Tomatoes can be preserved by freezing, canning, or drying with good results. For best results, remove the skins of all varieties of tomatoes before preserving them.
Removing tomato skin, sometimes called peeling or skinning, means removing the outer covering or skin from a fruit or vegetable, usually with a knife—like peeling an apple or a potato. My grandma said, ‘slip the skin,’ which seems more appropriate for removing the skin from a tomato. The process is simple:
- Dip tomatoes in boiling water for 30 to 60 seconds until the skins split or wrinkle.
- Dip into cold water, slip off the skins, and remove the cores.
It is recommended that the skin of all varieties of tomatoes be removed before canning, including cherry tomatoes. If you have a lot of tomatoes and time is short, they may be frozen with skins on (or removed). When the tomatoes are thawed, the skins will slip right off. Tomatoes that have been frozen and thawed may be used in place of canned tomatoes in any recipe or canned following a tested recipe.
Removing the skins is important for these reasons:
- 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 underprocessing 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.
So bite the bullet and slip those tomato skins. While skinning the tomatoes might take time, it is an important step when canning tomatoes. That extra time ensures that the product is safe to consume when the jar is opened and tastes good.
For more information on freezing, canning, and drying tomatoes, check out How to Preserve Tomatoes and Preserve the Taste of Summer, Canning and Freezing Tomatoes. When canning tomatoes or tomato products, remember to acidify with commercially bottled lemon juice or citric acid to prevent the possibility of botulism.
Updated 8 June 2023.
Sources:
- USDA Complete Guide to Home Canning, Bulletin No. 539. 2015.
- Cherry Tomatoes #207814, Ask Extension
