Cooking from a French recipe, and the cake that measures itself

French recipes measure by the pot de yaourt, the empty yogurt pot, by sachets that print no weight, and by an oven dial marked one to ten. None of that is a units conversion. It is a set of everyday objects promoted to measures, and the catch is that the most famous one, the yogurt pot, has a fixed volume and a weight nobody agrees on.

The yogurt pot, and the recipe built to measure itself

The classic gateau au yaourt is the first cake a French child bakes, and it needs no scale and no measuring cup. You empty a 125 millilitre pot of yogurt into the bowl, then rinse the pot and use it to scoop everything else: one pot of yogurt, two of sugar, three of flour, half a pot of oil. The tool is the packaging, and because every French fridge holds the same pot, the ratio travels even though the unit is disposable.

That elegance hides the one hard problem on this page. A pot holds 125 millilitres of anything, but a pot of flour does not weigh a fixed number of grams, and French sources do not agree on it. The publisher 750g put three pots of flour on a scale and got 190 grams, about 63 a pot. Baking With The French Tarte weighs a pot of flour at 85 grams, which would make three pots 255. That is a third of a difference on the single most-quoted French kitchen weight, and it exists precisely because the pot was designed to be poured, not converted: as long as you use the same pot for every ingredient the proportions hold, and the grams only start to matter when an English reader tries to pin the recipe to a measuring cup. The oil is looser still, half a pot in most versions and a whole pot in some. Where a bake depends on it, weigh; where it does not, the pot is enough, which was the point of measuring in pots to begin with. The same cake travels: the Spanish bizcocho de yogur and the Argentine torta 1-2-3 measure by the yogurt pot exactly this way, on Spanish and Latin American measurements.

The sachet: French packet weights recipes rarely print

Like a German recipe with its Packchen, a French one asks for un sachet and assumes the packet in your drawer matches the packet in the writer's. Two of them carry most French home baking, and a recipe that names either one usually stops there. Some blogs do print the figure beside the ingredient, at about 11 g for the baking powder, so the weight is findable rather than secret; it is the recipe in front of you that tends to leave it out.

Both come with a caution. The levure chimique is baking powder, and 11 grams is what Alsa and Vahine put in a sachet rather than a national constant: brands run from about 7 grams up, so treat it as enough for 500 g flour and not an exact dose. Sucre vanille has no American shelf equivalent at all; substitute two teaspoons of sugar and a quarter teaspoon of vanilla extract for each sachet. A French recipe will also say levure and mean two entirely different products: levure chimique is baking powder, levure de boulanger is baker's yeast, and reading one as the other leaves a cake flat or a bread inert. The yeast dosing itself is on the yeast converter.

The spoons, the glass and the small liquid units

A cuillere a soupe is 15 millilitres and a cuillere a cafe is 5, the metric tablespoon and teaspoon, so they need no conversion for a European cook and sit one percent off an American one. What does need reading is the fill: a French spoon is rase, level, unless the recipe says bombee, heaped, and the gap is real, since a French chart puts a tablespoon of flour at 12 grams where an American one says about 8. The per-ingredient level and heaped weights are on heaped versus level spoons, and every spoon size beside the French one is on tablespoon sizes by country.

Older recipes measure by the verre a moutarde, the mustard glass, because French mustard was sold in a reusable drinking glass of a standard 200 millilitres, so un verre de farine means that glass, about 100 grams of flour. It sits with the world's other drinking-vessel measures on cup sizes around the world. Liquids bring two units an English converter omits: the centilitre and the decilitre. A centilitre is 10 millilitres, so 25 cl de creme is 250 millilitres, a shade over a US cup; a decilitre is 100, and a recipe in decilitres measures the Scandinavian way, almost everything by the dl.

The oven, the flour bag and the eggs

Three systems a French recipe assumes. The oven may be marked in thermostats, and unlike most dial scales this one is a rule: the thermostat number times 30 is the temperature in Celsius, so thermostat 6 is 180 degrees. It is not the British gas mark 6, which is 200, and that collision is on oven temperatures. The flour bag carries a T-number, T45 for the finest through T150 for wholemeal, grading mineral ash rather than the protein American flour is sorted by, which flour types works through. And an egg that just says oeuf means the European medium grade, which maps to American Large rather than Medium, on egg sizes.

Butter is the one thing that needs no decoding: it comes as a 250 gram plaquette and French recipes ask for it in grams, so there is nothing to convert. The wrapper is marked, and halving it is 125 grams, which our butter master covers beside the American stick.

A recipe, decoded

Read a gateau au yaourt as it is written, in pots, with an American kitchen in mind. This is the whole point of the page in five lines: almost everything is measured by the pot, and the only figures an outsider needs are the ones the pot cannot give.

1 pot de yaourt

A 125 ml pot of plain yogurt, tipped in, then rinsed and kept as the measure for the rest.

2 pots de sucre

Two pots of sugar, scooped with the same pot. Level, not heaped.

3 pots de farine

Three pots of flour. In grams this is the disputed line: about 190 by one weighing, up to 255 by another, against roughly 120 g for a single American cup. Weigh if the cake matters to you.

1/2 pot d'huile

Half a pot of oil, about 62.5 ml. Some cooks use a whole pot, so trust the recipe you have.

1 sachet de levure chimique

11 g of baking powder, about a tablespoon. The recipe will not print the 11.

3 oeufs

Three European medium eggs, which are US Large. US Medium would leave the batter short.

Only the eggs and the sachet ask you to know a number from outside the pot, and only the flour makes you choose between two of them. Everything else the pot settles by itself, which is why a French child can bake this cake before learning to read a scale.

Questions about French measurements

How much does a pot de yaourt hold?

125 millilitres, a little over half a US cup. As a measure its volume is fixed but its weight is not: a pot of flour is reported anywhere from about 63 to 85 grams, because the pot was meant to be poured pot-for-pot, never weighed.

What is one sachet de levure chimique in American terms?

About 11 grams of baking powder, roughly a level tablespoon, dosed for 500 g flour. It is a brand figure rather than a national one: a French chef surveying packets found 7 to 11 grams, so read the sachet as "enough for 500 g of flour" rather than an exact weight.

Is thermostat 6 the same as gas mark 6?

No, and the clash catches people. French thermostat is the number times 30, so thermostat 6 is 180 C. British gas mark 6 is 200 C. Same numeral, 20 degrees apart, which the oven page lays out for all three national scales.

Sources

750g for the weighed yogurt pot, Vahine and Cuisine d'Aubery for the levure chimique sachet and its brand spread, Supertoinette for the cuillere and verre values and the centilitre, and Bricolage.fr for the thermostat rule. The pot, glass, spoon and packet volumes come from our unit registry, each sourced on its own node. Full citations on the sources page.