How to make lemonade in milk tea shop

The practice of lemonade in tea shop is as follows:

Tools/materials: three slices of lemon, 20g of rock sugar and some ice cubes.

1, wash the lemon, rub it with salt, wash it, slice it, and put it in a shake glass.

2. Add rock sugar to the cup.

3, add cold boiled water, do not use hot water.

4. Fasten the lid and shake it a few times.

5, put the cup in the refrigerator, cold storage for an hour or two, until the crystal sugar completely melts, shake up and down evenly.

6. Take a glass, put it in ice, take the shake cup out of the refrigerator, shake it well and pour it into the ice.

7. Lemonade is ready.