I've been thinking about the fact that although many recipes specify volume, measuring by weight is much more accurate.
Are there any cases where it would be objectively better (i.e. more accurate) to measure by volume – that is where a weight measurement would leave you scratching your head?
I'm really thinking theoretically here: if you're just trying to come up with a reliable, reproducible way to measure an ingredient, perhaps so you can write down a recipe for yourself, would you end up always using weight or are there cases where volume would be more precise? Cases where they are equally accurate (such as water) don't count.
This question is not regarding the practicality of different ways of measuring but rather the accuracy.
I've thought of a few borderline cases, but I was wondering if there was anything more straightforward:
- When serving a whole "unit" as a portion, such as a baked apple, one would count the number of apples to prepare rather than getting a total weight – although it would probably be a good idea to weigh them afterward to figure out how much of the other ingredients to use.
- A garnish might be measured by volume – it doesn't really matter how much the whipped cream on top of the brownie weighs as long as it covers it.
- When greasing a pan, one needs the volume necessary to cover the pan, but no one ever measures this.
Reminder: This question is not about what's subjectively better, or what you think I "should" do, just what's accurate.
Update: I guess I started a bit of an interesting discussion here, but there are only a couple answers that gets even close to what I was looking for. I'll try again:
An person preparing food in a kitchen somewhere on dry land on earth, can measure most items by either weight or volume. In some of those cases weight will be more reproducible than volume (such as flour or salt) and in some of those cases there will be no difference (such as water). Are there any cases where using weight will cause more difficulty than volume – that is the volume is more relevant than the weight.
Two more cases:
- when filling something (say a pie shell) or making equal layers (thank you rackandboneman and rumtscho) if the mousse came out more or less dense than you intended, you need to use the same volume, and the weight is irrelevant.
- when the ingredient is not so precise to begin with, such as "x mL jarred tomato sauce" will surely cover the pasta, but "y g jarred tomato sauce" may not
Again, no question about practicality or personal preference here.
Best Answer
Better is a subjective term, however you can see what is done in practice as a guide to what people think is generally efficient as a balance of preparation speed, accuracy and cleanup.
Many recipes use a combination of volume and weight. Volume for most liquid measurements like milk, water or stock is considered more efficient than weighing them because although weighing is more accurate in most recipes the differences are small enough not to make a difference.
Weight is generally considered more efficient than volume for larger quantities of dry ingredients or gels (butter, lard, shortening) as it's faster, more accurate, and less cleanup.
Small amounts of wet and dry ingredients like spices, herbs, powders, flavorings etc are usually measured using volume measurements like teaspoons and tablespoons. I've tried it both ways and I've found that using teaspoon fractions is much faster than trying to weigh out small amounts of ingredients, and that my scale isn't accurate enough to weigh the fractions of grams you'd need to get that level of accuracy.