Have you noticed that most of my recipes list ingredients in grams? I often receive email from people asking if I would convert the grams into ounces, or into volume measurements. I’m sorry I cannot do this on request, but here are some tips that may help you, if you want to do the converting yourself.
I strongly recommend weighing ingredients, especially flour. The reasons for this are explained in my post about scales and weighing. Many scales can switch between avoirdupois (ounces/pounds; the US system) and metric (grams/kilograms; the sane system) units.
If you do not have a scale, or your scale does not have metric units, you will have to do some math. (Remember when you rolled your eyes in 5th-grade math class and complained that you couldn’t imagine when you would ever need this stuff in real life? Now would be a good time.)
If you have a scale, but it does not have metric units:
One ounce is approximately 28.4 grams. So to convert grams to ounces, divide by 28.4. For example:
57 grams = 2 ounces (closely enough)
If you do not have a scale:
The USDA Nutrient Database is a very nice resource for determining weight-volume equivalents for most things.
However, the Nutrient Database will not tell you the weight of a cup of flour. This is because flour measures differently depending on your measuring technique. I have seen a cup of flour weigh anywhere from 127 to 148 grams.
A good place to start might be to use the conversion factor of 130 grams per cup of flour. So to convert grams to cups of flour, divide by 130. If you are consistently unhappy with your baking results, you may need to adjust this number.
Another ingredient the Nutrient Database will not help you with is sourdough starter. The weight of a cup of starter varies with how much the starter is stirred down before it is measured. I measure my mature 100%-hydration starter, after being well-stirred, at about 250 grams per cup of starter. Again, your mileage may vary.
For small ingredients such as salt and yeast, unless you have a scale that can measure to the tenth of a gram, you’ll measure more accurately with volume. For most of my recipes I give both gram and volume measurements for these things, but in case I forgot a few:
For table salt, one teaspoon is 6 grams. (For Kosher salt, a teaspoon weighs less than this.)
For instant yeast, one teaspoon is 3.1 grams.