Made of 100% natural, a combination of rice flour and wheat, âedible strawâ is the name that young people gave to these straws. In cold drinks, rice straws can be used for 4-10 hours, and for hot drinks, they can last 2-3 hours. In particular, They have not used colorings as the regular straws, this rice flour straw is dyed from completely natural materials such as spinach leaves, beetroot, black sesame â¦