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Vegetable Essences, to Extract
The flavour of various herbs may be extracted as follows. Pick the leaves, and put them in a warm place for an hour or two. Fill a large wide-mouthed bottle with them, and pour upon them wine, brandy, spirits of wine, or vinegar. Let them soak for a fortnight. Strain the liquor, and put it into small bottles for use.
A general method rather than a single recipe: it is the standard Victorian way of making herb vinegars and flavouring essences, and it still works. Two details in the wording need translating before you start.
- "Spirits of wine" is not methylated spiritSpirits of wine meant rectified spirit, a strong plain ethanol, commonly around 90 per cent or higher. Modern products with similar names — methylated spirit, surgical spirit, denatured alcohol — are deliberately adulterated with denaturants, methanol among them in some formulations, and must not be drunk. For an edible essence use a food-grade neutral spirit of the highest proof you can buy, or simply vodka.
- The hinge: wilt, do not dry outThe "warm place for an hour or two" drives off surface water so the infusion is not diluted and does not spoil. Spread the leaves in a single layer somewhere warm and airy until limp but still green and fragrant. Wet leaves straight from washing will cloud a vinegar and can push an alcohol infusion below the strength that keeps it.
- ProportionsThe original simply fills the bottle with leaves and covers them, so no fixed ratio is given. Press the leaves down and make sure everything stays submerged; anything standing proud of the surface will discolour and go musty.
- A fortnight is for tough herbsRosemary, thyme, sage, bay and tarragon stems take the full two weeks. Basil, mint, chervil and dill give up their flavour in three to five days and turn grassy and bitter if left longer. Taste from the fourth day and strain when it tastes right.
- Vinegar behaves differently from spiritAlcohol pulls out the aromatic oils and holds them; vinegar extracts more slowly and its own acidity dominates the result. Use wine vinegar rather than malt, and glass or plastic-lined caps — vinegar corrodes bare metal lids.
- Straining and storingStrain through muslin, then let it settle and decant off any sediment. Fill the small bottles to the neck, cork or cap tightly, and keep them dark. A spirit essence keeps a year or more; a herb vinegar is at its best within six months.
- How much you getExpect noticeably less finished essence than the volume of liquid you pour in, since the leaves soak up a good deal of it. Alcohol essences are used by the few drops, so bottle them in something small with a good closure.
This entry describes a technique borrowed from the apothecary: steeping plant material in spirit and straining it is the making of a tincture, and Victorian kitchens and dispensaries used much the same jars, timings and muslin. Herb vinegars were the older and more domestic branch of the practice — tarragon, elder-flower and cucumber vinegars appear in eighteenth- and nineteenth-century English receipt books — while spirit-based essences were valued by cooks because a few drops flavoured a sauce without thinning it. The whole business belongs to a period before reliable year-round supply of fresh herbs, when the summer garden had to be bottled in some form if it was to be tasted in February; the same impulse produced dried herb bundles, herb butters and potted and salted preserves.