On the question of removing tomato skins, Iowa State Extension provides the following reasons applicable to canning:
“-Most tested recipes for tomato products were prepared and tested with skins removed. Therefore, the processing time is based on a peeled tomato unless stated otherwise. Skins may interfere with the necessary uniform heat penetration in the canning process resulting in under processing and an unsafe product.
-The skins of fruits and vegetables are sources of bacteria, yeasts, and molds. Some of these contaminants are removed when produce is washed with cool water, but removing it all is impossible. The bacterial load is reduced by peeling or slipping the skins, resulting in a safer final product.
-The texture of the skin may be undesirable in the finished product. Tomato skins do not break down well, often leaving chewy bits in the product.
-The flavonols in tomato skin impart a bitter taste.”
Thanks for sharing this recipe, Amy!
On the question of removing tomato skins, Iowa State Extension provides the following reasons applicable to canning:
“-Most tested recipes for tomato products were prepared and tested with skins removed. Therefore, the processing time is based on a peeled tomato unless stated otherwise. Skins may interfere with the necessary uniform heat penetration in the canning process resulting in under processing and an unsafe product.
-The skins of fruits and vegetables are sources of bacteria, yeasts, and molds. Some of these contaminants are removed when produce is washed with cool water, but removing it all is impossible. The bacterial load is reduced by peeling or slipping the skins, resulting in a safer final product.
-The texture of the skin may be undesirable in the finished product. Tomato skins do not break down well, often leaving chewy bits in the product.
-The flavonols in tomato skin impart a bitter taste.”
https://blogs.extension.iastate.edu/answerline/2023/07/18/peel-tomatoes-before-preserving/
The potential canning safety risks motivate me to peel tomatoes when canning, but I don’t bother when freezing whole or roasted.
I’ve really enjoyed reading your updates this summer. Thank you for sharing!
Thanks for this info. I have wondered if it was safe to can unpeeled tomatoes. Now I know the expert answer!