Bread

Bread needs four things: flour, water, salt and yeast. For every five hundred grams of flour, take three hundred and fifty grams of water, ten grams of salt and five grams of yeast.

Bread $=$ flour $+$ water $+$ salt $+$ yeast. Per $500$ g flour: $350$ g water, $10$ g salt, $5$ g yeast. Water/flour $=0.7$.

bread $=f(F,W,S,Y)$ ($F$ flour, $W$ water, $S$ salt, $Y$ yeast). $F:W:S:Y=500:350:10:5$, $W/F=0.7$.

Mix, then knead for ten minutes. Leave the dough to rise until it has doubled: about two hours in a warm kitchen, longer in a cold one.

Mix; knead $10$ min. Rise until volume $\times 2$: $\approx 2$ h warm, $>2$ h cold.

mix $\to$ knead $10^{\prime }$ $\to$ rise until $V=2V_0$ ($\approx 2$ h warm, $\uparrow$ if cold).

Shape it, let it rise again for an hour, and bake at two hundred and thirty degrees for thirty-five minutes.

Shape; rise $1$ h; bake at $230{}^{\circ }$C for $35$ min.

shape $\to$ rise $60^{\prime }$ $\to$ bake$(230{}^{\circ }\text{C},35^{\prime })$.

If you want twice the bread, double everything except the time: the oven does not care how many loaves are in it.

$2\times$ bread $\Rightarrow 2\times$ everything except time. Time $/\propto$ number of loaves.

$n$ loaves: $F,W,S,Y\propto n$; $t\ne f(n)$.