Fish is one of the most expensive things in the shopping basket and, if it’s cut carelessly, one of the things that gets wasted most. This is the criterion I work by to make the most of it.
The criterion: the most meat, without damaging it
The idea is always the same: separate as much meat as possible from the skin, without damaging the meat or the product. Every scrap left stuck to the skin is food you paid for that never reaches the plate.
Scales and bones: with tweezers
For the scales and bones of the fish I use tweezers, so as not to damage the meat when removing them.
Why it matters: trim loss and cost
What is lost when cleaning and cutting is called trim loss (merma in Spanish kitchens), and it makes every serving more expensive even if you can’t see it on the receipt. I changed the way and the technique I use to cut fish because I was wasting a lot. If you want to know what each serving really costs you, see the article on costing at home.
How to tell whether you’re doing better
- Weigh the piece before cleaning it.
- Weigh the clean meat when you finish.
- Calculate the trim loss: (starting weight − clean weight) ÷ starting weight.
- Write it down and compare the next time you cut fish. If it goes down, you’re on the right track.
You can enter that percentage straight into the costing calculator.
This text covers the criterion, not a step-by-step filleting guide.
How to choose fresh fish
Before you cut, the thing that gives you the most yield is starting with a good piece. According to the FDA, these are the signs of freshness:
- Smell: fresh and mild. It should not smell strong, sour or like ammonia.
- Eyes, on a whole fish: clear and shiny, and the gills red.
- Flesh: firm; when you press it with a finger, it springs back.
How to store it until you cut it
Keep fresh fish in the fridge at 40 °F (4 °C) or below and use it within two days of buying it; if you will not get to it in time, wrap it well and freeze it. To thaw it, the best way is overnight in the fridge; if you are in a hurry, put it in a sealed bag in cold water.
Hygiene and safety when handling it
- Use a board and a knife for raw fish, separate from what is eaten uncooked, and wash them with hot water and soap when you finish.
- Wash your hands for at least 20 seconds with soap and water after touching raw fish.
- When cooking it, the center should reach 145 °F (63 °C). Without a thermometer, it is done when the flesh separates easily with a fork.
Make use of what you trim
Trimmings and bones do not have to end up in the trash. With clean heads, bones and trimmings (no guts or gills), onion, leek and water you can make a simple fish stock in under half an hour, a base for rice dishes and soups. Clean meat trimmings are good for croquettes, meatballs or fillings. That way, what you lose when cleaning goes from waste to food you actually use, and your cost per serving improves.
From the kitchen · 7 years on the jobTweezers for the scales and the bones, and always the same goal: as much meat as possible, without damaging the product.
Sources and review
- The author’s experience and general cooking criteria (cutting approach, yield loss).
- FDA: Selecting and Serving Fresh and Frozen Seafood Safely (signs of freshness; fridge at 40 °F or below and use within 2 days; 145 °F; 20-second hand washing)
Last reviewed: October 18, 2026. If you spot a mistake, write to us from the contact page.