Stock/Broth Recipe Scaler

Stock and broth sit underneath a great deal of good cooking, and scaling one is not quite as simple as multiplying. The bones-to-water ratio sets the flavour concentration, and the water figure has to allow for hours of evaporation that a written recipe rarely spells out.

Standard stock ratios (per 1 liter / 1 quart of finished stock):

Stock types, bone ratios and cooking times:

Fish and bone broth sit either side of the usual 500 g because they are doing different jobs. Fish stock is a fast, delicate extraction that goes wrong if you push it. Bone broth is the opposite: you want every bit of gelatin out of the bones, so you use more of them and give it a day.

When to use this calculator:

• Scaling a stock recipe for a larger or smaller pot
• Preparing batch stocks for freezing
• Converting restaurant recipes to home quantities
• Planning ingredients for meal prep

Practical example: Ask for 5 litres of chicken stock and you get 2.5 kg of bones, 7.5 litres of water to start with, 750 g of onion, 500 g of carrot, 300 g of celery, 10 cloves of garlic, 5 bay leaves and 25 peppercorns. Everything is derived from the yield you want, so you do not need an existing recipe to scale from: give it the finished volume and it works backwards to the shopping list.

Note the water figure. It is half as much again as the yield, because a stock simmering uncovered for hours loses a good deal to steam. Start with the yield volume and you will finish well short.

Tips:

• Start with cold water. It draws the impurities out slowly, which is what gives you a clear stock rather than a cloudy one.
• Never let it boil. A bare simmer, the odd bubble breaking the surface, is what you want. A rolling boil emulsifies the fat into the liquid and you cannot get it back out.
• Skim the foam and fat off the surface through the first 30 minutes.
• Chill it fast in an ice bath before it goes in the fridge. A warm stockpot sitting on the counter is a textbook bacterial incubator, and the danger zone is wider than most people think.
• It freezes well for up to 6 months. Ice cube trays are the trick for the small quantities a pan sauce needs.
• Of everything on this list, the bones-to-water ratio is what decides whether it tastes of anything.