A production plan speaks in recipe quantities. A supplier speaks in cases, bags, bottles, and eaches. A usable shopping list has to translate between them without pretending you can order a fraction of a sealed pack.

Start with the menu and guest count

Scale each dish to the event, including sub-recipes and the quantity intentionally cooked above the guarantee. Keep that planned overage explicit. Hiding it inside an inflated guest count makes the quote and production plan harder to compare later.

Combine the same ingredient

If onions appear in soup, salad, and sauce, add the compatible ingredient needs before converting to purchase packs. Confirm that the records really describe the same product. Red onion, yellow onion, peeled onion, and frozen diced onion should not be merged because their names are similar.

Convert the total into the supplier unit

Suppose the event requires 132 lb of chicken and the selected supplier sells 40 lb cases:

Packs needed = required quantity ÷ quantity per pack
132 lb ÷ 40 lb = 3.3 cases

You cannot order 3.3 sealed cases. Round up to four cases unless the supplier allows a smaller break pack or you deliberately split the order across another approved product.

4 cases × 40 lb = 160 lb purchased
160 lb − 132 lb = 28 lb above the planned need

That difference is useful. It may cover trim and uncertainty already modeled elsewhere, become planned inventory, or signal that a different pack is a better fit. Do not hide it by rewriting the recipe need as 160 lb.

Treat on-hand stock as evidence

Subtract stock only when the number is trustworthy enough for this purchase decision. Record when it was counted and what receipts, uses, or adjustments happened afterward. If the count is stale, show the uncertainty and buy from the gross need or recount.

Group the result by supplier

A working buy list should show:

  • Ingredient and approved product.
  • Total kitchen need in a useful unit.
  • Supplier pack description.
  • Whole packs to order.
  • Quantity the packs provide.
  • Any known on-hand deduction.
  • Need-by date and event context.

The supplier receives an order it can fulfill. The kitchen keeps the recipe quantity it intends to use. Both numbers matter, and they should not be collapsed into one.