[UPDATE 2011-05-20]
We measured the gravity and tasted all the different wild yeasts (except the Gueuze No. 3, that one barely started to ferment).
Wild Yeast 1: Gravity is 1014. The smell is sweet, like caramel. Tastes a little tart, but pleasant. Strong malt flavour. The beer tastes a little dry, which is strange for the 1014. Strong smell of caramel, interesting.
Wild Yeast2: Gravity is 1015. The smell is not sweet, but very fruity, strong “sprite”/peach smell. Very surprising and nice. Not a tart taste, very smooth. No caramel flavour as for the other yeast.
Wild Yeast3: Gravity is 1050. Strong smell of ham/bacon roast. Sulfury nose, and “barnyard” taste smell. Probably a Brett strain, which explains the slow fermenting.
Wild Yeast4: Gravity is 1038. Smell of damp basement, old mattress, but not so strong smelling as No. 3. Very bitter flavour, especially after taste, tastes a little like chewing on a pit from a berry, this kind of bitterness. This yeast seems to live mostly on the bottom of the 1 gallon bottle.
Wild Yeast5: Gravity is 1050. My lord, what have we isolated here. This yeast grows in long chains, and made the beer very viscous earlier. Well, now it smells like sweaty feet, extremely bitter and very tart. Very nasty.
Wild Yeast6: Gravity is 1040. Also the typical horseblanket/saddle smell, not pleasant as it is.
Wild Yeast7: Gravity is 1050. Very sweet still, but sour notes. Also smell of barn.
Gueuze Cantillon Isolate 1: Gravity is 1040. Very very clear ferment. Yeast definitely likes to live on the bottom here. Smell of apple, sourness, very much “puke-ish” gueuze nose and taste. Still young, but this one will be good. Brettanomyces lambicus?
Gueuze Cantillon Isolate 3: We did not measure this one, although its fermenting, 1 bubble per 16 seconds (airlock).
Gueuze Cantillon Isolate 4: Gravity is 1045. Very similar to the wild yeast we picked up, also smell-wise.
None of these yeasts formed a pellicle like the Bretts sometimes do. Reasons for this are unclear, maybe there was enough oxygen dissolved in the wort, or maybe we inoculated with a lot, who knows.
These guys need definitely months to mature (if they will). We definitely did take a walk on the wild side here.
So, again an update on the fermentation of the wild yeasts.
I did not measure the brix of the different vessels, since fermentation was until now very slow for most of them (except for Wild Yeast 1 and Wild Yeast 2). Wild Yeast 1 and 2 stopped fermenting prematurely around 1.040 (OG was 1.065) so they stopped very quick.
I added big amounts of cells for all the variants, except for the Gueuze cultures (just because I did not have the means to prepare pre-cultures of 11 different candidates).
The next day, No. 4 was definitely fermenting much more vigorous, and some bubbles were appearing at Wild Yeast 1. The rest did not show any activity. One interesting fact is that Wild Yeast 5 made the beer tremendously viscous, it is almost a gel. I have never seen that before, and it is certainly not going to produce a drinkable beer, but it is interesting from a microbiological perspective.
I am a little disappointed in how the yeasts have been performing until now, mainly I think we should have aerated and added more nutrient to help them a little, but, it is still early days (one week or so).
A short update on the behaviour of the 11 yeasts.
No. 1 started fermenting hard immediately, but it sunk in activity after 2 days, and now it really slowed down. The gravity sunk from 1.065 to 1.040, and it did the same for No. 2, which also slowed down tremendously. Strange, especially since the yeast chewed through a high-gravity belgian strong ale 2 years ago. I inoculated much more yeast at that time, and we did not aerate or add nutrients, besides the small amount in the boil (first time I used that). What I will do is add some more yeast next week (I have two 500 ml cultures growing right now).
The other cultures started tremendously slow, this morning all of them where fermenting more or less, except the pineapple yeast and No. 4. The two Brett strains from the Gueuze Cantillon were doing pretty good, some krausen was visible.
I also inoculated 500 ml cultures of these yeasts, to make sure that they will do what they should. Note to self, aerate and add nutrient, especially with these wild guys.
I bottled the saison and a mixture of pilsener, wheat and saison (I had 1.3 gallons of each which did not fit the carboy anymore) a few days ago, and they are already carbonated and delicious.
http://www.facebook.com/home.php?sk=group_209748835716347&view=photos
Beer
So Nick, Mark and Peter came by to measure the gravity of the wild yeasts and to do some tasting. Wild yeast one and two tasted great! Both definitely different, gravity was around 1.012 for both so we bottled those two. The other guys were not that far yet but the gravity had definitely sunk more, and the taste had dramatically improved compared to last time. Since they might be Brett (or any other wild yeast that can ferment more than good old cerevisiae strains) and the gravity had not sunk under the 1.012 for most of them, we will wait until they are more close to zero residual sugar and cleaner taste. In the mean time summer has started full blown and the temperatures in the garage are really high, how that will affect things we will see. Either way this is really turning into a success. Update soon!
