Important: Safety Warning
This page describes home-canning methods from before the causes of botulism were understood. Canning low-acid foods without a pressure canner, as described here, can allow the growth of Clostridium botulinum, whose toxin is among the deadliest known. Follow current USDA home-canning guidelines instead.
This information has been left in for historical purposes but should not be acted upon.
Home › Preserving › Tomatoes (Remove the skins)
Tomatoes (Remove the skins)
Remove the skins from the tomatoes and cut out the hard portion around the stem end.
Cook in a covered saucepan, shaking occasionally lest they burn, until hot throughout. Dispose boiling hot in hot jars, filling the jars to overflow; adjust rubber rings and covers, tightening the latter securely, and remove to a board. Avoid cooling in a draft, lest the jars be cracked.
Tomatoes No. 2 Peel small, ripe tomatoes and fill sterilized jars standing in a cooker or boiler. Have boiling on the stove tomatoes cooked as in the first recipe; use these to fill the spaces between the tomatoes in the jars, shaking the jars to fill all open spaces. Cover the large receptacle and let cook about fifteen minutes; adjust the rubber rings, fill the jars to overflow with some of the boiling hot tomato, set the lids in place, let cook ten minutes, then fasten securely.
Tomatoes, Canned Whole (New Style) If the tomatoes are small, leave them whole, simply peel and cut out the hard portion at the stem end. Larger tomatoes may be cut in quarters, preferably at the fleshy portion between the seed sections. Have the jars and covers thoroughly sterilized in boiling water; turn out the water and fill the jars as full as possible with the prepared tomatoes and adjust the rubber rings; set the jars in a large deep saucepan, or other receptacle, on several folds of cloth; turn a little boiling water into the dish against the cloth at one side, to temper the jars, then fill the jars to overflow with boiling water; adjust the covers (taken from boiling water), making them secure as when canning is finished; now pour boiling water around the cans to reach to at least half their height. Cover the receptacle and let stand until the jars are cold. The tomatoes when opened are about equal to the fresh vegetable.
These three methods are all versions of open-kettle and "cold-pack-without-processing" canning, techniques that were standard in 1914 and that every current canning authority has since abandoned. The problems are specific and they are not fixable by adjusting a time or a temperature.
- No processing to speak ofThe first method fills jars with hot tomato and seals them with no heat treatment at all after sealing. The third packs raw tomatoes, fills the jars with boiling water, fastens the covers and lets the jars stand in hot water until cold. Neither delivers a controlled, measured heat process to the contents of a sealed jar.
- Tomatoes are not reliably acidicTomatoes sit near the pH 4.6 line that divides acid from low-acid foods, and many modern cultivars, along with overripe or frost-damaged fruit, fall on the low-acid side. Current guidance requires added bottled lemon juice or citric acid in measured amounts per jar. These recipes add nothing.
- Botulism spores survive boilingClostridium botulinum spores are not killed at 212F. In a sealed jar of insufficiently acidified tomatoes they have an oxygen-free environment to germinate in, and the resulting toxin is not visible, does not smell, and is often not destroyed by a casual reheat.
- Sealing before heatingThe third method makes the covers secure before boiling water is poured around the jars, and the second sets its lids in place for the last ten minutes of cooking; closing up before the pack is heated through prevents air from venting and interferes with the vacuum that forms on cooling. A jar may seal convincingly and still be unsafe.
- "Equal to the fresh vegetable"The note at the end of the third recipe is the tell: raw tomatoes that taste raw when opened were never brought to a processing temperature. That was the selling point in 1914 and it is precisely the hazard.
- Obsolete closuresThe zinc- and glass-lid jars these rubber rings were made for are long out of production, and old rings perish. Modern two-piece lids are designed around a specified processing method, not around this one.
- What to do insteadCanning tomatoes at home is entirely practical, but use a current tested recipe with measured acidification and a specified boiling-water or pressure process. Treat this page as a document, not a procedure.
Home canning in the years before the First World War was a domestic economy project as much as a culinary one, and tomatoes were among the commonly put-up items in the American pantry, cheap in September and useful all winter. The "open-kettle" approach here, packing boiling food into hot jars and sealing at once, was the orthodox method of the period; the fussing over drafts and cracked glass reflects real anxiety about thermal shock. The third variant, labelled "New Style," was part of a fashion for cold-pack canning that promised produce tasting closer to fresh, and it shows how far the emphasis lay on flavour and appearance rather than on sterility. Systematic study of jar temperatures, food pH and the survival of botulinum spores came later, largely through agricultural extension work in the 1920s and after, and it gradually retired this whole family of methods.