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On 16.03.2023, we brewed another NEIPA before a break of several weeks. NEIPA stands for "New England IPA", and in these beers the typical IPA bitterness takes a back seat while the fruit aromas dominate.
Last year, we were able to produce very harmonious beers with the Ebbegarden Kveik, which met with very broad approval, also because our pale ale beers usually have an alcohol content of only 3 - 4 % vol. Unfortunately, this yeast was not available to order for a long time, and we were not entirely satisfied with the replacement yeasts such as Imperial Yeast Juice (A38) or WYeast 1318. In the end, we ordered the Ebbegarden Kveik directly from the manufacturer in Canada and were now able to brew with it again for the first time in more than 6 months.
We used a simple mash consisting of around 25 % Carahell and around 75 % Pale Ale malt and mashed it in the Brewtools 150 Pro, which will give the beer an almost orange color later on. Mashing was carried out isothermally at 72 °C for 30 minutes, and lautering at 72 °C was unproblematic this time and finished after 60 minutes.
We used a non-isomerized bitter hop extract for the bitter hopping with the target of barely perceptible 15 IBU units; no aroma hops were added in the hot phase. The approximately 100 liters of wort are now fermented with the Ebbegarden Kveik at an initial temperature of 25 °C. For the dry hopping, we have added the hop extract Spectrum from Barth Haas in the CITRA variant. This makes this NEIPA the first from our brewery to be brewed with hop extracts alone, i.e. without the addition of hop pellets or cones.
Ultimately, we were convinced by the simpler cleaning of the brewing equipment from the bitter hop extract, and the Spectrum product from Barth Haas has the unbeatable advantage that it is enzymatically inactive and therefore the dreaded hop creep effect, which leads to overfermentation when using fresh hops or hop pellets, does not occur during cold hopping. With an original gravity of 11.4 °P, we expect an alcohol content of approx. 3.5 % vol. As NEIPA beers are frequently requested, we will now brew them regularly.
On 11.03.2023, we largely repeated the brew from 18.02.2023, i.e. we brewed around 200 liters of a top-fermented pale ale with our Braumeister 50 and with the Brewtools 150 Pro. We changed the malt blend slightly, and this time the malt bill consisted of 40% Pale Ale malt, 35% Pilsner malt and 25% Carahell, which enabled us to achieve a slightly deeper color in comparison.
Mashing took place for 60 minutes at 74 °C, followed by mashing at 74 °C.
The lautering in the Brewtools system was unfortunately very slow this time, and the sieve bottom of the Brewtools system kept clogging up, so that the lautering in this system unfortunately took a long 2 1/2 hours, while the lautering in the Braumeister was completed after 45 minutes. One reason for this drastic difference in lautering time may lie in the design of the systems: In the Braumeister, the wort is actively pumped through the malt from below by 2 pumps, whereas in the Brewtools system it has to flow passively through the malt from above.
In addition, regular pumping breaks are inserted in the Braumeister, during which the malt loosens up a little. This inevitably results in compaction in the Brewtools system, which we found difficult to loosen directly at the sieve bottom. We will therefore add rice husks again for the next brew.
However, the "reward" for these efforts was that we achieved an original gravity of 12.5 °P this time, whereas in February we "only" achieved 11.4 °P with the same amount of malt. Our latest brewing system, Dani's BrewTower BT180, will soon be up and running, and we are looking forward to seeing how this system, which has a classic agitator, performs during isothermal high-temperature mashing. For the brew of March 11, 2023, we again used a bittering hop extract, which we use exclusively to adjust the bitterness. The brewing equipment is then much easier to clean than with hop pellets for adjusting the bitterness.
The latter leave a lot of residue on the heating coils, which can only be removed chemically and mechanically. For the aroma, Hallertauer Tradition was boiled for 10 minutes, the whirlpool hopping was done with Spalt Spalter. The brew is fermented with BRY-97 harvest yeast in pressureless fermentation under a fermentation bell. A first taste impression of the beer from 18.02.2023 is almost in the direction of "pilsner", so we expect this beer to be very drinkable with an expected alcohol content of 3.5% vol.
As our cylindrically-conical fermentation vessels are currently all full and various beers are maturing in them, we are currently brewing with pressureless fermentation again. This means that the finished wort is filled into fermentation vessels and fermented in these under a fermentation bell without pressure. In top-fermented brewing, the beers are then matured 4 - 6 weeks later after forced carbonation in pressurized barrels. This allows us to replenish our slowly dwindling supplies, because what could be worse than a brewery with no beer?
On March 8, 2023, we brewed a very simple dark wheat beer with a malt bill consisting of Munich malt, melanoidin malt, wheat malt and spelt malt. To further exploit the isothermal high-temperature mashing process, this time we mashed at 78 °C in the 50 L Brew Monk system. After mashing in, we achieved a temperature of 74 °C, which we kept constant for over an hour. Saccharification was completed after 30 minutes and the wort was iodine-normal, and the original gravity changed only slightly over the next 30 minutes.
Lautering was completed after 45 minutes, and after boiling with a non-isomerized bitter hop extract, which therefore has to be boiled as well, we obtained 45 L of wort with an original gravity of 11.1 °P. Fermentation is carried out with WYeast 3068, a wheat beer yeast that promotes the banana aroma, while Spectrum from Barth Haas in the Citra variant is used for dry hopping. This yeast usually ferments very quickly so that the green beer can be transferred to a pressure keg and carbonated after about a week. The aroma hops should add subtle citrus aromas and the beer should be ready to drink at the beginning of April.
In a recent publication, we showed how the hop creep effect, which leads to the overfermentation of IPA beers, can be avoided, resulting in fruity, aromatic beers with alcohol levels between 3 and 4 % vol. This time, we worked with a hop manufacturer to investigate whether a new hop product exhibits the hop creep effect or not. For obvious reasons, we cannot go into details, but we can provide some information.
In the Braumeister 50, we mashed pale ale malt isothermally at 74 °C for 60 minutes. The wort was boiled with a non-isomerized bitter hop extract, and we obtained 55 liters of wort with 11.1 °P. 50 liters of this was divided into 5 fermentation vessels and the cooled wort was sparged with a packet of LalBrew "Verdant IPA". This yeast is very interesting as it is capable of biotransforming hop compounds and also produces peach and apricot aromas during fermentation, making it a very interesting yeast for IPA beers. The new hop product was added to each of these fermentation vessels at the start of fermentation, in different variations. We let 500 ml of wort ferment without these hops as a reference, and later we will compare the chromatograms of the unfermented wort, the fermented wort and the beers with dry hopping to see whether the product shows hop creep. Whatever the outcome, it should result in interesting pale ale beers, which will of course be drunk later.
On 04.03.2023 we brewed scientifically again. We mainly deal with the isothermal high-temperature mashing process at temperatures between 72 and 76 °C and, with a few exceptions, only brew using this process. In earlier published work, we were able to show that Pilsner malt that was subjected to a classic 3-step infusion mashing process and that which was subjected to the isothermal high-temperature mashing process actually produced the same original gravity, with the difference that the finished beers, which are difficult to differentiate in terms of taste, differed by more than 1% alcohol by volume. The isothermally mashed beers have noticeably lower alcohol contents, and most of our beers with original gravities between 11 and 12 °P have alcohol contents of between 3 and 4% by volume, although 2% alcohol by volume is also possible with maltotriose-negative yeasts. However, we also brew with higher alcohol contents of around 5% by volume using variations of the isothermal process.
Today, large breweries mainly brew using the so-called "high-short mashing process", in which malt is mashed at approx. 65 - 66 °C, followed by a 20-minute rest at 62 - 63 °C. The beta-amylase is active in this temperature range. The temperature is then heated to 72 °C within 10 - 20 minutes, followed by a rest period of approx. 20 minutes at 72 °C, during which the alpha-amylase is active, before heating to the mashing temperature of 78 °C, at which the enzymes are largely inactivated. Mashing takes between 60 and 120 minutes, depending on the system. This time we compared the isothermal mashing of Pale Ale malt at 72 °C with the high-short mashing process and a high-short ultra mashing process, whereby the high-short ultra mashing process is further shortened.
Brewing was carried out in the BrewMonk 50 using the malt pipe technique. We do not want to go into details at this point, as the data is to be included in a publication, but the original gravities of the 3 brews were only around 0.5 °P apart in the full beer range. The lautering at 72 °C and its respective duration were also comparable, with slight nuances. The wort was boiled with a bittering hop extract in each case; we did not use aroma hops for the subsequent sensory evaluation.
All 3 wort brews are fermented with the new NovaLagerTM yeast from Lallemand Brewing. This yeast is a so-called lager yeast, which is a cross between a top-fermenting strain (Saccharomyces cerevisiae) and an original strain (Saccharomyces eubayanus), from which today's bottom-fermenting yeasts (Saccharomyces pastorianus) presumably originated. The NovaLagerTM has a very wide temperature range, it can be used at typical bottom-fermenting temperatures of approx. 10 - 15 °C, as well as at typical top-fermenting temperatures of 20 - 25 °C, which leads to a higher concentration of aromatic esters.
We ferment these 3 wort types at 15 °C, which is also how we want to find out whether the NovaLagerTM can be used to brew flavorful pilsner beers. Lallemand states that this yeast produces only small amounts of vicinal diketones and diacetyl, and also no hydrogen sulphide, the breakdown of which requires a certain maturation time in classic bottom-fermented beers. On the other hand, a small amount of hydrogen sulphide is desirable for the typical pilsner taste. These 3 beers are later subjected to a professional sensory evaluation and the typical aroma components are determined and compared.