Tips for homemade shrimp oil

Shrimp oil is a kind of compound water-soluble shrimp paste extract with amino acids and shrimp flavor as the main components. It is made by hydrolyzing protein, sugar and fat in shrimp by various enzymes at a certain temperature. There are many enzymes in shrimp, including trypsin, chymotrypsin, carboxypeptidase and caseinase, which can hydrolyze peptide bonds. Amylase and chitinase which can hydrolyze polysaccharides; Lipase that can hydrolyze triglycerides into glycerol and fatty acids. [2]

Traditional handicrafts

Raw material cleaning

Shrimp oil processing season is one month before Qingming every year. During processing, all kinds of small miscellaneous fish with low economic value are washed to remove sediment and impurities. Shrimp needs to be washed in seawater with shrimp nets, and then the nets are pulled after removing sediment, and then poured into baskets and transported back for processing. [3]

Pickling in tank

The container for brewing shrimp oil adopts a pottery jar with a wide mouth, a big belly and a small bottom. Cylinder discharge

shrimp

shrimp

An open field where fermentation is carried out in the sun. The cylindrical surface is made of bamboo and lined with bamboo leaves or plastic film. Pour the cleaned raw materials into the cylinder, and the capacity of each cylinder is generally 150~200 kg, accounting for about 60% of the cylinder volume. After two days of sun exposure and night dew, stir it once every morning and evening. After 3~5 days, when there is red foam on the cylinder surface, add salt and stir. Every morning and evening, add 1 ~2 kg of salt when stirring, depending on the degree of sprinkling on the cylinder surface. After 15 days of pickling in the tank. When shrimps don't float or rarely float in the tank, the salt consumption can be reduced by 5% by continuing to stir once every morning and evening. After a month, stir it in the morning and add a little salt. Until the specified amount of salt is used up. The amount of salt used in the whole curing process is 16~20% of the raw material. [3]

Exposure fermentation

The brewing process of shrimp oil mainly depends on sun exposure and stirring in the morning and evening. After sun exposure and night dew, the longer the stirring time, the more times, the stronger the sun exposure, the less the fishy smell and the better the quality. In rainy days, the salt pot needs to be covered. After the above process, the tank becomes thick black sauce, and when a layer of clear oil floats on it, the fermentation is over. [3]

Refining and cooking

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Shrimp oil fermentation

Shrimp oil fermentation

The dried fermented shrimp paste can be refined from dog days to early autumn. Skim off the floating oil on the surface of the cylinder with a spoon, and then dissolve it with 5~6% salt into cold saline solution and flush it into the cylinder. The dosage is the amount of raw materials minus the first oil slick scooped up. After adding salt water, stir for 3 ~ 4 times to promote the separation of shrimp oil and shrimp residue in the tank. Then put the bamboo basket into the tank, filter the shrimp oil into the basket, and gradually scoop it up with a spoon until the shrimp oil in the tank is completely scooped up. Then the shrimp oil scooped out before and after is mixed and stirred to obtain raw shrimp oil.

Boil the raw shrimp oil in a pot, skim the floating foam in the pot, and precipitate to obtain the finished shrimp oil. At this time, the spoon barrel will continue to be exposed to the open air, and an arc-shaped barrel cover will be added on it for ventilation. The concentration of the finished product is 20 degrees Bomei. When it is not up to standard, add salt in moderation when cooking; If it exceeds the concentration, it can be diluted with boiling water. [3]

Modern craft

Purification and sterilization

Remove impurities after shrimp fishing and rinse with clean fresh water. The sterilization time should be fast, otherwise the bactericide will easily enter the shrimp to kill the enzymes in the body and affect the fermentation. [2]

Salt mixing and heat preservation

In order to speed up the fermentation, the concentration of mixed salt is 10- 15%, especially edible salt. Heat preservation can be carried out in a special fermentor. [2]

Salt water distribution and pressure filtration

The purpose of brine preparation is to increase the concentration of salt to meet the national standards. Besides,

Fermentation tank

Fermentation tank

Zanthoxylum bungeanum, aniseed and tea can be added appropriately to improve the flavor. The purpose of pressure filtration is to separate shrimp oil and shrimp paste. This operation can be carried out in filter press or vacuum filter to make the filtrate as clear as possible, otherwise it will reduce the output of shrimp paste and bring inconvenience to the disinfection process of shrimp oil. [2]

Sterilization and bottling

Because some water-soluble protein and peptides will attract each other and flocculate and precipitate after standing for a long time. In order to prevent shrimp oil from settling, a proper amount of stabilizer should be added. Boil shrimp oil for a few minutes, then bottle it, filter out precipitated and suspended impurities while it is hot, and bottle it while it is hot.