Clear noodles, often called glass noodles or cellophane noodles, are made from vegetable starch and water. The most common starch source is mung beans, but sweet potato, pea, and tapioca starches are also widely used depending on the country of origin. Unlike wheat noodles or rice noodles, clear noodles contain no grain flour at all, which is what gives them their distinctive translucent, glassy appearance once cooked.
The Main Starch Sources
Mung bean starch is the traditional and most common base for glass noodles, particularly in Chinese cooking. The starch is extracted from dried mung beans, yielding a fine white powder that becomes nearly invisible when hydrated and cooked. These noodles are sometimes labeled “bean thread noodles” or “cellophane noodles” at grocery stores.
Korean glass noodles, called dangmyeon, are made from sweet potato starch instead. They tend to be slightly thicker and chewier than mung bean versions and are the noodle used in japchae, a popular stir-fried dish. Sweet potato starch noodles also hold up better in longer cooking times, which is why they’re a go-to for hot pots and braises.
Other varieties use pea starch or tapioca starch, though these are less common. The starch source changes the texture slightly, but the basic recipe is the same: pure starch plus water, shaped into strands.
How They’re Made
The production process is simpler than you might expect. Hot water (at least 90°C, or near boiling) is mixed into the starch to form a dough. The ratio is roughly equal parts water and starch by weight. This hot water step is critical because it partially activates the starch granules, giving the dough enough structure to hold together.
The dough is then pressed through an extruder or rolled into thin sheets under vacuum conditions to remove air bubbles. Air pockets would make the noodles cloudy and fragile, so removing them is what produces that signature clarity. The sheets are then steamed to fully cook the starch, cooled to let the starch firm up (a process called retrogradation), and finally cut into thin strands. Many traditional producers freeze and thaw the noodles before drying, which further strengthens the texture.
Nutritional Profile
Glass noodles are almost pure carbohydrate. A one-cup serving of cooked cellophane noodles (about 190 grams) contains roughly 160 calories, 39 grams of carbohydrates, and virtually zero protein, fat, or sugar. They’re essentially starch and water in noodle form, so they won’t contribute meaningful vitamins or minerals to a meal on their own.
Where they do stand out is glycemic impact. Mung bean glass noodles have a glycemic index of around 28, which is remarkably low. For comparison, white bread scores 100 on the same scale, and even whole wheat pasta typically lands in the 40s. This means glass noodles cause a much slower, smaller rise in blood sugar after eating, which can matter if you’re managing blood sugar levels.
Part of the reason for that low glycemic score is resistant starch, a type of starch that behaves more like fiber in your body. Cooked glass noodles contain roughly 11 to 17 percent resistant starch, and that number actually increases if you cool the noodles after cooking (like in a cold noodle salad). Resistant starch passes through the small intestine undigested and feeds beneficial gut bacteria in the colon, functioning as a prebiotic.
How They Differ From Other Clear Noodles
Not every translucent noodle is a glass noodle. Shirataki noodles, popular in Japanese cuisine and marketed as a low-calorie alternative, are made from konjac yam flour mixed with water. They’re almost entirely fiber with close to zero calories or carbohydrates, which makes them a completely different food from starch-based glass noodles despite looking similar in the package.
Rice vermicelli can also appear somewhat translucent, but it’s made from rice flour and has a different chew. Glass noodles become slippery and springy when cooked, while rice noodles stay softer and more delicate. If the ingredient list says “mung bean starch,” “sweet potato starch,” or “pea starch,” you’re looking at true glass noodles.
Additives to Be Aware Of
The ingredient list on a quality package of glass noodles should be short: starch and water. However, some manufacturers, particularly smaller or traditional producers, add alum (an aluminum compound) to strengthen the noodles and keep them from breaking apart during cooking. A study analyzing noodle products from Chinese markets found detectable aluminum in three out of four vermicelli samples tested, at levels between 0.04 and 0.14 mg per gram.
If this concerns you, check the ingredient label for alum or aluminum-related compounds, and opt for brands that list only starch and water. Products sold in the U.S., EU, and other regulated markets are more likely to skip these additives.
How to Cook Them
Preparation depends on which type you have. Mung bean glass noodles are the easiest: soak them in room-temperature or warm water for 10 to 15 minutes until they soften, then add them directly to stir-fries, soups, or spring rolls. If you’re serving them on their own, a quick one to two minute boil after soaking is enough.
Sweet potato starch noodles need more patience. They require soaking for at least two hours before cooking to become pliable enough to work with. Skipping this step leaves you with tough, unevenly cooked noodles. After soaking, they go into boiling broth or water until fully tender, which takes a few more minutes than the mung bean variety. Both types absorb the flavors of whatever sauce or broth they’re cooked in, which is a large part of their appeal in dishes like hot pot, japchae, and glass noodle salads.