FORMULA SHELF
37 of 370
The arithmetic behind the work: what to measure, what to type in, and what the answer comes out as. Every formula says what the symbols mean and gives a worked example, so you can check it against a job you have already done.
SHELVES
Kitchen
37 formulas
The only sane way to scale a bread recipe, and the way professional bakers write them. Change the flour and everything scales with it.
A loaf with 1,000 g flour, 700 g water, 200 g starter and 20 g salt is 70% hydration, 20% starter and 2% salt.
More water means a more open crumb and a wetter dough that is harder to handle. A change of 5% hydration changes the dough a lot.
700 g water on 1,000 g flour is 70% hydration.
Colour is not proof. A meat thermometer costs almost nothing and settles every argument about dinner. See Cooking Temperatures.
Chicken breast cooked to 74 C in the thickest part is safe; browned outside and pink inside is not.
Weigh the salt and the water, or measure the water and use the figure for the salt. Ice brine is 20-25% for a fast pickle. See Curing Bacon And Sausages.
To brine a 4 kg chicken at 0.6%: 24 g of salt in 1 L of water.
A boiling thermometer is worth the money. Overcook the jam and it goes tough, undercook it and it runs. See Jam Jelly And Preserves.
Add 1% extra sugar and the set comes at about 62 C instead of 65 C.
Roast the bones first for a deeper flavour, and add the vegetables for the last hour so they do not turn to mush. See Making Stock.
1 kg of bones and 2 kg of cold water gives about 1.5 L of stock after simmering and skimming.
A rough check on a ferment. If the drink is not as strong as the sugar suggested, the yeast ran out of food or something else ate the sugar. See Cider And Perry.
Starting at 1.060 and finishing at 1.000 gives 131 x 0.06 = 7.9% alcohol.
Double acting powder works twice, once in the mix and once in the oven, so it is more forgiving. Do not mix baking powder and bicarbonate of soda together.
A 3 cup cake mix needs 1.5 teaspoons of double acting powder.
The way to know if your cider is fermenting and if your wine is ready. Sugar is the fuel for the yeast, and the falling reading tells you it is running out. See Cider And Perry.
Cider at 8 Brix that falls to 2 Brix has used about 6% of its sugar, and at 15% alcohol it is nearly done.
The number to check a cream job against. See Butter And Cheese.
10 L of double cream gives about 1 kg of butter, plus the buttermilk left over.
Cheddar and hard farmhouse cheeses need about 9-10 litres of milk a kilo. A cream cheese or a cottage cheese needs far less. See Butter And Cheese.
100 L of milk makes about 11 kg of cheddar and 90 L of whey.
For working out what to charge at a gate sale or a market stall, and for seeing which dish actually earns.
A batch costing 34 euro that makes 20 portions costs 1.70 a portion.
A warm kitchen gives you a fast loaf and a sour one. The dough temperature at mixing decides how long you wait, not the clock on the wall.
Dough at 26 C: 4 - 4.5 = about 2.9 hours to double, roughly half a normal rise.
For planning a dehydrator run and for expecting how much you will have in the jar at the end of it.
10 kg of apples make about 1.5 kg of dried rings.
Weighing the eggs is the only reliable way, because the sizes in one box vary. A big egg in a cake is a wetter cake.
A recipe for 3 medium eggs (150 g) needs 3 large eggs (180 g) or 2.8 large eggs, so 3.
The number that tells you whether a mill is worth setting up. See Home Milling.
100 kg of clean wheat gives about 72 kg of white flour and 28 kg of bran and germ.
The whole of food safety in one line. See Food Safety In The Kitchen.
A stew left on the table for 3 hours in summer is not safe, however long you then keep it in the fridge.
The honest test of whether you need a bigger freezer or fewer chickens.
A 60 kg dressed chicken is about 120 portions of 0.4 L each, so 48 L of freezer space.
Ghee keeps for months in a warm kitchen, which is why it is the useful one. See Butter And Cheese.
1 kg of cream gives about 100 g of butter and 100 g of ghee if you make the ghee from the butter.
The rules that decide what goes in the freezer. Label everything with the date and what it is.
A joint frozen for 12 months is still good, but it has lost its water and is better as a stew.
Anything more and the extra sugar sits at the bottom of the jar. For a simple syrup, dissolve equal weights of sugar and water and stop there.
A 1:1 syrup by weight is 50% sugar; a 1:2 syrup by weight is 33%.
Weight is the only honest way to judge a rise, because a warm kitchen and a cold one both look different. Mark the bowl or use the scale.
800 g of dough that has gone to 1,000 g has risen 25%, which is a third of the way there.
Lime makes the maize release its niacin, which is the whole point of treating it. See Flint Corn And Popcorn.
1 kg of maize and 1 L of water with 15 g of lime makes about 1.1 kg of nixtamal.
How to work out how much fat ends up in a pie crust, and how to make it flaky instead of short. See Pastry And Pies.
A 500 g flour, 200 g butter pastry will have about 18% fat by weight.
The test of a good flint variety, and the reason some maize will not pop at all. See Flint Corn And Popcorn.
200 g of popcorn makes about 7 litres of popped corn, which fills a large bowl.
A 1:5:5 feed doubles in 4-6 hours at 24 C. A 1:10:10 takes 8-12 hours and tastes less sour.
100 g of ripe starter at 100% hydration is 50 g flour and 50 g water, so it makes 100 g of dough weight.
Resting lets the juice spread back into the meat. Cut it early and the juice ends up on the board.
A 90 minute roast rests for 30 minutes before carving.
Weigh the rice and the water and the result is the same every time. Salt the water, and let it rest before you cook it.
500 g of rice with 750 ml of water makes about 1.6 kg of cooked rice.
Weigh the vegetables, then weigh the salt. Too much salt stops the ferment, too little lets mould in. See Kraut And Kimchi.
2 kg of cabbage at 2% is 40 g of salt, and the finished jar weighs 2.04 kg before the water.
More salt does not mean better bread, it means a firmer crumb and a slower rise. Never add salt straight onto a wild yeast starter.
20 g of salt on 1 kg of flour is 2%.
The quickest kitchen arithmetic. Divide by the factor for a smaller batch, and remember that a double batch does not cook in double the time.
A recipe for 6 with 300 g of flour, baked for 25 minutes: for 4, multiply by 0.67, so 200 g of flour and about 20 minutes.
Smoking is about getting the smoke into the meat and holding the temperature. See Curing Bacon And Sausages.
A rolled bacon of 2 kg takes about 10 hours of hot smoking at 70 C.
Honey is about 80% sugar and 20% water, and it is stickier, so cakes brown more and keep longer. Reduce the liquid in any recipe where you swap it in.
A cake with 150 g of sugar takes 120 g of honey and 30 g less water.
High pectin fruits like gooseberries and redcurrants need less sugar. Soft fruit such as strawberries need more, and more sugar means a firmer set.
2 kg of gooseberries with a litre of water needs about 1 kg of sugar.
Good tempering gives a snap and a shine. A bad one gives a grey dull surface and blooms later. See Working With Chocolate.
Dark chocolate at 45 C cooled to 31 C and worked back to 32 C sets with a shine.
The acid does the preserving. If you cannot get a 5% vinegar, make a brine pickle instead. See Kraut And Kimchi.
500 ml of 5% vinegar covers 1 kg of vegetables, but submerge them fully.
Warm the milk to 45 C, cool to 40 C, add the starter and keep it warm. See Yoghurt And Kefir.
5 L of milk at 45 C with 100 ml of starter, kept at 45 C for 8 hours, gives about 5 kg of yoghurt.
SOURCES & PROVENANCE
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This page is an AI-organised index. The label means the grouping and cross-links were compiled with AI; the information itself comes from the public-domain books, reports and manuals listed below. Open any source to read the local copy or follow the link to the original publication.