Brine Processing Method and Technical Key Points for Oyster Mushrooms

Oyster mushroom, also known as abalone mushroom, is an edible fungus that can be eaten fresh or processed into canned goods for export, and is extremely rich in nutrients. Brine processing of oyster mushrooms is simple to operate, easy to transport, and offers relatively high economic returns.

Grade standards for oyster mushrooms (divided into 2 grades in total). Grade 1 mushrooms: grayish-white in color, 3-12 cm in diameter, without stems; the few with stems must not exceed 1 cm. The tissue is tender, the shape is complete, the edge of the cap has no severe shrinkage or cracks, no mud, sand or other impurities, no pests or diseases, no shrinkage or deterioration, and no off-odor.

Grade 2 mushrooms: grayish-white or grayish-brown, 3-12 cm in diameter, with stems but not exceeding 1 cm. The tissue is tender, the shape is basically complete, the edge of the cap allows cracks not exceeding 1/4 of the whole mushroom, no mud, sand or other impurities, no pests or diseases, no shrinkage or deterioration, no off-odor, and must not be soaked in water.

Finished product specifications. 1. Color: light gray, with a small amount of grayish-brown allowed.

2. Tissue form: whole mushrooms and fan-shaped pieces must be packed separately.

(1) Whole mushrooms: oyster mushrooms with a transverse diameter of 3-10 cm.

(2) Fan-shaped pieces: the shape measured by chord length must be no less than 2 cm.

3. Odor: should have the aroma of fresh oyster mushrooms after pickling, with no off-odor.

4. Impurities: fragments of glass, metal shavings and other animal feces and impurities are absolutely not allowed.

5. Sodium chloride content: above 19%; crystallized salt is not allowed in the finished product.

Process flow: acceptance inspection -> rinsing -> pre-boiling -> draining and rinsing -> sorting -> pickling -> inspection -> packaging

Production method. 1. Acceptance inspection: inspect according to the grading standards and place them separately.

2. Rinsing: place qualified oyster mushrooms in a large basin and soak them in clean water for 25 minutes, then wash one by one the mud, sand and other impurities in the gills on the surface of the caps, and at the same time grade them again according to quality requirements.

3. Pre-boiling: the ratio of cold water to mushrooms is 1:1, pre-boiling time is 8-10 minutes, add 0.77% citric acid to the pre-boiling water in proportion, and after pre-boiling remove promptly and rinse with cold water.

4. Pickling: weigh 100 kg of oyster mushrooms and 25 kg of salt, pour the oyster mushrooms onto a stainless steel board (or into a basin), mix evenly while adding salt, then pour into a jar for pickling. The pickling container should be washed clean, and a small amount of salt should be added to the bottom of the jar; after pickling, add a small amount of salt on the surface of the jar as well.

On the second day after pickling, turn the contents of the jar so that the oyster mushrooms on top are turned into the middle layer. When turning, if the brine has not covered the mushroom surface, add brine with a concentration of 25% that has been boiled and cooled, so that the brine covers the mushroom surface.

5. Inspection: during the pickling process of oyster mushrooms, check their quality frequently. If abnormalities are found, handle them as appropriate. At normal room temperature (15°C), conduct a salt content inspection of the finished product on the seventh day. There are two methods.

(1) Baume inspection method: use a Baume meter of 0-30°Bé. Before inspection, calibrate 0° with clean water (water temperature 20°C), then take 500 ml of brine from the middle of the jar and from a depth of 20-30 cm at the front and back, pour it into a basin, take 200 ml from it and pour it into a 200 ml cylinder, and measure with the Baume meter. At this time the Baume degree should be between 20-22 Bé; otherwise, add a small amount of salt and continue pickling to reach the standard salt content. This is very important for preventing spoilage.

(2) Silver nitrate method: from the middle of each jar (tank) and from a depth of 20-30 cm at the front and back, take 200 g of mushroom samples from each location, mix them, take 200 g, cut and mix thoroughly with a knife, then take 10 g. The determination method follows the national standard.

6. Packaging: (1) Selection: remove impurities and oyster mushrooms that have turned black.

(2) Packaging: each box holds one bag, with an additional outer bag, filled with 25 kg of oyster mushrooms, plus 0.5 kg of brine (to reduce bruising during transport and maintain color), then remove the air from the bag. Seal with a heat sealer. Add one sheet of moisture-proof paper to the bottom and top of the box; seal the bottom and lid with adhesive and sealing tape along the box seams, and tie two strands of paper tape or plastic tape around the outside of the box.

Other packaging such as plastic buckets may also be used, filled according to specification requirements, taking care to add an appropriate amount of brine.

Precautions. 1. After oyster mushrooms have been pickled for 15 days, if the salt content is insufficient, spoilage will occur: the mushroom color turns yellow and shiny, and the aroma disappears. Yellowing of the mushrooms is a sign of spoilage; rework them immediately. If the odor is not severe, they can be removed again and pickled with an additional 10-15% salt; those with a severe off-odor should be discarded.

2. Oyster mushroom processing should be carried out in an acidic environment; contact with alkali will cause blackening and rotting.

3. Do not use iron utensils as processing tools; iron will blacken the product.

4. Pickled products must not come into contact with oils; oils will shorten the shelf life of the product.

Quota for processing oyster mushrooms (1000 kg of finished product). 1. Salt 300 kg, citric acid 3 kg, paper tape 90 m/1.5 kg, plastic bags 90 pieces/8.1 kg, cardboard boxes 45 pieces, moisture-proof paper 90 sheets/6 kg

2. Plastic bag specifications: polyethylene plastic film

Thickness 0.07 mm, length 90 cm, width 80 cm, bag opening width 50 cm, shoulder height 60 cm