This article is from the Food Preserving FAQ, by Eric Decker firstname.lastname@example.org with numerous contributions by others.
Evaluating Home Canning Recipes For Safety
What do you do when someone gives you "Aunt Tillie's Special" old favorite
jam recipe? Or Uncle Willie's barbecue sauce? Or Cousin Millie's dill
pickle recipe? In today's heightened awareness of food safety, how do you
tell which are safe and which are not? There are no hard and fast rules, or
secret formulas, to help you decide. But there are some priorities you can
use to help you balance the pros and cons. They depend on the factors that
molds, yeasts and bacteria need to grow, and on the relative hazards that
molds, yeast and bacteria present in foods.