Tremella (Snow Fungus) Gel
What it is
Tremella fuciformis — snow fungus, silver ear, white fungus (Chinese yín'ěr 银耳 or xuě'ěr 雪耳) — is an edible gelatinous fungus that, when simmered, releases polysaccharides that thicken the cooking liquid into a natural, slippery, gently gelled syrup. It is the basis of Chinese sweet soups (tong sui) prized as a nourishing "beauty food," giving a soft, gelatinous, lubricating mouthfeel without any added gelling agent.
The science
The gel here comes not from animal collagen or seaweed but from the fungus's own cell-wall polysaccharides — chiefly the heteropolysaccharide often called tremella polysaccharide (an acidic glucuronoxylomannan). The dried fungus, when rehydrated and simmered for a long time, swells enormously and progressively releases these long-chain polysaccharides into the liquid, where they raise viscosity and form a soft, mucilaginous gel — the liquid turns silky, slightly thick, and clings to the spoon, with the fungus itself becoming tender and slippery-crisp. The polysaccharides are water-binding and remain stable through cooking; the texture is a gentle thickening-to-soft-gel rather than the firm set of gelatin or agar. These same polysaccharides are the reason tremella is studied for water-binding (hence the "beauty"/skin-hydration reputation) and other bioactive properties, and they give the soup its characteristic body.
How it's done
Soak the dried snow fungus in water until it swells and softens (it expands several-fold), then trim away the firm yellowish core/base. Tear into small florets and simmer gently in plenty of water — often for an hour or more — until the fungus is soft and the liquid has thickened and turned slightly gelatinous; long, slow cooking extracts the most polysaccharide and the silkiest result. Sweeten with rock sugar and typically cook with companions: dried longan, goji berries, red dates (jujube), lotus seeds, lily bulb, or pear. Serve warm or chilled; chilling firms the gel slightly. Modern pressure-cooking shortcuts the long simmer.
When to use it
When you want a soothing, naturally gelatinous sweet soup or dessert with a slippery, nourishing body and a delicate texture — the classic Cantonese and broader Chinese tong sui, especially served as a restorative or "beautifying" dish. Choose tremella when you want a plant-based, traditionally medicinal gel-soup whose texture comes from the ingredient itself rather than an added setting agent, and where the soft, drinkable, lightly gelled consistency (not a firm sliceable gel) is the goal.
What goes wrong
Not soaking and trimming the tough core leaves hard, unpleasant bits. Under-cooking leaves the fungus rubbery and the liquid thin, with little of the desired gelatinous body; the silkiness only develops with sufficient simmering. Over-rapid boiling can be used to extract gel faster but risks a less refined texture. Using too little fungus or too much water gives a watery, un-gelled soup. As with all dried fungi, sourcing matters — quality snow fungus gels and softens far better than tough, low-grade product.
Regional & cultural variations
Snow fungus is a pillar of Chinese tong sui (sweet soup) culture, especially Cantonese, where yín'ěr tāng (snow fungus soup, often with rock sugar and pear or red dates) is a beloved home and restaurant dessert. It also appears in savory soups and stir-fries (where its crisp-slippery texture is valued) across Chinese regional cuisines. In traditional Chinese dietary therapy it is classed as cooling and nourishing to the lungs and skin — historically a luxury tonic, once reserved for the wealthy and even imperial tables before cultivation made it affordable. Related gelatinous fungi (wood ear, Auricularia) are used more in savory dishes for texture.
Cultural & historical context
Tremella has been esteemed in China for centuries as both food and medicine, long associated in folk and court tradition with beauty, longevity, and respiratory health, and famously reputed (in popular history) as a delicacy favored by imperial consorts. Once a rare and costly wild-harvested ingredient, it became widely accessible after methods for cultivating it were developed in the 20th century, transforming a luxury tonic into an everyday dessert ingredient across the Chinese-speaking world.
Reference notes
A naturally-occurring polysaccharide gel — cross-link to Agar and Pectin (fellow plant/polysaccharide gels) and contrast with animal Gelatin, since tremella delivers a "gelatinous" mouthfeel with no animal product, making it a natural fit for vegetarian and traditional-medicine contexts. Connect to tong sui / Chinese sweet-soup culture, to companion ingredients (rock sugar, red date, goji, lotus seed, lily bulb, pear), and to Chinese dietary therapy (shíliáo). Compare with wood-ear fungus for savory textural use.