Important: Safety Warning

This page describes additives or treatments for food or drink that are now known to be toxic and are prohibited in food today.

In addition, this page boils fruit in an untinned copper pan to restore its green colour. The colour comes from dissolved copper salts, which are poisonous to eat, and the practice is prohibited in food production today.

This information has been left in for historical purposes but should not be acted upon.

No. 3680

Preserved Limes

Limons Confits

Remove the cores from the limes with a quarter-inch tin tube and leave them to soak in a pailful of water, adding a heavy handful of salt; let them remain four hours in this, then drain and throw them into a large basin of boiling water to blanch. As soon as soft take them up one by one and put into a pailful of cold water to refresh, changing it at frequent intervals. To have them turn green again, put ten quarts of water in an untinned copper pan, add two heaping handfuls of kitchen salt, half a pint of vinegar and a few handfuls of spinach; stand this vessel on the fire and boil for a few moments; drain the limes from their water and throw them into this while still in the act of boiling, allowing them to boil up several times. Take the basin from the fire and leave the fruits therein for three or four hours; they should now have assumed their natural color. Drain and plunge them into a pailful of cold water for twelve hours, changing it frequently during this time. Prepare a fifteen-degree syrup. As soon as it boils drain the limes and throw them into this, boil up once, then transfer the whole to vessels and leave in a cool place for twelve hours. The following day pour off the syrup and cook it to sixteen degrees, throw it once more over the fruits, leaving it for twelve hours; drain the syrup again, boil until it reaches twenty degrees, then pour it over the limes and leave for twelve hours longer, repeating the process every twelve hours until the syrup reaches thirty-two degrees, then pour it back into the basin and as soon as it begins to boil throw in the limes and boil up once. Transfer them immediately to their respective stone jars, cool and close hermetically.

← No. 3679 Preserved Greengages Preserves & Conserves No. 3681 Preserved Orange or Lemon Peel →

For the Modern Kitchen Do not make this as written.

This is a candied-fruit procedure from Delmonico's kitchen, and its central step is one that cannot be reproduced today. The reasons are chemical, not a matter of adjusted times.

The untinned copper pan is the whole problemBoiling fruit with salt and vinegar in bare copper is not incidental to this recipe; it is the mechanism. The acid attacks the metal and releases copper into the liquid, where it combines with the chlorophyll present in the peel and in the added greens to give a stable bright green. The "natural color" the text promises depends on dissolved metal in the fruit.
Copper salts are toxic, not merely unappetisingIngested copper compounds cause vomiting, abdominal pain and, at higher intakes, liver and kidney injury. A candied lime sits in syrup for days and is eaten whole, peel and all, so nothing is discarded and nothing dilutes the load. There is no safe quantity to aim for here because the recipe measures nothing.
Substituting a stainless pan does not rescue itWithout the copper the limes simply stay the dull olive-khaki they turn when blanched, and the remaining twelve-hour soaks and syrup stages are an ordinary candying schedule. If you want candied limes, use a current recipe rather than trying to repair this one.
On the "degrees"The syrup densities, fifteen degrees rising to thirty-two, are almost certainly Baumé readings taken with a saccharometer, the standard tool of a professional confectionery department in 1894. Thirty-two Baumé is a heavy syrup; the stepwise increase every twelve hours is what keeps the fruit from shrivelling.
"Close hermetically"In this period that would typically have meant sealing the stone jars with cork and wax or a bladder cover, relying on the sugar concentration rather than heat processing for keeping. It is not a substitute for modern canning practice.

A Little History

The Epicurean (1894) is Charles Ranhofer's record of thirty-odd years running the kitchens at Delmonico's in New York, and its preserves chapter reads like the notebook of a confectionery department working at scale — hence the pailfuls, the ten-quart pans and the saccharometer degrees. Artificially greening preserved fruit in bare copper was a long-established French practice, described in confectioners' manuals well before Ranhofer copied it into English, and it was already controversial: Frederick Accum's Treatise on Adulterations of Food of 1820 singled out copper-greened pickles and preserves as a danger to the public, and food chemists went on condemning the method through the rest of the century. That it still appears here, unqualified, in a book from one of the most celebrated restaurants in America says something about how slowly professional kitchen habit yielded to analytical chemistry — and about how much a cook of the period would sacrifice for the right colour on the plate.