The Production Process of Flavored Dried Tofu

Soybean raw material → Washing & sorting → Soaking → Grinding into pulp → Separating pulp from residue → High-temperature boiling of the pulp → Cooling → Adding coagulant → Pressing to form tofu

　　Soybeans are rich in nutritious proteins, healthy fats, and trace nutrients—including microorganisms, minerals, and plant-based compounds like phytosterols and isoflavones. In China, soy-based foods have been consumed for thousands of years.

　　1. The Production Process of Dried Tofu Puffs

　　Soybean raw material → Washing & sorting → Soaking → Grinding into pulp → Separating pulp from residue → High-temperature cooking of the pulp → Cooling → Adding coagulant → Pressing

　　1. Raw material selection, washing, and soaking: Choose high-protein soybeans that are free from impurities, insects, or mold—ensuring they’re of superior quality. Rinse the beans thoroughly with clean water before transferring them to a soaking tank, where they’ll be covered with fresh water. The soaking time varies depending on the ambient temperature: typically, soak for 24 hours at 5°C, 18 hours at 10°C, and just 8 hours at 27°C. On average, soybeans absorb about 1.2 times their own weight in water.

　　2. Grinding the soybeans. Grind the soybeans finely, dissolving the soy protein into water, while carefully controlling the amount of water added to maintain the desired concentration of the soy milk. The soy milk should be adjusted to a concentration of 13° Baumé.

　　3. Slurry separation: Use a pump to draw the soybean slurry into the slurry separator, where centrifugal force is applied to spin out the soy milk. A screen mesh with 80–100 mesh is ideal for the separator.

　　4. High-temperature boiling and cooling of the slurry. Add a defoaming agent to the slurry at 0.8%–1% based on the weight of the soybeans. Using monoglycerides as the defoaming agent not only eliminates foam but also enhances the quality of the soybean products. Heat the slurry to 75°C and maintain this temperature for 5 minutes, then raise the temperature to 95°C and hold it for another 5 minutes, before finally cooling the mixture down to below 30°C.

　　5. Add a coagulant: Glucono-delta-lactone is the preferred choice.

　　6. Pretentious and Overbearing

　　2. Key Points for Preserving Flavored Dried Tofu During Post-Production

　　Dried tofu puffs (available in homemade and outsourced versions)

　　1. After making it yourself, immediately proceed with braising (which reduces secondary contamination).

　　2. For outsourced products, secondary contamination may occur during transportation and other stages. Therefore, it's best to soak the dried tofu blanks in 150 ppm chlorine dioxide or food-grade hydrogen peroxide for 20 minutes as a pre-treatment step to eliminate bacteria.

　　3. Since the brine is used in a recycling system, it must be brought to a boil both before and after each use, and residual sediment should be regularly removed using a filter cloth.

　　Soy products are neutral foods, and since most preservatives used are acidic—resulting in poor effectiveness—they, combined with the high protein content and rich nutritional value of soy products, actually promote bacterial growth.

　　Preservatives permitted for use in soy products under GB2760:

　　Calcium propionate ≤ 2.5‰, potassium sorbate ≤ 1‰, sodium diacetate ≤ 1‰