This page is fully or partially automatically translated.
Make an appointment with
So that you can make an appointment, the calendar will open in a new tab on the personal profile of your contact person.
Create an onsite appointment with
So that you can make an onsite appointment, the appointment request will open in a new tab.
Cultured and foreign yeasts
We want to start our look at yeast and other microorganisms relevant in beer with a focus on quality assurance.
Because even if you never want to deal with the topic, contamination with wild yeasts unfortunately cannot always be avoided in operational practice. In the case of microbiological abnormalities, it is important to make an initial classification of the foreign and harmful organisms involved. The article "Harmful yeasts, wild yeasts, foreign yeasts“ can serve as a brief technological-taxonomic reference work.
Harmful organisms have a hard time surviving in beer. Nevertheless, there are some beer spoilage organisms that thrive in beer despite alcohol, low pH and CO2. If it is indeed a matter of eliminating contamination, suitable countermeasures must be taken. And this must be done as quickly as expertly. An overview of the most common beer spoilage organisms, common detection methods and concrete recommendations for action can be found in the article "What to do in case of microbiological problems?“ for those who urgently need to take action.
In the microscopic image, Saccharomyces cerevisiae var. Diastaticus cannot be distinguished from cultured yeastOver-fermenting
Until the turn of the millennium, problems with Saccharomyces diastaticus were hardly ever heard of in Germany. For some beer styles, S. diastaticus is used as a culture yeast (especially in Belgian beers), but as an over-fermenting beer pest, "Diastaticus" can also have nasty consequences, up to and including bombage of bottles. Detection is complex, because it is possible to inoculate end-fermented beer with Diastaticus, and if gas develops, the case is clear. But to do this, the laboratory first needs a pure culture. And this is not easy to isolate, because Diastaticus yeasts cannot be visually distinguished from "normal" brewer's yeast. Only molecular biological tests currently provide analytical certainty as to whether there is contamination with S. diastaticus (or the corresponding genes in the test substrate).
Although beer is not an ideal medium for lactic acid bacteria due to various hurdles, some species can defy the adverse conditions in beerLactic acid bacteria
Not only with S. diastaticus, but also with lactic acid bacteria, opinions differ. In beer styles such as Berliner Weisse or spontaneously fermented sour beers, they are considered "beneficial organisms" by some brewers. But in most beer styles, lactic acid bacteria are undesirable as beer spoilers. Which lactic acid bacteria occur as beer spoilage agents? How was this group of bacteria able to adapt to the actually adverse conditions in beer? The article "Lactic acid bacteria in breweries – friend and foe“ provides answers.
Speaking of lactic acid bacteria: In the course of the craft beer craze, sour beers have also found favour again with many a beer lover. The processes used to produce sour beers are as diverse as the microorganisms that give them their characteristic aroma. Be it with modern kettle souring or traditional mixed fermentation with years of maturation. Find out more about the renaissance of sour beers.
In this bottle, an old cultured yeast survived for over 50 years before it was "brought back to life" by the yeast specialists at BLQNew and old (culture) yeasts
More exciting for a master brewer than worrying about eliminating contamination is developing new recipes. That's where you can let your creativity run free. And perhaps recipe development has never been as exciting as it is today. There is not only the challenge of future-proofing one's core range by switching to climate-resistant hop and malt varieties. No, there are so many new things here, so many more strains to discover. The spectrum of potential possibilities can hardly be estimated. And in the end, of course, it is always exciting when the search for yeast treasures is rewarded with a direct hit.
Sometimes rummaging around in storerooms and fridges that have been neglected for a long time brings surprising things to light. This is what happened at the TU Munich, for example. A forgotten box with freeze-dried, numbered yeast samples could be reconciled with historical laboratory documentation: The yeast strain TUM 35, thought lost, was rediscovered. The reactivation was successful, and the yeast strain now deposited at the Weihenstephan Research Centre under the brand name "Franconia TUM 35" convinced in fermentation tests with its excellent sensory properties.
Will breweries in future not only declare the hop and malt varieties used on the label, but also the microorganisms involved? To get you used to the names: Saccharomycodes ludwigii, Cyberlindnera misumaiensis, Cyberlindnera saturnus and Kluyveromyces marxianus are some of the latest promising "yeast stars".
Interdisciplinary fermentation
Attractive microorganisms are not only found in old cellars and on old trees. Sometimes it is enough to look over the edge of one's plate to one's colleagues in enology: Metschnikowia pulcherrima is used in wine production. Fermentation experiments indicate that the low-fermentation yeast can improve the aroma profile of beer, either as a pure culture or in mixed culture with S. cerevisiae.
Open fermenting vats not only bring technological advantages, they are also suitable as a showcase for brewery toursYeast management
The yeast wants to be treated well, there is no difference to "normal" employees. Many problems in and after the cold area of a brewery can be eliminated if one follows the principles of modern yeast management.
This is because a cleanly managed yeast ferments without any problems and ensures the microbiological safety of the wort and the finished beer, for example, through a rapid pH drop. But what to do if it becomes necessary to stop brewing for some time, as was necessary during Corona in some operations? The right pre-treatment, adapted storage conditions and a good reactivation technique ensure a smooth start-up process in the brewery , even after a longer standstill lasting months.
Traditional vat fermentation in a modern guise
A real "gamechanger", as they say, for breweries was the widespread introduction (in the 1950s) of the cylindroconical fermentation and storage tank. With closed product management, brewers could ensure higher microbiological safety. The tall, slender tanks also enabled efficient and reliably reproducible fermentation. For some years now, however, breweries and plant manufacturers have been returning to a traditional plant design, which until then had eked out a niche existence mainly in top-fermented wheat beer breweries: open vat fermentation. Not only can demonstrably improved technological properties be achieved with this process, the brewery can also use it to position itself as tradition-conscious in an effective advertising manner. And open-vat fermentation brings the brewer a little closer to his product. What opportunities does traditional vat fermentation offer modern breweries?
What will the future bring?
What does the future hold for the fermentation industry? Will new methods and entirely new processes prevail, such as continuous fermentation with crossflow filtration? Will breweries become part of a new form of food production in which natural raw materials are "cultivated" in bioreactors? In any case, the possibilities are hard to foresee. Fermentation technologists, and that's what brewers are, will continue to be able to let off steam creatively, and in a larger playground than ever before.
