1 picking material
Choose tomatoes which has thick flesh and less juice, and it should not over ripe. Afterwards, remove those fruits which is insufficiently ripe, and those which has been suffered by diseases and insect pests, or has been damaged should be remove out as well.
After washing the tomatoes, you should pour the washed tomato fruit in boiling water for about 1 minute, and then cool it down immediately. Afterwards, peeling off the skin of the tomato.
3 squeezing juice
Dig and slit the stem at the tomato stalk, and squeeze out the juice lightly.
The fruit blank is mixed with 0.30% calcium chloride solution and should be soaked for 2 hours.
Wash the hardened fruit embryo with water, remove the fruit embryo, and drain away the water.
Drain the tomato embryo, soak it in 30% sugar solution for 24 hours, add 0.30% citric acid to the sugar solution for macerating.
Pour the soaked tomatoes together with the dipping liquid into the jacketed pot, slowly heat up to boiling, after about half an hour, put the fruit juice together with the boiled sugar liquid and soak for 12-24 hours. You should repeat the aforesaid soaking process repeatedly for 2-3 times, and should increase the concentration of sugar solution each time. When the concentration of the boiled sugar solution reaches 65%, stop the fire, and pour it into the pot for 8-10 hours. Afterwards, you should drain the sugar solution.