Before reading this article, we recommend reading understanding vendor item conversions for food costing first.

Now that you understand how items are costed using mapped vendor purchase details, let's explore how item conversions, prep methods, and yields further refine costing.

Conversions come into play when you need to switch between unit types - for example, converting volume to weight. If you purchase Red Peppers in pounds (a weight unit) but want to use them in recipes as cups (a volume unit), a conversion is necessary.

Conversions are often linked to a prep method. For instance, when converting red peppers from weight to volume, they're likely chopped, and different prep methods can yield different conversion results. While many built-in conversions in opsi include a prep method, one is not always required.

Red pepper conversions example:

Also, prep methods typically have a yield amount associated to them. Yield is the % of total usable amount after preparing or cooking. In the above conversions example, both chopped and sliced red peppers would yield about 84% (after coring, deseeding, and trimming). This means that the cost of your item, when used in a recipe alongside any of those prep methods, will be 16% higher in price because that percent of the item is unusable.

​Red pepper prep methods and yields example:

Lastly, items also have a primary yield field. If specified, this yield will always be factored when costing, whether or not there is a prep method defined. If a prep method is defined, however, the yield associated to that prep method will override the primary yield.

Now that we covered conversions, prep methods and yields, let's learn how to create them!