutral fermenting Pilsner yeast. Both ale yeasts are capable of biotransformation, i.e. they break down glycosidically bound aroma compounds, while the bottom-fermenting yeast has little, if any, such activity. We already know from the trials in December 2022 that the two ales have a very similar taste. We are curious to see how Cryohop affects the aroma and how these two top-fermented beers differ in taste from the bottom-fermented one.

After a short brewing break, during which we emptied all the tanks and prepared them for new brews, we resumed brewing operations on February 4, 2023 and brewed 200 liters of an Amber Lager. The brew consisted of 30% Pale Ale malt and 40% Munich malt, rounded off with Melanoidin malt, Carahell and Caracrystal. This malt mixture produces a dark amber color and gives the finished beer numerous malty and caramel-like aromas.
This malt mixture was mashed isothermally at 72 - 74 °C, as is usual for us, in parallel in the Brewtools 150 Pro and in our Braumeister 50. We also carried out mash hopping, i.e. the malt was mashed together with Saaz green hops. Czech Saaz is a highly refined aroma hop whose aroma is described with attributes such as "earthy", "herbal" and "flowery", while the bittering content is rather low.
During mashing, hop oils are transferred to the wort, which do not necessarily evaporate completely during the subsequent wort boiling. The bitter hopping was done with the Australian high-alpha hop "Enigma", the whirlpool hopping with Hallertauer Blanc (Wethop), which gives the finished beer subtle fruity aromas. The aroma profile of the Blanc is described as "floral", "passion fruit", "gooseberry", "grapefruit" and "pineapple", with a "white wine bouquet" also being described.
The brew is fermented at 12 °C with Lallemand Diamond Lager, a rather neutral bottom-fermenting yeast that sediments very well and produces clear beers after a certain maturation period without filtering. Due to the complex malt and hop blend, this beer will need a little time to mature, but we expect it to be ready to drink from around mid-April. With an original gravity of 11.5 °P, we expect a moderate alcohol content of approx. 3.5% by volume.