1. Freezing preservation method: firstly, blanch the cleaned Ulmus pumila in boiling water, quickly take it out and cool it in cold water, then take it out and put it in a sunny and well-ventilated place, dry the raw water on the surface of Ulmus pumila, then pack it in plastic bags, tie the bags tightly, and then put it in the refrigerator for freezing preservation. If you feel that the blanching step is a bit troublesome, you can completely omit the blanching step and directly dry the raw water on the surface of elm for freezing preservation. The lazy way is not to wash, just spread the elm out and air it a little, as long as there is no raw water on the surface, it can be bagged and frozen.

2. Sun-drying preservation method: blanch the cleaned Ulmus pumila in boiling water, take it out and drain it, spread it in a sunny and well-ventilated place to dry it thoroughly, put it in a plastic bag and tie the bag tightly, then store it in a ventilated and dry place indoors. Soak in boiling water before eating and rinse with clear water several times.

3. Cold storage method. Don't wash the picked elms, put them in a pot, sprinkle a proper amount of corn flour on the elms, gently stir them evenly, then put them in a fresh-keeping bag, tie the bag tightly and put them in the refrigerator for refrigeration. This method has a good preservation effect, but it can only be preserved for about seven days at most, which is suitable for short-term preservation of fresh elms. The reason why corn flour is used in the cold storage method is that it has large particles, is not easy to adhere, can absorb excess water well, and can retain the water of elm trees.

4. Sauce-making and fresh-keeping method: the old elm can be made into elm sauce for fresh-keeping, that is, the old elm is washed and dried, then the dried elm is ground into powder, and fermented for a period of time after adding seasoning to make the elm sauce for fresh-keeping. Elm sauce is basically the same as making noodle sauce, but it is very delicious.