just got back from the class! i want to give a huge thanks to brooklyn homebrew and jason the microbiologist for his very informative class.
the beginning of the class talked about the physical aspects of yeast cells and how they metabolize sugar into c02 and alcohol. he also brought slides of different types of yeast and we got to see them under a microscope. got to see 1056 budding and some brett, which is really long and rod shaped, unlike the spherical 1056. that part was cool.
he taught us a cool thing about how to check for diacetyl. you need two class, a cold water bath and a hot water bath, a thermo and some aluminum foil. pour some wort (fermented but before bottling) into the glasses and put one into the hot water and one into cold, covering with foil. let sit for 20min. then take the hot sample and put it into the cold water, you want to make them the same temp. take off the foil and smell. the cold is your control, if the hot sample smells buttery, you need more time on the yeast.
he really stressed temp control and aeration. temp differences of 3 degrees in the first few days of fermentation can really change the flavor, so if you don't have temp control, get it!
another interesting thing was mixing yeasts. start off fermentation with one yeast strain and when you get about halfway through, pitch your second strain and you will get something from both, whether it's super attenuation or a flavor. if it's a low gravity brew, just pitch them at the same time. i'm thinking about mixing saison and english yeast for some kind of mutant high attenuating pepper fruit beast.
last thing was the proper way to step up a starter. don't just cold crash and pitch fresh wort onto the starter cake. you get yeast growth from small beginning numbers of yeast so pull 100ml of starter wort and pitch that into the fresh starter wort, cold crashing the first starter and mixing them when done, you'll get vastly more yeast.
i picked out the overpitch brew but mixed up the under and the control. overpitch was very thin, under was bubblegummy and the control was more fruity. i was just glad to get one haha.