The rice vinegar produced using this traditional method has a deep brown color, with a clear, rich, and tangy flavor. For every 50 kilograms of glutinous rice used, you can produce approximately 225 kilograms of rice vinegar. This vinegar is not only suitable for pickling sauerkraut but can also be mixed into pig feed, offering excellent economic returns.
**Raw Material Formula:**
To begin, you'll need 50 kg of glutinous rice and 2 kg of distiller's yeast (such as sweet sake or liquor yeast in powdered form). The yeast plays a crucial role in the fermentation process, so it's important to use high-quality, active yeast.
**Operating Technology:**
1. **Soaking:** Soak the glutinous rice in water, ensuring the water level is about 20 cm above the rice layer. In colder seasons (winter and spring) when temperatures are below 15°C, soak the rice for 12–16 hours. During warmer months (summer and autumn), when temperatures exceed 25°C, reduce soaking time to 8–10 hours. In summer, change the water 1–2 times to prevent the rice from becoming too acidic.
2. **Steaming the Rice:** After soaking, rinse the rice thoroughly with clean water, drain slightly, and place it in a steamer. Steam for 10 minutes, then sprinkle a small amount of water over the rice and steam for another 10 minutes. The rice should become soft, sticky, and visually glossy, making it ideal for fermentation.
3. **Mixing with Yeast:** Once the rice has cooled down to around 25–30°C, spread it on a bamboo mat and mix it evenly with the distiller’s yeast. Make sure the mixture is well combined to ensure uniform fermentation.
4. **Fermentation:** Place the mixed rice in a fermentation vessel. In cold weather, cover the vessel with blankets or straw mats to maintain warmth. In warmer seasons, keep the area well-ventilated. The optimal temperature for fermentation is between 25–30°C. After 24 hours, a slight alcoholic aroma will develop. By the 36th hour, the liquid will start to ooze out, appearing golden, sweet, and sour, which indicates that the fermentation is proceeding normally.
5. **Vinegar Production:** Continue fermenting for an additional 3–4 days to allow for full saccharification and alcohol production. When the liquid begins to turn slightly acidic, add 200–225 liters of clean water per 50 kg of cooked rice. This dilution helps lower the alcohol content, making it easier for acetic acid bacteria to thrive and convert the alcohol into vinegar naturally.
6. **Final Product:** After the vinegarization process, the final product will take 20–30 days in summer and autumn, and 40–50 days in winter and spring. At this point, a thin layer of acetic acid vinegar forms on top, with a strong, pungent sour smell. The upper layer appears bright orange, while the middle and lower layers are slightly cloudy. Combining these layers results in white vinegar. To enhance flavor, spices, sugar, and colorings may be added before filtering. For the best quality, old vinegar should be aged for 1–2 years.
Frozen Fish,Frozen Bonito Tuna,Frozen Mackerel Fish,Fresh Frozen Mackerel Fish
ZHEJIANG RETRONX FOODSTUFF INDUSTRY CO.,LTD , https://www.retronxfoods.com