Why is there a conversion chart for butter/margarine to olive oil? Do you do that for all cooking recipes?
The conversion chart is more for cake and pastry recipes where quantities are critical.
You can't convert all recipes from solid shortening (butter/margarine) to liquid shortening (olive oil/vegetable oil). For instance, a cake frosting must stay solid at room temperature so a quick frosting made with butter and powdered sugar would work, olive oil and powdered sugar wouldn't.
Then there is the taste. A mild tasting late harvest olive oil would probably work OK in most cake and pastry recipes because cooking will get rid of the aromatic olive oil flavors. Uncooked confections such as the cake frosting would taste more than a bit unusual if made with olive oil.
For most main course dishes where margarine or butter is being used for frying or sautéing, olive oil could be readily substituted. In olive oil producing countries the flavors of olive oil and butter/margarine are used to enhance each other in some recipes.
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