Fermentation
Molasses makes a good base for fermentation.
In fact, most of the yeast produced in the world
is made using a molasses substrate. However
there are several potential problems with
molasses that must be considered if fermentations
are to be efficient and cost-effective.
The amount of fermentable sugar varies greatly
in molasses. In order to standardize, yield
calculations are usually based on 55% sugars.
A good fermentation with high quality molasses
should yield about 290 liters of ethanol per ton
of molasses. However recent molasses
shipments have yielded more on the order of
260 liters/tonne. Molasses prices are set
internationally; and typically run $USD35-40 per
ton FOB with freight added raw material cost
per liter of alcohol can be $0.20-0.25.
With the increasing efficiency of the sugar
industry in extracting sugar, the molasses
remaining for use in fermentation/distillation
operations is becoming poorer in quality. Some
plants are finding it necessary to sterilize and