Cooking and recipes

Scale a recipe to the number of people you’re feeding, turn cups into grams, convert oven temperatures and plan when the roast goes in. Varlig knows what a cup of flour or sugar weighs, so an American recipe works on your kitchen scales.

Scaling a recipe up or down

The lasagne recipe serves 4 and you’re cooking for 10. Set the scale once and multiply each ingredient by it.

calc

# Lasagne: recipe serves 4, cooking for 10

scale = 10 / 4 gives 2.5

beef mince = 500 g * scale gives 1,250 g

passata = 700 g * scale gives 1,750 g

white sauce = 600 mL * scale in L gives 1.5 L

cheddar = 150 g * scale gives 375 g

lasagne sheets = 12 * scale gives 30

Change scale to 6 / 4 or 2 / 4 and every amount follows. Adding in L or in kg tidies up large amounts. For things you can’t cut in half, such as eggs, add rounded up to the line. See Rounding up and down.

Cups to grams

American recipes measure by the cup. Write the amount, the ingredient and in g, then round to whole grams for the scales.

calc

# Banana bread, from an American recipe

2 cups flour in g to 0 dp gives 281 g

0.75 cup brown sugar in g to 0 dp gives 165 g

1 stick of butter in g gives 113 g

1 tsp baking soda in g to 1 dp gives 4.6 g

0.5 cup milk in mL to 0 dp gives 118 mL

Varlig knows the density of more than 80 ingredients, so a cup of flour and a cup of sugar give different weights. A stick of butter is 113 g, as printed on American packs. cup is the US cup; for Australian recipes, write metric cup. See Ingredient weight and volume.

Oven temperatures

Convert a Fahrenheit recipe to Celsius, turn a gas mark into degrees, and take 20 degrees off for a fan oven.

calc

350 °F in °C to 0 dp gives 177 °C

fan = (350 °F in °C) - 20 °C

fan to nearest 10 °C gives 160 °C

# A British recipe says gas mark 4

oven = gas mark 4 gives 180 °C

gas mark 4 in °F gives 350 °F

oven - 20 °C gives 160 °C

Temperature conversions handle the offset between the two scales for you, and to nearest 10 °C gives a setting you can find on the dial. Gas marks follow the UK oven table, so gas mark 4 is 180 °C, or 350 °F on an American oven. See Temperature and Kitchen measures and oven settings.

Timings

The chicken needs 20 minutes per 500 g plus 20 minutes, then 15 minutes’ rest. Work back from when you want to eat.

calc

# Sunday roast, dinner at 7:30pm

chicken = 1.5 kg

roasting = chicken * 20 min/500 g + 20 min gives 80 min

resting = quarter of an hour

roasting in hours and minutes gives 1 hour 20 min

Oven in at: 7:30pm - roasting - resting gives 5:55 PM

20 min/500 g is a rate, so multiplying it by the weight gives a cooking time, and quarter of an hour is 15 minutes, written the way the recipe says it. Subtracting durations from a clock time gives the time to start. See Adding time to a clock time.

Cost per portion

Batch cooking a chilli for the week? Price each ingredient from the shelf price and divide by the portions.

calc

# Chilli for six

beef mince = £6.40/kg * 750 g gives £4.80

tomatoes = 2 tins @ £0.85 gives £1.70

beans = 3 tins @ £0.65 gives £1.95

rice = £1.50/kg * 400 g gives £0.60

veg = £1.75 // onions, peppers and spices

batch = beef mince + tomatoes + beans + rice + veg gives £10.80

portions = 6

batch / portions gives £1.80

takeaway = portions items at £9.50 each

takeaway - batch gives £46.20

A price per kilo times the weight you use gives the cost of that part of the pack. 2 tins @ £0.85 prices the tins and jars you buy by the count, and the last line shows what the batch saves against six takeaways. See Prices per unit.

Make it your own

Write oven temperatures the way recipes print them: 180c in F gives 356 °F, and with oven = gas mark 4, oven - 20c gives the fan setting of 160 °C. See Temperature.
Measure the British way: 2 dessertspoons in ml gives 20 mL, and 1 UK pint in ml gives 568.26125 mL. imperial pint and uk pt work too. See UK and US measures.
Check a bread dough: 350 g is what % of 500 g gives 70% hydration.
Use the rule of three: 200 g is to 4 as what is to 6 scales one ingredient from 4 people to 6. See Proportions.
Cook a smaller batch with scale = 2 / 6, and round the eggs with 3 * scale rounded up.
Scale a single ingredient with a fraction: 3/4 of 500 g or two thirds of 450 g.
Compare two packs on the shelf: £8/kg in £/100g gives £0.80/100 g, the figure printed on most price labels.