OK but, how did they figure out that they had precisely 3.3 tsp of baking powder? What kind of measurement device would tell you that? 3.25, yes. 3.5, yes. Because you have quarter and half tsp measuring spoons, but no spoons to measure a decimal portion of volume.
For baking powder, eye-balling a fraction of a teaspoon in that spoon is good enough for baking. Use weight instead (for all ingredients) if you want any kind of precision and accuracy; measure in grams to make scaling easier. Once you learn this, you’ll never want to go back to cups and spoons.
Tell the author. They were measuring in teaspoons and claimed they had 3.3 tsp.
…this gotta be a joke, right?
You mean about the proportion working for all values? No joke. If you think about it, it has to work like that since the two scales are fixed. You set the relationship between them once and leave it in that position, then you are just looking at different points along the scale to see the corresponding number on the other scale. So 1/2 = 2/4 = 3/6 etc.
I remember when I was a kid my uncle had a slide rule and showed me how to use it. It was amazing how many different kind of calculations you could do. Of course I’ve forgotten most of what he said, but I remember how cool it was.
Slide rules are great, but I genuinely do not think they’d be useful in a kitchen. And it’s blatantly obvious the author does not cook at all.
When cooking, most of the time you’re eyeballing things. If that is not reasonable, you’ll probably not scale the recipe up or down at all, but annotate it in a way it outputs a sensibly sized batch. And when you are scaling things up/down, most of the time you’re halving or doubling it, you don’t need tools for this sort of mental maths. So the opportunity to use that slide rule (or even a calculator) in the kitchen are actually fairly small.
Plus the examples feel really off:
maybe the recipe calls for 80 g of butter but you only have 57 g
Depending on the recipe you’d add 23g of veg oil or lard instead, to sub the missing butter. Or you’d go out and buy more. Or even better, you’d check if you got 80g of butter, before you even start. But you typically don’t want to scale the recipe ~30% down like this, it means 30% less output. And ultimately, you care about the output.
The picture above was taken while following a recipe that called for 2 tsp of baking powder, and I wanted to make as large a batch as I could given the remaining 3.3 tsp of baking powder I had – a proportion of 2:3.3
This in special smells like bullshit from a distance.
In the most charitable interpretation, “3.3 tsp” is actually 3 1/3 tsp. (0.333… ≃ 0.3). But people don’t measure teaspoons by the thirds, at most by halves or quarters (because 1tsp = 2 coffee spoons, so it’s trivial to measure 1/4 tsp).
If those were tablespoons it could work, as 3 1/3 Tbsp = 10 tsp. But nobody uses whole tablespoons for baking powder, unless they’re making a huge batch of something, and if doing it they’ll likely do it by weight and plan it beforehand.
Finally… baking powder is not the sort of ingredient you’d feel pressed to use completely, even at the expense of other ingredients. It doesn’t spoil, it doesn’t take a lot of space, and it’s dirty cheap. A sensible person in such a situation would simply use 2tsp of baking powder, not scale the recipe at all, and then leave the 1.3tsp leftover for the next recipe.
