Halva — The Tahini That Sets and the Marble That Tells You How

Ingredients

• 500 g raw sesame tahini, not roasted; highest oil content available, freshly made if possible
• 300 g caster sugar
• 50 g glucose syrup, to inhibit crystallisation
• 100 ml water, for the syrup
• 15 g soapwort root extract (erq al-halawa), dried root of Saponaria officinalis; or commercial saponin-based halva foaming agent
• 150 ml water, for boiling the soapwort extract

Method

1. 1
   Simmer the soapwort root in 150 ml water for 20 minutes, then strain and discard the root, allowing the liquid to cool to room temperature before beating — if you whip it hot it will not hold its structure. Beat the strained liquid vigorously by hand whisk or stand mixer until it forms a dense, stiff white foam that holds its peaks and does not collapse when the whisk is lifted. The foam is ready when it is opaque and will not flow.
2. 2
   Combine the sugar, glucose syrup, and 100 ml water in a heavy saucepan and bring to the boil over medium heat without stirring, so no premature crystals form at the edges and cloud the syrup. Cook, monitoring with a calibrated sugar thermometer, until the syrup reaches 125–130°C — below 125°C the halva will be soft and sticky, above 130°C it will be brittle rather than fudgy-crumbly. Remove from the heat the moment the thermometer reads 128°C.
3. 3
   Pour the measured tahini into a wide bowl and stream the hot syrup into it in a slow, steady pour, folding continuously with a wide spatula so the heat distributes evenly and the mixture does not seize into lumps. Do not stir in circles, which would deflate the soapwort foam you are about to add. Fold until the syrup is fully absorbed and the mixture is uniform in colour and viscosity — it will be warm, fluid, and glossy.
4. 4
   This is where the dish lives or dies. Working quickly while the tahini-syrup mixture is still warm and fluid, add the soapwort foam in two additions, folding each in with the absolute minimum number of strokes needed to distribute it, so the foam's micro-voids survive into the finished mass and give halva its characteristic faintly fibrous, crumbling texture rather than a dense, greasy slab. Fold, do not stir: each unnecessary stroke collapses structure that cannot be recovered. The finished mass should appear slightly lighter in colour than the raw tahini, with a faintly marbled, streaked surface showing where foam has been incorporated but not fully erased.
5. 5
   Pour immediately into a lightly oiled loaf tin or square mould, then draw a spatula or skewer through the surface in two or three slow passes to produce the characteristic swirl — the pattern should remain distinct as two colours, yet partially merged enough to show integration, since a completely unmixed two-colour surface means the mass was poured too cold. Set at room temperature, uncovered, for a minimum of four hours. Do not refrigerate, as cold setting suppresses the micro-voids that give halva its character.
6. 6
   Unmould when fully set and break a small piece from one end to read the texture: it should crumble with slight resistance, producing irregular fragments with a faintly fibrous internal structure visible at the break, whereas a clean, smooth break tells you the foam was insufficiently incorporated. Held on the tongue, the halva should begin to melt at body temperature, releasing sesame oil and sweetness in approximately equal measure.