1. Prepare 50 grams of homemade potato starch and add 30 grams of cold water.
2. Use chopsticks to mix the starch with the cold water to form a thin soupy starchy water.
3. Pour 100 grams of cold water into a pot and boil over high heat until the water boils.
4. Immediately add the boiling hot water to the starchy water.
5. Pour boiling water while stirring quickly in one direction with a rolling pin.
6. Until the thin soupy starch water stirred into a clear paste, slightly tough, lift the rolling pin can see the paste starch can be pulled wire.
7. Add 250 grams of dry potato starch to the blended starch paste while it is still hot.
8. Prepare an egg and strain out the egg white.
9. Pour the egg white into the dry starch.
10. Add 1/4 teaspoon of salt.
11. With your hands, scrunch together the starch paste, dry starch, egg whites and salt.
12. Form a dough with a smooth surface.
13. Prepare the tool for making potato vermicelli, which is a must-have tool for making noodles at home in Shanxi and can be bought online.
14. Open the lid on top of the tool.
15.Grab a handful of potato dough and stuff it into the hole in the center.
16.Put the lid on and tighten it.
17.Holding the handle of the tool in your left hand and the handgrip in your right, rotate the handle toward the right.
18.As the handle rotates, the potato vermicelli is squeezed out.
19. Put enough cold water in the pot and boil it over high heat.
20.As the water in the pot boils, move the tool over the pot and let the extruded potato vermicelli flow into the pot while squeezing.
21.Cook until the potato vermicelli in the pot floats up to the surface of the water.
22. Drain the spaghetti with a slotted spoon and place immediately in a bowl of cool water, repeating several times to cool the spaghetti.
23. The cooled spaghetti can be served cold or in stews.
24. If you don't eat it immediately, you can put the potato vermicelli in a plastic bag and store it in the refrigerator.