All-Purpose Flour (Best Option)
1 tablespoon per cup of sauceAll-purpose flour contains moderate protein content, allowing it to thicken tomato sauce effectively by gelatinizing starches when heated. It mimics bread flourβs thickening role without adding excessive gluten, which is unnecessary in sauce.
To use successfully, whisk the flour into a small amount of cold water or oil before adding to the sauce to avoid lumps. Cook the sauce long enough to remove any raw flour taste.
Compared to bread flour, the sauce will have a slightly less chewy texture but remain smooth and well-thickened, making it an excellent substitute.