Torrere
Torrere docs · Changing a recipe
Torrere scales a recipe exactly and checks the method
Torrere scales a recipe to anywhere from 1 to 99 servings, or in the recipe's own unit when it has one, like 12 egg bites or two 9-inch pies. Every amount is stored as an exact fraction of the recipe as written, so doubling and then halving gives back the original exactly. When you double a recipe or more, or halve it or less, Torrere also reviews the method for what doesn't scale in a straight line.
Torrere counts servings in the recipe's own unit
A recipe that says "serves 4" scales in servings in Torrere. A recipe that makes pieces, like "makes 12 egg bites", scales in egg bites, and one made in a vessel, like "one 9-inch pie", scales in pies. The control then offers only whole pieces or whole pies, and the line under it says how that divides up. A recipe that makes a volume, like a litre of stock, scales in servings.
Torrere changes servings from one control
The servings control in Torrere is at the top of cook mode, and shows "Serves" and a number or the recipe's own unit. Moving along the strip previews every amount, and Update makes the change. On the start screen, a Serves picker appears once you start typing, so a new recipe is written for the right number from the start. Asking in chat doesn't change the servings; the control does.
Torrere keeps amounts exact
Torrere stores every amount as an exact fraction at the servings the recipe was written for, and never rewrites it when you scale. What you see is that amount multiplied at the moment it's shown. So going from 4 to 7 and back to 4 gives exactly the amounts you started with, and rounding only ever happens on screen.
Torrere reviews the method for big changes
Scaling a recipe to double or more, or to half or less, isn't only arithmetic, so Torrere reads the method again for the new amount. A recipe made in a pan, tin or pie dish is reviewed on every change, because the vessel is what changes. Torrere shows a card for the new servings, then "Recalibrating the recipe", then either a second card with what it changed in the steps or one sentence saying nothing needed to change. The method review is part of Chef; without it, Torrere scales the amounts and says it didn't review the method.
Torrere's scaled changes can be undone
The method review's changes arrive on their own card in Torrere, and that card can be undone like any other. The servings card itself has no undo button: move the servings back instead.