How to make dried longan

The processing and roasting technology of dried longan is relatively traditional and has formed a relatively mature technology so far. There are two roasting methods: sun drying and baking. Sun-drying is relatively simple and suitable for small-scale production at home; baking is done manually using a baking stove, which is currently used in large-scale production of dried longan. Modern baking methods include mobile drying production lines and fixed drying production lines.

(1) Baking method

Process flow: raw material selection→cutting→soaking in water→shaking sand and rubbing skin→baking→cutting stems→hanging yellow→rebaking→grading→packaging.

1. Selection and processing of raw materials

(1) Selecting fruits for baking and drying longan varieties requires large fruits, thick flesh, slightly thick or moderately thick shells, and high pulp content. High in sugar. Longan fruits made from Wulongling, Youtanben, Chike, Shuangmu, Chuliang, Wuyuan, etc. need to be fully mature and picked in time.

(2) Cutting the stems: After the fruits are delivered to the processing plant, use small flat-mouth scissors to cut off the fruit stems one by one, starting from the base of the fruit stems.

(3) Put the fruits after being soaked in water and cut into bamboo baskets and soaked in water for 5-10 minutes. Wash off the dirt on the fruit surface and make the shell soft. Then lift it up to drain the water in preparation for shaking. .

2. Shake with sand and rub the skin

Pour the water-soaked longan fruit into a special shaker and add fine sand to shake and rub it to remove the rough surface on the outside of the fruit shell. The longan that has been shaken with sand is easy to dry and is more uniform. The surface of the finished product is smooth and the color is beautiful.

Specific method: Hang the swinging cage, with one person standing on each side, rocking back and forth. Each cage holds 35-40 kilograms of fruit, add 0.5 kilograms of river sand, and shake rapidly back and forth to make the fruits continuously roll in the cage, rub each other, and numb the surface of the fruit shell. Generally, it takes 300-400 times to shake the fruit back and forth. It's ready when it turns brown and dries.

After shaking the sand, pour out the longan fruit pellets and wash away the sand and powder adhered to the surface of the fruit shell with clean water.

3. Baking

Baking is an important step in the process of processing dried longan. Baking stoves are mostly made of bricks or adobe, with a length of 2.1 meters from front to back, a width of 2.2 meters from left to right, a height of about 1 meter at the front, and a height of about 1.2 meters at the back. The entire stove surface is tilted forward, which facilitates operation and uniform firepower when baking fruits. There is a stove door with a height and width of 50 cm each on the front wall of the stove. The door of the wood-burning stove is in the shape of an isosceles triangle, and the door of the coal-burning stove is in the shape of a square. 5-6 baking beams are erected 25 cm away from the top of the stove wall, and bamboo curtains are laid on them. The shed surface is tilted forward. The peeled longan fruit is spread out on the shed, about 20 centimeters thick. One baking stove can bake 300-400 kilograms of fruit at a time; if 2-4 stoves are connected side by side to form a conjoined baking stove, 800-1,200 kilograms of fruit can be baked at a time.

Baking is carried out in two steps, namely initial baking and re-baking. The key to technology lies in mastering the size and uniformity of firepower, and rebaking must be timely and even. The initial baking takes about 24 hours, and the temperature is controlled at 65-700C, so that the bottom longan shell is quickly heated and hardened to avoid being dented by pressure. After baking for 6 hours, the first flip-baking is carried out. The fruits are taken out in the upper, middle and lower layers respectively and placed in bamboo baskets. Then the upper and lower layers are swapped, and the middle layer remains unchanged. Then they are spread on the shed surface and continue drying. After baking for 6 hours, bake for the second time. At this time, the middle layer will be used as the bottom layer, the upper layer will be used as the middle layer, and the lower layer will be used as the upper layer. After that, the third and fourth roasting will be done every 4 hours. The third time is to swap the upper and lower layers, and the fourth time is to swap the front and back in two sections. If it is only roasted 3 times, it should be roasted once every 6 hours, and the third and fourth roasting operations should be combined, that is, the upper and lower layers should be swapped on one side, and the front and rear sections should be swapped on the other. At this time, the excellent finished product after initial baking has a hard outer shell, a yellowish-brown or russet flesh with an oily sheen, and fine wrinkles. The outer skin of the core is easy to fall off, and the kernel is pale white.

Put the initially roasted dried longan in a bamboo basket, pick out the broken shell dried fruits, and turn the basket once a day. After 4-5 days, it can be re-baked. The baking temperature is controlled at about 600C, the time is 6 hours, and the baking time is once every 2 hours. Bake until the fruit base falls off when gently pushed with your fingers. At this time, the fruit pulp will appear fine wrinkles, dark brown, and the surface is dry. If you bite the core with your teeth, it will easily crack and become brittle, and the cross section will be grassy gray.

The drying rate of longan varies depending on the variety, generally 33-37.

4. Cut the stems. After baking, use small scissors to cut the dried longan fruit stems flat.

5. Hanging yellow

The process of hanging yellow depends on needs. For export, first, second and dried longan, in order to improve the appearance of the fruit, it is necessary to dye the fruit surface with yellow turmeric powder, which can not only improve the appearance of the product, but also have a certain effect on preventing insects. The medicine for hanging yellow is composed of 70% yellow powder and 30% white clay. When yellowing, put 12-14 kg of dried longan into a shaking cage, wet it with a little water, and shake it while watering. After the fruit surface is evenly moist, add 300-400 grams of turmeric powder and shake it back and forth. 300-400 times to make the fruit surface evenly colored. Then spread the dried fruits on the baking stove for drying at a temperature of 40-500C and a time of 1-2 hours, based on drying.

(2) Sun-drying method

In sunny weather, put the fruits in ears on a drying tray and expose them to the sun for 1 day, turning them once during the period, then cut off the single fruits and dry them until At 1 o'clock in the afternoon the next day, stack the drying trays, cover them with sacks or straw bags, let them regain moisture, store them for one to several days, and then spread them out to expose them to the sun. At noon, stack them up and regain moisture, 1-2 times in a row, and gradually dry them until the peel is damaged. That's broken.

Sun-drying can also be combined with baking method, that is, sun-drying and baking method. Spread the mature fruits on a drying tray to dry for 1-2 days, turn them once a day. After the peels become soft, place them on the drying bed and bake them at 60-650C for 12 hours. After turning them, remove them and let them sit for 1-2 days to regain moisture. , and then bake for 2-4 hours, until the peel will crack with one blow.