I've compared the average daily temperatures of St. James Parish, Louisiana, to different conditions for making Perique. 37°C is considerably higher than that. When you start with tobacco leaf that is contaminated with all the things (dirt, fungi, bacteria, debris) that inhabit a growing field, the challenge is not so much that of finding the ideal temperature for
Pichia anomala growth, but rather the temperature at which
P. anomala can out-compete all the other microbes.
Escherichia coli (
E. coli) is a common competitor, is the organism that seems to initially predominate, and that creates the fecal odor often noted during the earliest weeks of Perique fermentation. In situations where the temperature remains high (say, 37°C, which is like tucking the Perique press under your armpit for 3+ straight months), as in a Kentucky tobacco barn in mid summer, that fecal odor can become stubbornly persistent.
My best batches of Perique were made over the
winter, hidden from direct sunlight, on my enclosed back porch, which is open to the interior heating of my house. The porch usually stays a bit warmer than the house in the summer, and a bit colder than the house in the winter.
[NOAA]
Displayed in °F. St. James Perique is initiated using minimally color-cured leaf (so, early autumn), and undergoes most of its fermentation over the winter months in an unheated structure. That would range from ~5°C to maybe 30°C.
The relatively anaerobic pressing conditions, along with more moderate temperatures, appear to allow the yeast (
P. anomala) to out-compete the
E. coli. I've never tested my notions in a laboratory setting, so it is all conjecture. Do the conditions need to be just like in Louisiana, where they had no choice in the matter? I don't know.
Bob