Leeks yield: how much is usable after prep (AP to EP %)
Leeks: about 44% usable going whole to the white and pale green, with a published range of 35–58%. That is a cost factor of 2.27: for every kilo you need ready to use, buy 2.27 kg as purchased.
Yield by preparation stage
| Stage | Average | Range | What is lost | USDA item |
|---|---|---|---|---|
| Whole → bulb and lower leaf (white and pale green) | 44% | 35–58% | Tops (about 46%), root ends and skin | 1412 |
Less than half a leek is the white and pale green you cook with. If you use the dark tops in stock, cost the leek on the whole weight and treat the stock as a by-product.
Prep notes
Trim the root, cut off the dark tops where the colour changes, then split lengthways and wash under running water: grit hides between the layers. Keep the knife angled so you take the tough tops but not the pale green, which is where most of the flavour is.
What the yield does to the cost
Fresh leeks, 4.5 kg at £11.49 (JJ Foodservice, 10 Oct 2026) is £2.55 a kilo as purchased. At 44% usable that is £5.80 per usable kilo.
Worked example: a 100 g side of buttered leeks needs 227 g as purchased, costing 58p. Costed on the bought weight it would read 26p, so the costing would be 56% light: 32p a portion, or £32.50 over 100 portions.
| Usable leeks needed | Buy (as purchased) at 44% |
|---|---|
| 1 kg | 2.27 kg |
| 5 kg | 11.36 kg |
| 10 kg | 22.73 kg |
Use 44% in the yield calculator →
Typical uses
Leek and potato soup, buttered leeks, leek and cheese sauce for gratins, pie fillings and as a softer stand-in for onion.
Storage and the trim
Keep unwashed in the fridge, loosely wrapped so the smell does not travel; about a week. Washed and sliced, use within two days. The dark green tops are good in stock and in a slow-cooked soup base, which is the only place that 56% earns anything back.
Yield source: USDA Agriculture Handbook No. 102, Food Yields Summarized by Different Stages of Preparation (Matthews and Garrison, USDA Agricultural Research Service, 1975), Table 1, item 1412 (US samples of whole raw leeks). Prices as stated, read on 10 Oct 2026. Your own case is the real number: weigh it in the yield calculator.
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