Lemon Jelly

Wilson gives proportions and no method, which was normal for gelatin work in 1920 — the technique was assumed. Here is what the numbers mean and how they behave.

• Half a box of gelatinA box of granulated gelatin of this period, such as Knox, generally held four envelopes; on the usual reckoning half a box is about ½ ounce, or roughly two of today's standard envelopes, a little under 2 level tablespoons. Period equivalents vary, and some contemporary books make half a box nearer a scant ¼ cup, so the quantity is not certain.
• The set will be very softTwo envelopes reliably set about 4 cups of liquid; this recipe has 7 cups (1 pint juice, 2 cups cold water, 3 cups boiling water). Expect a spoonable jelly that will not unmould cleanly. For a moulded jelly firm enough to turn out, the gelatin needs to be increased or the water reduced.
• Order of operationsSoften the gelatin in the 2 cups cold water for five minutes, pour on the 3 cups boiling water and stir until no grains remain, dissolve the sugar in that, then add the lemon juice off the heat. Boiling the juice with the gelatin dulls the flavour and weakens the set.
• A pint of lemon juiceThat is roughly 11 to 16 lemons depending on size. Strain it; pulp and pith suspended in the jelly cloud it and turn it bitter as it stands.
• SugarOne and a half cups against a full pint of juice makes a sharp, almost sour jelly by modern taste. Taste the warm mixture before it sets and adjust — it will read as less sweet cold than it does warm.
• ChillingFour hours minimum in a shallow mould, longer in a deep one. Acid slows gelatin's set, and this is a highly acidic mixture.
• YieldAbout 7 cups, enough for 10 to 12 servings in glasses.
• Filed under VegetablesThe placement is a quirk of the book's arrangement, not a clue to the dish. This is a dessert or a salad base — set in a ring mould, it could be filled with fruit or dressed greens.