I have a recipe that uses self-rising flour which is not available where I live, so I make my own by sifting all-purpose flour, baking powder and salt together. This has always worked fine.
In a few days I will be needing a few cups, so I decided to make it today and store it in a closed plastic bag.
Could it be a problem that I have made the flour a few days in advance? Will it still work as expected?
I have always used the homemade self-rising flour immediately and never tried to store it.
Of course the self-rising flour you buy in stores are the same three ingredients, but I don't know if the manufacture also uses some additives that makes it store well.