If a box of frozen product says "60 grams", that is not what reaches the plate. Part of the weight is lost during cooking, and when that loss is not accounted for the portion cost comes out wrong.
Where does cooking loss come from?
There are three sources, and their shares vary by product.
The first is water evaporation. In the oven, water turns to steam at the surface and inside the product and leaves. That is the largest item.
The second is fat melting and running off. In meat products and laminated doughs some fat runs onto the tray.
The third is ice sublimation. In a frozen product, surface ice can turn straight to vapour without melting.
Most of the loss is water, and that depends on the initial moisture of the product.
Moist products lose more; dry products less.
What are typical rates by product group?
These values are a starting point; measurement is needed for each product.
In leavened doughs the loss runs ten to fifteen percent. Poğaça, simit and bread belong here.
In laminated products it is higher: fifteen to twenty-two percent. Croissants and puff pastry leave some fat on the tray.
In cakes and biscuits the loss is eight to twelve percent. Sugar and fat bind water, so evaporation is limited.
In meat products the loss is highest: twenty to thirty-five percent. Water and fat are lost together.
In frozen fries it reaches twenty-five to thirty percent; water evaporates rapidly in the fryer.
| Product group | Typical loss | Main source |
|---|---|---|
| Cakes, biscuits | 8-12% | Water vapour |
| Leavened dough | 10-15% | Water vapour |
| Laminated dough | 15-22% | Water + fat |
| Frozen fries | 25-30% | Water vapour |
| Meat products | 20-35% | Water + fat |
How is it measured?
There is a simple method and it needs doing once.
Weigh five pieces individually while raw and note the total.
Cook them by your normal method. The measurement has to happen under real conditions; do not use a different temperature for the test.
Weigh again once the pieces have cooled fully. Weighing while hot gives a false result; product loses moisture as it cools too.
Calculate the loss: raw weight minus cooked weight, divided by raw weight, multiplied by a hundred.
Take the average across five pieces. Measuring a single item is misleading.
Do this separately for each product and write it down. A measurement made once serves for months.
How is it reflected in portion cost?
The calculation takes two steps.
Step one: find the real portion weight. If the menu offers 50 grams and the loss is fifteen percent, you need 59 grams of raw product.
Step two: multiply that weight by the unit price. At 120 lira a kilogram, 59 grams costs 7.08.
Calculating on 50 grams directly gives 6 lira; the gap is eighteen percent.
In a high-volume business that gap runs to thousands of lira a month.
The same calculation affects order quantities. A hundred portions a day needs 5.9 kilograms, not 5.
Can the loss be reduced?
Partly, and there are four methods.
The first is optimising oven temperature. Too high a temperature dries the surface fast and drives off more water than necessary.
The second is shortening the time. Once the colour target is reached, every extra minute in the oven is additional loss.
The third is using steam. In some products, steam in the first minutes delays surface drying and lowers loss. It is not used in products where a crisp crust is wanted, such as simit.
The fourth is tray layout. Products spread too thinly lose more; with more airflow, drying accelerates.
Reducing loss to zero is not possible; cooking is by definition a process of removing water.
What does excessive loss indicate?
If your measured loss sits well above the typical range, something is wrong.
The first possibility is that the oven runs hotter than the dial says. Verify with an oven thermometer; deviations of up to 20 degrees are common in both domestic and commercial ovens.
The second is over-baking. Staff may be extending the time.
The third is that the product thawed and refroze. In that case it has already lost water and loses more during cooking.
The fourth is damaged packaging. Product left exposed dries in the freezer.
The fifth is a change of supplier. A different formulation means a different loss rate.
Do results vary between ovens?
Markedly, and that is a problem in multi-site businesses.
Convection ovens produce more loss. The fan continuously removes the humid layer at the surface and accelerates evaporation.
In static ovens the loss is lower but baking takes longer.
In steam ovens the loss is lowest; with high ambient humidity, evaporation slows.
Measurement should therefore be done for each oven. A central recipe gives different results on different equipment.
Measuring by site also explains why the same product costs different amounts at different branches.
How often should it be repeated?
Once a year is enough, but it should be repeated immediately in three situations.
The first is a change of supplier or product. A new product needs a new measurement.
The second is a change of equipment. A new oven means a new loss rate.
The third is a clear complaint or cost deviation. If portions look small or costs run above expectation, measurement is the first checkpoint.
Write the results on the recipe card. The card should carry both raw and cooked weights.
That card is also used directly in training new staff; it gives a written figure instead of a guess.
