Sufu (fermented bean curd)

What sufu is

Sufu, also called furu, is a Chinese fermented soy food made from tofu. The literature describes a creamy, spreadable product. It starts with tofu or pehtze, the tofu that has been grown over with mould, then salting and a period of ripening. Red, white, grey and other types are linked to the process or to the dressing the pieces are packed in.

It is a condiment, eaten in small amounts with breakfast rice or steamed bread. A review of the food cites Wei Dynasty written records from 220 to 265 CE. Those statements concern the food in general and do not date or place any single recipe.

Colour labels name the dressing, not the organism. A paper on huase sufu separates red sufu, made with a red colorant, from white sufu without one, and shows that neither label identifies the surface culture.

Three creator methods

The method steps above come from three home-cooking videos. They are different batches, not one recipe in three versions.

The first video cuts tofu, covers it with gauze, waits several days while growth appears on the exposed surface, and then moves it into cooled salt water. The starter, the salt concentration and the amount of tofu are not stated.

The second dusts three blocks of old tofu with 6 g of a packet sold as tofu-ru starter, holds them in an unpowered oven or steamer, then coats them with chilli seasoning and liquor and packs them with oil. The packet's brand and contents are not identified. Soy sauce that appears later in the video belongs to a separate duck dish.

The third uses purchased salted, sun-dried tofu layered with pineapple, sugar, rice wine and rice koji. The creator sets it apart from two earlier pineapple batches, one with fermented black beans (douchi) and one with pineapple alone. At one point the captions mark an 80-piece statement as an oral slip, then show the tofu cut in half and the creator saying all 80 pieces are complete, so the count could refer to the bought pieces or to the halves. Piece size and total mass are not stated.

Culture and growth

The sufu literature names Actinomucor, Mucor and Rhizopus among the fungi used for some mould-fermented types. That does not show which organism grew in the first video or what the packet in the second contained, and pale or grey growth cannot establish a species.

The pineapple version starts from bought tofu that has been salted and sun-dried, without the mould-grown stage, so whether it ripens like mould-fermented sufu is not established.

Names and neighbouring foods

Sufu, stinky tofu, plain marinated tofu and fermented beans are not automatic synonyms. One article classes Qing sufu as stinky tofu, while separate research examines the bacterial brine used for stinky tofu. Terminology varies, so these are comparison foods, not aliases. Tofu packed with seasoning but showing no sign of fermentation is not sufu. Douchi appears here only as a flavour the pineapple creator tried in an earlier batch.

Place, use and home feasibility

The literature gives Chinese food context, not a location for any creator or batch. The Chinese caption codes (zh-CN, zh-HK, zh-TW) do not show where the videos were made. The pineapple creator mentions rice porridge, steamed buns, noodles and noodle dumplings as ways to eat it.

The videos name gauze, jars, a tray, a sieve, an unpowered oven or steamer, a bowl and utensils, but leave out the quantities and controlled conditions an executable home method needs. No chamber dimensions are supported.

What the evidence does not settle

No qualified review validates these batches. The first two videos do not identify the surface culture or give measured process controls. Visible growth or a reported wait is not a safety test, and the starter and storage statements stay creator claims, not recommendations. The captions were read as archived text, without the audio or video, and can contain translation or recognition errors.