Beer Research
Since I normally work with open kettle load&go recipes for beers, I come across interesting effects of multiple yeasts. Not much was known yet about the behaviour of multiple yeasts in a brew. So I picked some of my beer spots and started collecting data there. Soon the amount of data got out of hand *grins*. So here's the summary of my findings; for the data and discussion of them check the separate Case pages.
Case: VP Date Spot
This
case is interesting, because it produces a VP Date beer, while the first 2 yeasts that are present there are on their own not capable of making enough alcohol to produce a VP beer.
Summary/Conclusions
- In a multiple yeast beer, yeasts on any position of the microbe list can contribute to the result. Vitamin and sugar floor values and alcohol ceiling values of the yeasts determine if a yeast can become active.
- In this case, the first yeast on the list was allowed to reach its full potential of the brew. Several theories to explain this have been proposed.
- The second yeast entered the kettle shortly after the first. The net result was that activity of a second yeast in the beer added to the alcohol and flavours of the beer.
- The third yeast that contributes to the beer on this spot was found to enter very late, but still was able to make a substantial contribution to the beer.
- Data from this spot have been used by Amtep to formulate a model for the behaviour of multiple yeasts in a beer. This "Working Together Apart model", that was based on the Fermentation Tick theory explains the data very well. Yeast stats and yeast entry times are the main ingredients for this model.
- Two variations of the model have been proposed. The data from this spot were not conclusive to choose between the two variations.
Case: High Alcohol Spot
This
case is very interesting too, first because it is be possible to reach very high alcohol percentages here, but also because it shows that different yeasts can be activated in a beer depending on the conditions.
Summary/Conclusions
Case: Banana/Cinnamon spots
Based on previous cases, it might seem that the first yeast in the batch always gets to do its work until it hits a floor or alcohol ceiling. However, this is not always the case. An example of a different behaviour can be seen in the area where Banana/Cinnamon beers can be made. Here's the
case report.
Summary/Conclusions
Case: Ticks
During experiments done for other cases, I stumbled on a bunch of data that support the
Fermentation Tick theory. So I bundled them up
here.