Pour the fresh potatoes into the tank, add clean water, and wash them manually. After washing, take them out and drain the remaining water.
After draining, the fresh potatoes are crushed into pieces with a crusher. The size of the potatoes is less than 2 cm, which is good for grinding.
Put the fresh potato pieces into a stone mill or an emery mill, add water or a small slurry, and grind them into potato paste. The ratio of fresh potato weight to water addition is 1:3-3.5.
Commonly known as Da Luo. Pour the potato paste into a 60-mesh sieve for sieving. Add water to rinse during the sieving process, and also use Physalis to rinse.
Put the filtered starch milk into a large tank, and then add acid pulp and water in proportion to adjust the acidity and concentration of the starch milk. The acidity and concentration of starch milk are closely related to the precipitation of starch and protein. If the lactic acid of starch is too high, starch and protein will precipitate at the same time, making the separation of starch unclear. If the acidity is too low, the precipitation of protein and starch will not be good, and they will be emulsions, which cannot be separated. According to production experience, the optimum pH value of physalis is 3.6-4.0. The concentration of starch milk in the large tank is 3.5-4.0 degrees Baume, the amount of acid syrup added is 2% of the starch milk, and the pH value of starch milk after adding acid slurry is 5.6. If the temperature is high and the fermentation is fast, the amount of physalis can be reduced as appropriate.
After mixing the slurry, let it stand for about 20 to 30 minutes to complete the precipitation, and then skim the vat. Take out the upper layer of clear swill and the mixture of protein, fiber and a small amount of starch (commonly known as hair powder), and the bottom layer is starch. The wool powder must be scooped out and filtered, the starch is recovered, and put into a large tank, and the filter residue can be used as feed.
Add water to the bottom starch after skimming and mix to make starch milk, so that the starch can be re-precipitated. During the precipitation process, it plays a role in the fermentation of acid slurry, so it is called sitting cylinder. The temperature and time should be controlled when sitting in the cylinder. The sitting cylinder temperature is about 20°C. It must be kept warm in cold weather or hot water can be used when adding water to mix. Fermentation in tanks must be thoroughly developed, and stirring should be done properly during the fermentation process to promote the completion of fermentation. Generally, the sitting time is 24 hours, and the time can be shortened accordingly in hot weather. After fermentation, starch precipitates.
The Physalis produced by sitting in the vat is called Erhe pulp, which is the Physalis mainly used in the Physalis method. Normal fermented physalis has a clear fragrance. The paste color is as white as milk. If the physalis is under-fermented or over-fermented, the color and fragrance are poor, and the effect is not good when used for pulping. Skimming means to skim off the upper layer of soy pulp for mixing.
The starch after skimming is sieved with a 120-mesh fine sieve. The sieve is fine slag, which can be used as feed. The under-sieve is starch, which is transferred to a small tank.
After the starch is transferred to the small tank, add water to rinse the starch and leave it for about 24 hours to prevent fermentation.
After the starch is precipitated in the small tank, the upper liquid is a small slurry, which can be used in conjunction with the physalis, or as water for grinding. After skimming off the small pulp, a layer of off-white oil powder remains on the surface of the starch, which is impure starch containing protein. The oil powder can be washed away from the starch surface with water, and the washing liquid can be used as a nutrient material for cultivating physalis. The bottom starch is taken out with a shovel. There may be fine sand adhering to the bottom of the starch, which should be brushed off.
Scoop out the starch and put it into the square cloth. The four corners of the square cloth are fastened with ropes. After hanging up, the water in the starch will drip and drain. In order to shorten the hanging time, the wrapping cloth can be properly vibrated to speed up the water leakage.
The wet starch taken out from the cloth contains about 40-45% water. Can also be made into finished products. In order to facilitate storage and transportation, it must be cleaned. Generally, it is dried in the sun or sent to the drying room for drying.