Based upon counts with a microscope and hemacytometer I pitched around ~130 billion cells into 23 liters of 12 plato wort. The beer is an APA and the yeast is WLP001. Based upon the ideal pitching rate of .75 million cells per ml * degree plato I should have pitched ~207 billion.
I pitched at 58 degrees and let the ferment rise under temperature control to 66-67 degrees over the first 24 hours. My temperature control allows me to hold the temperature within 1/2 degree. 24 hours after pitching high krausen had begun and at 72 hours I attached a blow off tube.
The fermentation has been far more active than previous batches of this APA with WLP001. I’ve got a nice amount of blow off. The only difference is a lower pitching rate, I added yeast nutrient and enough magnesium sulfate to get my brewing liquor to 10ppm. Blow off; in general is it a good sign or a bad sign?
On fermentation taking place, it is a good thing. ;D
On PPM of o2, I performed my usual treatment, 45 seconds of pure o2 through a stone for ales.
I saw an o2 meter on the website of the University Surplus store for $15 and thought about taking a chance. I’m sure it would need a new probe, but I haven’t looked into how much a replacement would cost.
The concern with lower pitching rates is yeast stress during fermentation. With the added stress comes the impact of undesirable beer flavors in the finished product. Eventhough you pitched cool you still needed over 200 billion cells to ideally ferment the beer.
I have roughly a gallon of headspace in the glass carboy. Fermentation is starting to wind down slightly and I believe the blow off is “over.” I raised the temp slightly to keep the yeast a bit more active. I’ll post tasting notes before dry hopping.
Actually I was kidding, I’m from the “let it be beer” school, and don’t worry be happy"… But I do add O2 with a stone as described above, and I think it helps, a lot. As far as the meter…go for it!