This article is from the Food Preserving FAQ, by Eric Decker firstname.lastname@example.org with numerous contributions by others.
A. The procedures in this recipe are so different that there are no
USDA recipes to use for reference. It can not be considered safe.
B. Explanation and analysis:
When the juice is removed from tomatoes by mechanical means
(squeezing, ladling off the clear liquid) the acid balance is changed. With
the juice removed, it will take less time for the sauce to become thick when
it is cooked. But, that means that there is less cooking time to kill bac-
teria and mold spores. Also, because it is thicker the heat will penetrate
and kill the spores more slowly. So, the product going into the jar has a
greater likelihood of still having live spores present. And, if it were
processed, because it is thick, it would need more than the usual process
time to kill them.
C. The only recommendation that can be made with a recipe of this
type is to refrigerate the product without sealing, or freeze it. It can not
be canned safely.