mother-in-law used to can eggplant. I was wondering if
the process she uses is safe, as she has recently passed
away. I think it is safe because we ate it and never got
ill. I have her recipe, but I find it strange that there
is no heat processing.
The recipe says to slice eggplant paper-thin and
layer with salt into a pan. Place a plate and a weight
on top of the eggplant and allow it to sit over night on
counter top. Next day, drain drippings from pan and fill
with vinegar and allow to sit overnight. Layer slices
with olive oil, garlic, red pepper flakes in a mason
jar. Seal the jars.
She never refrigerated the jars until opened. She used to put them in the basement and sometimes didn't open them for years.
The salting and vinegar steps would prevent the growth of Clostridium botulinum since the bug is sensitive to pH and salt and decreased water. This product is a good example of what we call the "multiple hurdle" concept. Probably none of the control techniques is sufficient in itself, but the combination of the three make it very unlikely that the bug can grow.
Layering with oil then prevents oxidation. It is
probably a safe recipe, but not one that we can
recommend until we know several more things such as
sodium content, water activity, and equilibrium pH.
Source: Douglas Holt, Ph.D., Chair
of Food Science Program & State Extension Specialist for
Food Safety, University of Missouri-Columbia
Last update: Tuesday, May 05, 2009