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Tomato Preserve
Select small, half-ripe or green tomatoes.
The small yellow, pear-shaped tomatoes are often selected for this purpose. Remove the stems carefully but do not cut or injure the fruit.
Weigh the tomatoes and take three fourths a pound of sugar to each pound of tomatoes.
Allow a lemon for each two pounds of tomatoes.
Cut the lemons in very thin slices and let cook in water until the skin is very tender. Strain off the water; use this water and as much more boiling water as is needed to make a cup of liquid to each pound of sugar. Let cook to a thin syrup; add the tomatoes and slices of lemon and let cook until the tomatoes are heated through. Skim the tomatoes and lemon; put in jars; let the syrup boil till well-reduced, then pour over the tomatoes. Ginger root may be cooked with the lemon slices.
This is a sugar preserve written for an era when a filled, capped jar was considered finished. It gives no processing step, and tomatoes are the one fruit where that omission matters.
- No heat process at allThe tomatoes are only "heated through," then skimmed into jars and covered with reduced syrup. Nothing here brings the sealed jar to a temperature that destroys spores, and the recipe names no boiling-water bath, no processing time, and no jar or closure standard.
- Tomatoes sit on the acid borderlineTomato pH is usually reported in the region of 4.0-4.6, varying with variety and ripeness, and some ripe fruit tests above 4.6, the line that separates foods safe in a boiling-water bath from those needing pressure processing. Green and half-ripe fruit as called for here tends to be more acidic, but the value cannot be known without testing. Modern tested recipes for tomato preserves specify added bottled lemon juice or citric acid in measured amounts for exactly this reason; the lemon slices here are flavouring, not acidification, and their contribution cannot be calculated.
- Whole fruit, not crushed or cooked downThe tomatoes are deliberately left uncut and uninjured. Heat penetrates a sealed whole fruit slowly and unevenly, so even a jar that looks hot throughout may have a cool interior in the fruit itself.
- Syrup added separatelyBoiling the syrup down after the fruit is jarred means the jar contents are at two different temperatures and the pack is never held hot as a unit. This is the opposite of the hot-pack logic modern canning depends on.
- The sugar is not high enough to preserve on its ownThe sugar is likely not high enough to preserve on its own -- Three-quarters of a pound of sugar per pound of fruit, then diluted with a cup of water per pound of sugar, gives a soft syrup rather than the water-activity-lowering concentration of a stiff jam or candied fruit. The syrup is boiled down before it is poured over, which concentrates it by an amount the recipe never fixes, so the final sugar level is unknown and should not be relied on to hold the pack at room temperature.
- Botulism gives no warningClostridium botulinum in a sealed, under-acid, under-processed jar produces no off smell, no bubbling and no visible spoilage in many cases. Unlike mould or fermentation, there is nothing to inspect for.
- If you want the dishUse a current tested recipe for green tomato or yellow pear tomato preserves from a reputable extension service, with its stated acidification and processing time. Do not adapt this text.
Small yellow pear tomatoes were a fixture of nineteenth-century American kitchen gardens, and they were commonly treated as a preserving fruit as much as a salad vegetable — put down in syrup, candied, or made into what was sold as "tomato figs." Sweet whole-fruit preserves of this kind belong to a genre that also took green gages, damsons and unripe grapes: firm, underripe fruit that would keep its shape in syrup, brightened with lemon and sometimes ginger root, as here. The recipe's silence about sealing and processing is typical of preserving instructions before the twentieth-century home-canning research programs, which established that tomatoes sit close enough to the acid borderline to need measured acidification and timed heat rather than a cook's judgment.