What's the plural form of self-rising flour? Here's the word you're looking for.
Answer
The noun self-rising flour can be countable or uncountable.
In more general, commonly used, contexts, the plural form will also be self-rising flour.
However, in more specific contexts, the plural form can also be self-rising flours e.g. in reference to various types of self-rising flours
or a collection of self-rising flours.