Add 1 cup of uncooked rice to a small plastic baggie and add a few drops of food coloring to the bag. If using gel coloring, you’ll only need a tiny bit.
Add 1 teaspoon of white vinegar to the bag, seal the top, and shake up the bag to mix the color around the rice.
When the color is evenly mixed, dump it out onto a piece of wax paper, spread it out thinly, and let it dry. The rice will feel dry in under an hour, but you can also wait until the next day to use it.
Keep your rice in an airtight container when not in use to preserve the lifespan. I know some people have gotten years of use from one batch, so it’s possible to keep it for a long time!
Notes
You can make rainbow rice by skipping the vinegar and adding a few drops of paint to the bag instead of the food coloring. But the addition of the vinegar helps preserve the rice and keeps it from getting moldy longer.I didn’t really notice a smell of vinegar once the rice was dry (and I have a pretty sensitive nose), if you are wondering about that.It also seems like the paint method coats the rice in a more opaque way while the dye looks a little more translucent, so that’s also a visual preference.