Bingfen (Chilled Ice Jelly with Brown Sugar)

Variations

• With konjac: modern versions set konjac flour instead. It looks the same, but it is set by alkali and heat, and it chews firmer. The first tip below is about the seed version.
• Toppings are open: peanuts, raisins, goji, haw flakes, small rice balls, lotus seeds, melon — every stall differs. Names like san xian or lao tang refer to a particular set of toppings and syrup.
• Chinese block sugar instead of ordinary brown sugar carries more molasses. Use a little more water and melt it slowly.
• With ice: many stalls float ice in the syrup. Add it last and at the rim so the jelly is not diluted.
• Summer only: a Sichuan and Yunnan street food of hot weather, rarely sold in winter.

Tips

• Nothing in this jelly ever meets heat. Dotori-muk ties the starch jellies together in one line — "All three work the same way — one starch, water, and enough cooking.". The agar in tokoroten and yokan has to be boiled to dissolve, and the gelatine in panna cotta has to be warmed. Bingfen is rubbed out in cool water and sets at room temperature. Staying cold is a condition, not a convenience**: hot water will not release the mucilage at all, and warm syrup poured over the finished gel takes it apart again.
• What sets it is calcium, the same ion douhua uses on something else. That page states the principle: "Acid gives you lumps; a salt gives you a gel." In douhua the calcium bridges soy protein; here it bridges a pectin-like polysaccharide out of the seed. Same bridge, different railing — which is also why adding acid here does not give you curds as it would with milk or soy. It simply never sets.
• The rubbing is a cooking step. The mucilage sits on the surface of the seed and soaking alone barely releases it. Ten minutes of squeezing is what turns the water slippery, and that slipperiness is the concentration. Under-rub and it stays watery; over-rubbing costs nothing.
• Do not stir after the lime goes in. Douhua says the same of its own gel — "Once it is poured, do not touch it.** Move it during the twenty minutes the gel is forming and the network tears, and a torn network does not rejoin." Twenty seconds to mix it evenly, then leave it.
• But the temperature condition is the opposite of douhua's. That page has to hold a narrow window — "Around 85C. Hotter and it sets coarse and weeps; below about 75C it never firms." — while this one simply gets firmer the colder it is. A gel that is slack at room temperature will hold a spoon upright after an hour in the fridge. If it looks like a failure, wait before deciding.
• Cool the syrup before it is poured. Warm syrup melts the jelly from the edges in, and rushing step six is the commonest way this dessert collapses (serving temperature).
• Shave it with a spoon rather than cutting it. Cubes give square faces that syrup pools against; a shaved face is smooth, so the syrup runs off it and every spoonful brings up jelly, syrup and topping together.