Learn the basics of sweet potato starch and a super-easy way of making it at home. It can be used in many traditional Chinese dishes like Sichuan deep-fried pork or even used to make sweet potato noodles.
What's sweet potato starch or sweet potato flour?
Sweet potato starch (红薯粉 in Chinese) is a very popular starch used in Sichuan cuisine. Like tapioca starch, sweet potato starch can also help to create a lovely chewy texture when cooked with water. But the Chinese name should be translated as sweet potato flour. But it actually is a starch flour.
It can be made at home with a simple method
I get lots of feedback saying it is quite hard to get sweet potato starch. The good news is it is quite easy to produce sweet potato starch at home. If you don't need to store it, it can be quite easy. Once sweet potato starch is made, we can further make lots of yummy dishes using this simple ingredient. If you replace sweet potato with regular potatoes, you can make potato starch too.
Sweet potato starch features
As the strongest straight-chain amylose, sweet potato starch is quite magic in usage. Compared with other starch, sweet potato starch is more stable after cooking (hard to dissolve in water), we usually used it as a coating for lots of Sichuan dishes like water-boiled dishes including water-boiled beef, water-boiled fish and water-boiled pork. Or in other cases, they are used in taro balls. But it is not a good option for thickening since the stickiness is quite strong and hard to control. My father usually makes a large batch of sweet potato starch in winter just after the sweet potatoes are harvested.
How to use sweet Potato Starch
- Sweet potato starch can be used as marinating ingredients in most of the common Chinese stir fry recipes like beef and Chinese broccoli, pork, and mushroom stir fry.
- It is the best type of starch for all Sichuan-style water-boiled dishes, working also as a protection for meats. Example: Sichuan boiled pork.
- When used in desserts, sweet potato starch usually helps to create a chewy texture, like Taiwanese taro balls.
- In the Sichuan area, we love to use sweet potato starch in a deep-frying batter and make delicious Sichuan-style crispy pork (酥肉).
- Like other starches, sweet potato starch can be also used to make jelly.
- Sweet potato starch can be mixed with an appropriate ratio of water and further make noodles. Sweet potato starch noodle is the key ingredient for Sichuan style Hot and Sour Noodles (酸辣粉).
- Steamed noodles can be also made with a thin sweet potato starch batter. Which is further cut into large pieces and usually cooked in soups and hot pots. In Sichuan, we call this "火锅粉".
How to make sweet potato flour at home
Note firstly: I tested with 1500g sweet potatoes (skin removed) and get around 180g pure sweet potato starch this time. The actual ratio is between 10% to 20% depending on the different types of sweet potatoes.
Remove the skin care and make sure no skin pumps are attached, then cut it into smaller pieces. Transfer to a blender, add water, and blend until really smooth in batches.
Stain the content. And then add water to wash the residue twice and strain again. Wash the starch out as more as possible.
Set aside until the starch is settled (if you are not in a hurry, I recommend 4 hours resting). Remove the water on the top and the starch at the bottom.
In order to clean the starch and remove any impurities, add water again and mix well, get a fine cloth, and strain the starch liquid once again. Set overnight. If you find the water above is not clear enough (maybe slightly colored), after most of the starch is settled, you can gently pour off the water and then reload with clean water. No need to stir. After changing the water once or twice, the water should be clean and clear.
Remove the water on top and here we get purified sweet potato starch. Spread the dry with the sun or wind. If there is no sunning day, you can place the starch in the oven and heat it at 50 degrees C until well dried. It is extremely important to dry the starch completely for long storage.
- 1500g pure sweet potatoes , skin already removed and completely cleaned
- water as needed , I use around 7L
- Remove the skin carefully and make sure no skin pumps attached, then cut into smaller pieces. Transfer to a blender, add water to cover the sweet potatoes. Blend until really smooth by batches.
- Strain the content to separate residue and the starch liquid. Wash the residue and strain to separate as more starch as possible.
- Set aside until the starch is settled (I recommend at least 4 hours resting).Remove the water gently above. Add around 1L water, mix well, repeat the straining and settling process (make sure no sand and other impurities contained).
- Set the liquid overnight (Note 1) (long resting time helps to remove the water content in the starch block) and pour off the water above. Here we get the pure sweet potatoes starch. Spread on a tray and dry under sun or bake in oven at 50 degree C until well dried.
- If you want to store the sweet potato starch, drying is extremely important. Well dried sweet potato starch can be easily smashed into powder.