Meats preserved in wine become dry and nourishing: they dry out because of the wine; they are nourishing because of the flesh. Preserve din vinegar, they ferment less, because of the vinegar, and are quite nourishing. Meats preserved in salt are less nourishing, as salt deprives them of moisture, but they become lean, dry out, and are sufficiently laxative. Hippocrates, On Regimen in Acute Diseases
A few days ago, contemplating some minutiae or other on French culinary history, I came across some Meyer lemons in my local Kroger. Now for those of you living in California or a food-buyers’ paradise like New York City, you’re probably thinking, “What’s the big deal?” The big deal is that I rarely see these beauties nestled next to the regular lemons, hard and unforgiving in stringy bags. Meyer lemons resemble the Moroccan lemons I remember from when I lived in Rabat. In fact, Paula Wolfert recommends using Meyers to make preserved lemons.
And that’s the point: cooks in France now find preserved lemons in many places other than the plastic or stoneware vats in theBellevillemarket or other markets catering to the immigrant population from North Africa.
A testimony to the ancient practice of preserving food by using salt, and lots of it, preserved lemons end up in many tagines and salads. Kitty Morse, an expert on Moroccan food, describes how to make these golden orbs, perfumed with spices and the sweet smell of lemon oil. So I decided to load up my Meyer lemons with salt and spices and turn them into the new staple of French cuisine. I hoped that the flavor would remind me of Morocco, where the market stalls constantly displayed fresh fish and sweet ripe fruit that I rarely ever saw in the United States.
By adding salt to these lemons, you’ll be following the deft motions and ancient knowledge of generations of cooks: utilizing lactic-acid fermentation to preserve food. In France, sauerkraut (as well as turnips) – represents one of the major foods preserved this way and some farms in Alsace and Franche-Comté still follow the age-old procedures.
Lactic-acid fermentation begins with pyruvic acid, the product of glycolysis or the breakdown of glucose. To get technical about it …
Lactic-acid fermentation occurs in a two-step process. First comes anaerobic glycolysis, until pyruvate forms. Then – depending upon which substrates and acceptors are available, as well as environmental conditions – pathways change. Lactic-acid fermentation is generally carried out by anaerobic bacteria and yeast.
There are two types of lactic-acid fermentation:
Glucose is converted to pyruvate and this produces two lactic acid molecules, thanks to the presence of the enzyme lactate dehydrogenase.
C6H12O6 → 2 CH3CHOHCOOH
This process uses pyruvate to produce byproducts – lactic acid, ethanol and carbon dioxide - with the aid of the enzymes lactate dehydrogenase and pyruvate decarboxylase.
C6H12O6 → CH3CHOHCOOH + C2H5OH + CO2
Lemons, being rich in the anti-scorbutic vitamin C, may even carry this vitamin level over to pickled lemons, a term which more or less describes preserved lemons, because they are similar in concept to the lemon pickle of India. Heat denatures vitamin C, but since you’re not doing any cooking when you make preserved lemons, it is likely that preserved lemons render up a significant amount of vitamin C. Studies show that vitamin C levels of citrus peel is quite high,* though generally this is not available to you because, if you’re like me, you usually toss in the garbage, along with the seeds.
Besides the usual tagines and salads, you can use preserved lemons (or confit de citron) in French cooking in many ways. What about adding chopped preserved lemons to French lentils? Or to traditional Provençal braise of rabbit with olives? How about substituting preserved lemons for cornichons in some recipes, like Pork in the Style of the Butcher’s Wife? Even the latest English-language version of the staid Larousse Gastronomique suggests cooking sea bream with preserved lemon and actually provides a recipe for preserved lemons (p. 608, 2009). [Note that the 1960 English-language edition of the Larousse Gastronomique mentions Preserved Lemon Peel (écorce de citron confite or citronnat), but these taste sweet.]
Other French foods that exist because of fermentation (not always lactic acid):
Fish – anchovies, garon/garum (Bruyerin)
Rilletes or potted meat, confit
To Make Preserved Lemons
Take a sterilized jar with a tight-filling lid, also sterilized. Wash and dry your Meyer lemons (you can use regular lemons, but the taste won’t be as nice); snip off the stem end to remove the remnants of the stem, turn the lemon to the other end and make deep cuts down toward the stem end, like you’re cutting a cross into the end of the lemon. Rub about a tablespoon of Kosher salt into cut and stuff the lemon into the jar. Repeat with all your lemons, pushing the lemons down to extract juice. sprinkle in another couple of tablespoons of salt and if you wish some black peppercorns, a cinnamon stick, some coriander seeds, and a bay leaf. You may have add some freshly squeezed lemon juice to cover the lemons, but they keep popping up, so it’s hard to tell how much to add. More is better than less. Seal the jar and let the lemons sit over night on the kitchen counter. The next day, press the lemons down again. Repeat the next day if necessary. Then just leave them to sit for about a month. To use, cut away the pulp and use the softened rind. Refrigerate the lemons at this point.
*Nagy, Steve. “Vitamin C content of citrus fruits and their products.” American Chemical Society 28 (1): 8 -1 8, 1980.
© 2011 C. Bertelsen