A fruit and vegetable yield table tells you, for each item you use, how much of what you buy actually reaches the recipe. You build it by weighing: what you buy, what is left after peeling and trimming, and one divided by the other. Three measurements per item give you a number you can trust, and with it you get the real cost per usable kilo: price per kilo ÷ your yield. For lemons and limes you measure millilitres of juice instead of grams.
Why your table and not a published one
Published charts give you a rough idea. But your potatoes are not the ones in that chart. Yield changes with:
- Supplier. One wholesaler sends even, clean potatoes; another sends bruised ones caked in soil.
- Season. Lemons give more or less juice depending on the time of year, and onions arrive drier or fresher.
- Size. A small potato loses more peel per kilo than a big one.
- How you prep. Peeler or knife, rushed or careful.
So the only table worth pricing with is yours. The formula behind it is in the guide to yield percentage.
How to measure, step by step
- Pick the items. Start with what you use every day or in the largest amounts: onions, potatoes, carrots, lemons, avocados.
- Weigh the purchase. Use enough for the measurement to mean something: 2 kg of onions, not one onion.
- Prep as usual. Peel, top and tail, core, seed. Do not do a special careful job for the measurement.
- Weigh what goes into the recipe. You do not need to weigh what you throw away; it falls out of the subtraction.
- Divide. Prepped weight ÷ purchased weight.
- Repeat three times from different deliveries and record the average.
For citrus: weigh 1 kg, juice it with your usual juicer, strain it if you strain it, and measure the juice in a jug.
An example table
This is what your table might look like. The numbers are an example from one kitchen; yours will differ.
| Item | Prep | Bought | Left | Yield | Price | Cost per usable kg |
|---|---|---|---|---|---|---|
| Onions | Peeled, ends off | 2.00 kg | 1.72 kg | 86% | $1.80 per kg | 1.80 ÷ 0.86 = $2.09 |
| Potatoes | Peeled raw | 5.00 kg | 4.10 kg | 82% | $1.40 per kg | 1.40 ÷ 0.82 = $1.71 |
| Carrots | Peeled, tops off | 2.00 kg | 1.70 kg | 85% | $1.60 per kg | 1.60 ÷ 0.85 = $1.88 |
| Avocados | Flesh only | 1.00 kg | 0.66 kg | 66% | $6.00 per kg | 6.00 ÷ 0.66 = $9.09 |
| Pineapple | Flesh only | 2.00 kg | 1.04 kg | 52% | $1.75 per kg | 1.75 ÷ 0.52 = $3.37 |
| Lemons | Juice | 1.00 kg | 300 ml | 300 ml per kg | $4.00 per kg | 4.00 ÷ 0.30 = $13.33 per litre |
Add a date column and a supplier column. That way you see whether one supplier always gives you a lower yield, and whether their cheaper price is really cheaper.
Worked example: soup and lemonade
The soup. A pot of potato and leek soup needs 3 kg of peeled potatoes. With your 82% yield:
- Potatoes to buy: 3.00 ÷ 0.82 = 3.66 kg
- Cost: 3.66 × 1.40 = $5.12
Had you costed 3 kg at the purchase price, you would have got 3.00 × 1.40 = $4.20. That is $0.92 less per pot than it really costs.
The lemonade. Each cup of fresh lemonade uses 50 ml of lemon juice.
- Today: 0.05 × 13.33 = $0.67 per cup
Now suppose lemons go up to $6.00 per kg and, when you measure again, that week's lemons give only 260 ml per kilo.
- Cost per litre of juice: 6.00 ÷ 0.26 = $23.08
- Per cup: 0.05 × 23.08 = $1.15
The juice in each cup now costs 1.15 − 0.67 = $0.48 more. At 600 cups a month, that is $288 a month. If you had looked only at the price per kilo, you would have seen a 50% rise; measuring the juice shows the cost per cup went up by more than 70%, because the lemons also gave less.
Planning for that kind of swing is what the guide to seasonal ingredient prices is about: what to do with the recipe, the price or the buying when an ingredient spikes.
When to measure again
- When you change supplier or market.
- When the season changes for an item that matters to your costs, such as lemons or avocados.
- When a recipe "doesn't stretch" the way it used to.
- When someone new starts doing the prep.
You do not need to measure everything every week. Measure carefully once, then re-measure only the items that carry weight in your costs or that change a lot.
What to do with the table
With the table done, every ingredient in your recipes has a cost per usable kilo, not a shelf price. Use it in your recipe costs, in your shopping list (how much to buy to end up with what you need prepped) and to compare suppliers. The overview of ingredient costs by type shows how it fits with meat, fish and the rest of your kitchen.
Do it with the calculator
The yield calculator gives you the cost per usable kg of each item from its price and prepped weight. Put those costs into the food cost calculator with the rest of the recipe to see the real cost of the dish.
Frequently asked questions
Why not just use a published yield chart?
Because it measured someone else's potatoes, lemons and knife skills. Your yield depends on your supplier, the season and how you prep. A published chart tells you roughly what to expect, not what to price with.
How many times should I measure each item?
At least three times, from different deliveries, and use the average. Then measure again when you change supplier or notice the quality has changed.
How do I measure lemon or lime yield?
In millilitres of juice per kilo. Weigh a kilo, juice it the way you do in service and measure the juice in a measuring jug. Divide the price per kilo by the litres of juice to get the cost per litre.
Do I weigh potatoes before or after cooking?
Weigh the way you work. If you peel them raw, weigh before and after peeling. If you boil them in their skins and peel afterwards, weigh the raw potatoes and then the cooked, peeled ones: that yield covers both steps.