Setting Up a Prep List That Reduces Waste
A prep list built from sales forecasts — not habit — is one of the simplest ways to cut waste. Here's how to build a par-based prep system your kitchen will follow.
A waste-reducing prep list tells the kitchen exactly how much of each item to prepare based on a sales forecast and a par level — not on "make a lot to be safe." Set a prep par for every item, count what's on hand, and prep only the difference. That single shift stops the most common cause of avoidable waste: over-prepping on a slow night.
Why "prep extra to be safe" is expensive
Prepping to comfort instead of to demand guarantees waste whenever sales come in soft. Perishable prep — cut produce, sauces, portioned proteins — has a short life, so tonight's over-prep is tomorrow's trash. A par-based list turns prep from a guess into a calculation.
Build a par-based prep list
- Set a prep par for each item — the amount you want ready for a typical service, based on how much you actually sell. Tie it to a sales forecast, not a hunch.
- Count on-hand prepped product before each shift.
- Prep the difference (par minus on-hand), not a fixed batch.
- Adjust the par for the day. A patio Saturday needs more; a rainy Tuesday needs less. Forecast from sales history and the reservation book.
- Date and rotate everything with FIFO so nothing ages out unseen.
| Item | Prep par | On hand | To prep |
|---|---|---|---|
| Diced onion | 8 qt | 3 qt | 5 qt |
| Marinara | 6 qt | 4 qt | 2 qt |
| Portioned chicken | 60 ea | 25 ea | 35 ea |
Make the list work
A prep list only reduces waste if it's followed and kept current. Post it at the station, assign it to a shift, and review it weekly against your waste log. If an item shows up in the trash repeatedly, its par is too high — lower it.
Prep to a forecast, not to a feeling. The kitchen that preps the difference to par throws away a fraction of what the "make plenty" kitchen does.
Forecast prep from real sales
The accuracy of a prep list depends on the sales forecast behind it. Cobblestone POS forecasts demand from your actual sales history and day-of-week patterns, so your prep pars reflect what you'll really sell — and Daisy, its AI assistant, can build the day's prep list from that forecast automatically. It's a free, all-in-one platform for independent restaurants; owners choose it over pricier systems like Toast ($470+/month) because forecasting and labor tools are included. Tie prep pars to your inventory par levels and both waste and stockouts drop.
Frequently asked questions
How do I set the right prep par? Base it on how much of the item you actually sell on a typical day of that type, then refine it as you see leftovers or shortfalls. Adjust up or down using your sales forecast.
Who owns the prep list? Assign it to a specific shift or person each day so counting and prepping-to-par is a defined task, not everyone's vague responsibility.
How do I handle busy vs. slow days? Flex the pars by day using your forecast and reservations. A static prep list wastes on slow days and runs short on busy ones.
The bottom line
The kitchen that preps to a forecast throws away a fraction of what the 'make plenty' kitchen does. A par-based prep list turns prep from a nightly guess into a quick calculation: count on hand, prep the difference, adjust for the day. Post it, assign it, and review it against your waste log, and you'll cut avoidable prep waste while still having everything ready when the rush hits.
Build yours with the free Prep List Template (Excel).
