Green peppercorns, photo used with permission from macinate's photostream
I get all the updates on food recalls by the USDA, sometimes several a day. I seldom post them anymore because all that does is dwell on the negative.
However, I just recently noticed something I had not previously considered. A couple of huge batches of salami, Italian sausage, pepperoni, etc. were recalled for salmonella contamination, and it seems the culprit may be the peppercorns used in the spicing. I thought that would be almost impossible... aren't peppercorns machine-dried which entails heating?
Photo used with permission from exfordy's photostream
So I did some research. What turns the pepppercorns black is fermenting, the first step after harvesting. Traditionally the spikes are threshed and the ripe berries left overnight at room temperature to begin a simple fermentation. Depending on the drying process, the fermenting continues through the drying process.
Alternatively, the berries can be steam blanched to deactivate the enzymatic reactions in the pepper to speed the fermentation.
Traditional drying (rather than mechanical) is still done in many countries around the world. Usually the berries are placed on mats in the sun for about 4-5 days, until the moisture content is reduced to about 10%. You can also use a solar dryer, or even a tray-style dryer. The draw-back to air drying is the increased risk of contamination, so sorting must be done carefully.
In machine processes, sterilization is done just before packaging. Some processing plants use a steam process where the peppercorns flow through a steam container. This is not true sterilization. True sterilization requires a certain amount of time at prescribed temperatures and pressure to kill the microbes.
However, salmonella does not ever originate from the peppercorns themselves. Salmonella bacterium live in the intestines of birds, reptiles and mammals (including humans), and can contaminate our foods by transmission from animal and human feces due to unsanitary conditions, or even by bird droppings on air-drying peppercorns. Someone who has had salmonella exposure can unknowingly be a carrier for up to a year.
So when you purchase peppercorns, do so from a trustworthy processor. Bulk peppercorns may come from a reputable vendor like Frontier Herbs (mine do, via my natural food stores), or they may come from purveyors of imported and unknown origin goods at the wharves.
There's lots more to know about various peppercorns and flavoring techniques, but that's for another day.