This article is from the Food Preserving FAQ, by Eric Decker firstname.lastname@example.org with numerous contributions by others.
A. What is the most similar USDA recipe? In this case, the Piccalilli
(p.18) is the reference recipe to use. Both the ingredients and the proced-
ures are similar. It does have green tomatoes, it does call for soaking the
vegetables in salt water and draining them, and it does call for simmering
them before packing. So, while the times are not quite the same, the next
step is to look at proportions.
B. What are the vegetable:acid proportions? With this recipe it is
not as simple as adding the quantities, because this one only specifies
numbers of peppers, etc., and not cups. Use the equivalencies table in fact
sheet (705) to estimate how many cups of produce it uses.
12 peppers; 9 peppers = about 3 C, so 12 = about 4 C
12 onions; 4 onions = about 3 C, so 12 = about 9 C
12 tomatoes; 3 tomatoes = about 1.5 C, so 12 = about 6 C
TOTAL VEGETABLES = 19 C
4 C vinegar
TOTAL ACID= 4 C
In the USDA recipe there are a total of almost 19 C of vegetables, but the
vinegar amount is 4.5 C.
Recipe: 19 C vegetables : 4 C acid
USDA: 18.75 C vegetables : 4.5 C acid
C. So, to correct the proportions, the acid must be increased at least
to 4.5 C, or better yet, to 4.75 C of vinegar. This recipe also has much
more sugar than the USDA recipe, so the increased vinegar might not be
noticeable. If it is the sugar may be increased as desired.
D. What recommendations can be made?
a. use 5% acidity vinegar
b. increase the vinegar from 4 C to 4.75 cups
c. mix the salt in, do not just sprinkle it on top
d. increase the time of soaking from 4 hrs to 12 hrs
e. increase the simmering time from 10 min to 30 min
f. use presterilized jars
g. process the filled jars for 5 min in boiling water
OR: h. use the recipe as is, do not seal, refrigerate the product