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.

No. 830

Truffles

Truffes

Select those that are small and very round, brush over, and peel. Set them in a saucepan with two ounces of butter, salt and nutmeg, and place them on the fire for a quarter of an hour, being careful to watch that they do not boi'.; a little fire can also be placed on the cover; then drain and arrange them in a glass bottle filling it with Aix oil, and closing hermetically. To serve truffles, drain them off, dress, and to the oil add a little lemon juice.

← No. 829 Trout Marinated in Wine-Small Cold Side Dishes No. 831 Marinated Tunny Fish, Sardines, Gurnet and A →

For the Modern Kitchen Do not make this as written.

Ranhofer is describing a nineteenth-century larder technique: barely cooked truffles sealed under oil and kept in a bottle until wanted. The preservation step is the part that has not survived scrutiny, and it is the reason this page is worth reading rather than cooking.

Why it fails: mushrooms under oilTruffles are a low-acid food carrying soil bacteria, including spores of Clostridium botulinum. Covering them with oil in a hermetically closed bottle creates exactly the oxygen-free environment those spores need to germinate and produce toxin, and nothing in this method — no acid, no measured heat, no refrigeration — prevents it.
The heating step is not a kill stepFifteen minutes in butter with the explicit instruction that they must not boil keeps the truffles well below any temperature that would destroy botulinum spores. It is a flavouring and softening step, and Ranhofer never claims otherwise; the text gives no indication of how the bottles were stored or how quickly they were used.
No storage guidance at allThe original gives no temperature and no time limit. Vegetables in oil are now treated as a refrigerated, short-life product with an acidification step, made to a tested formula. A recipe that omits both quantity of acid and holding temperature cannot be brought into range by guesswork.
Commercial truffle products are not the same thingJarred truffles on sale today are retorted under pressure at temperatures far above boiling, and truffle oil is generally oil flavoured with 2,4-dithiapentane rather than oil containing truffle. Neither process is reproducible from this text.
Aix oilOlive oil from Aix-en-Provence, which had a reputation in the period as a fine oil. Here it is used as the preserving medium that fills the bottle.
"A little fire on the cover"Live coals placed on the lid of the saucepan, so heat came from above as well as below and the truffles cooked gently through without the base scorching or the liquid reaching a boil. The modern equivalent of the intent is very low, even heat, not an extra heat source.
If you want to serve trufflesUse a current, tested recipe for preserving vegetables in oil, or buy commercially processed truffles. The finishing note here — draining them, dressing them, and sharpening the oil with a little lemon juice — is sound and belongs to the serving, not the preserving.

A Little History

The Epicurean (1894) is Charles Ranhofer's account of thirty-odd years as chef at Delmonico's in New York, and it reads as a working reference for a brigade rather than a book for a household cook. Truffles appear throughout it in quantities that now look extravagant, turning up sliced into sauces, studded under poultry skin, and here treated as a preserved store item to be drawn on through the season; the recipe itself names no variety. Bottling under oil is one of the oldest ways of holding a delicate ingredient past its few winter weeks. The instruction to choose truffles that are small and very round is about the finished dish as much as the jar: these were served whole as a cold side dish, one of the many small dressed items that filled out a long Delmonico's menu.