Sharing with you today an easy way to make your own natural food coloring powder from fresh vegetables. This purple sweet potato powder has a purple hue and is perfect for various baked goods and desserts. Homemade vegetable powder is free of additives and preservatives so is safe to use as a food coloring. This purple sweet potato powder is actually more fragrant than store-bought ones. I’ve included both food dehydrator and oven methods so you could choose whatever way that is convenient for you. If your oven doesn’t have the dehydrate function, use the lowest temperature possible to prevent the vegetable from browning (it is not noticeable in this case but it will for light-colored vegetables like pumpkin). I usually end up with about 30% of the original amount after the dehydration, and, depending on the size of your dehydrator/oven, you could always make a bigger batch and store the powder in an airtight container. It will last for 6 months in the freezer. If somehow it picks up moisture and becomes lumpy (but not moldy or stale of course), you could always dry the clumps again in the oven with low temperature. The same drying and grinding method is suitable for other vegetables such as yam (orange or yellow) and pumpkin. For a smooth, powdery finish, make sure to pass the powder through a fine sieve and regrind any larger bits that don’t go through.
Homemade Purple Sweet Potato Powder
Makes about 150 g
2 medium (about 500 g) purple sweet potatoes (I used Okinawan sweet potatoes)
Wash purple sweet potatoes and pat dry. Bake in a 220℃/425℉ preheated oven until fork tender, 40 to 45 minutes (the baking time depends on the size of the purple sweet potatoes). Take out and let cool. Peel off the skins and mash with a fork.
Food dehydrator method:
Spread a thin layer of mashed purple sweet potato onto parchment paper-lined dehydrator trays. Adjust to 55℃/130℉ and dehydrate for 8 to 10 hours until crisp. The thin layer would shatter easily if you try to break it. If there are thicker layers, break off the thinner part then return the thicker ones back into the dehydrator for a longer period.
Spread mashed purple sweet potato in between two sheets of parchment paper and roll thinly, the thinner the better. Use the dehydrate function to dry the layer until crisp and the sweet potato no longer sticks to the paper. The drying time depends on the thickness and moisture level of the sweet potato. Alternatively, dry the layer in a 65℃/150℉preheated oven with fan turned on until crisp.
Break the dried layer into pieces and grind them into powder with a high speed blender. Sieve the powder and return larger bits to the blender and grind again for a smooth and powdery texture. Store powder in an airtight glass jar in a cool, dry space and use within a month. For longer storage, store in the freezer for up to 6 months.