Lemon Posset for Two or Three

Ingredients

• 200 ml Double cream, about 45 to 48% fatBuy the carton labelled double cream (often sold as rich or thick double cream) and check the fat on the label. Ordinary 35% thickened cream is not automatically equivalent and may set softer or not at all; never use light cream, low-fat cream or milk. Milk allergen.
• 67 g Caster sugarThe source uses golden caster sugar.
• 25 ml (about ½ to 1 lemon) Lemon juice, freshly squeezed
• Zest of 1 lemon (about 1 teaspoon, 5 ml) Finely grated lemon zestWash and dry the lemon first; grate only the yellow skin.

Yield: Makes 2 to 3 small cups in this adaptation. Source facts, for the posset only: serves 6; 600 ml double cream, 200 g golden caster sugar, zest of 3 lemons and 75 ml lemon juice; dissolve the sugar over gentle heat, simmer 1 minute, stir in zest and juice off the heat, divide between pots, cool to room temperature, cover and chill for at least 3 hours or up to 24 hours. The source's listed prep and cook times include its shortbread, so they are not repeated here. Our arithmetic: all amounts divided by 3 — 600 ÷ 3 = 200 ml cream; 200 ÷ 3 = 66.7, rounded to 67 g sugar; 75 ÷ 3 = 25 ml juice; 3 ÷ 3 = zest of 1 lemon. Times in this record (editorial): active about 10 minutes; cook about 5 minutes; cool 30 to 45 minutes; chill at least 3 hours (source); total at least about 4 hours. Chilling is waiting time, not prep time. Storage: keep covered in the fridge and eat within the source's 24-hour window.

Method

1. Tools: a small heavy-based saucepan (about 1 litre), a fine grater, a citrus juicer, a measuring jug, a heatproof spoon or spatula, and 2 or 3 heatproof glasses or ramekins of at least 150 ml each. Zest the lemon, then juice it and measure out 25 ml.
2. Put the cream and sugar in the saucepan over low heat and stir until the sugar has completely dissolved and you can no longer feel grains on the spoon.
3. Turn the heat up a little and bring it to a gentle simmer, then let it bubble for 1 minute, stirring, as the source directs. Watch it closely: cream can rise and boil over quickly.
4. Take the pan off the heat and stir in the lemon zest and juice. The mixture thickens slightly straight away.
5. Pour it into the glasses. Let them cool to room temperature, about 30 to 45 minutes, but no longer than about an hour; then cover and refrigerate.
6. Chill for at least 3 hours, as the source says, until set: the surface should be firm enough that the posset barely moves when you tilt the glass. If it is still liquid after the full chill, give it more time in the fridge and check that the cream fat level, measured lemon juice and simmer matched the instructions; fat level is not the only possible cause.