Conversions

I am currently working on converting all my recipes from metric weights into US volume measurements.

More often than not, recipes that show both metric and US volume measurements do not give the exact conversion. And in some cases, such as baking, it is vital to get the exact amount of ingredients for it to turn out correctly.

An example taken from one of my favorite books: Baker & Spice, Passion for Baking. Their recipe for hot cross buns stated that I needed 870 g OR 7 cups of flour. When I measured out 7 cups of flour, it weighed 1050 g. That’s an anomaly of 180 g (in excess of 1 cup, which is 20 % more than was required).

Because, I know it’s a British book, I relied on the metric measurements and have worked out the U.S. volume conversion, by weighing, then measuring with the U.S. cups. It’s a long tiresome process and sometimes the conversion will end up with very weird measurements, such as 2/3 cups and 2 T, but I hope that people who want the recipes to work using this measuring system will gain from it.

The problem with the conversions often shown in cookery books, is that they base the fact that 1 cup is 240 ml. The ONLY ingredient you can rely on being 1 g per 1 ml, is water, this is due to its density. That is to say that, 1 cup or 240 ml of water is equivalent to 240 g. There may be other ingredients that come close to that density, but the one you can really rely on is water.

A vital flaw in the cup measuring system is “density”. Density is directly linked to the weight (or more technically correct, mass) and volume. The elementary equation being:

Density = mass/volume

I can explain this more clearly if you imagine 1 cup of rice, then imagine 1 cup of Cheerios. Like for like, weight-wise you would get more rice than you would Cheerios. This is because the Cheerios are lighter and take up more volume than rice, which leads me to say that rice has a higher density than Cheerios. Therefore, one cannot assume that all ingredients if measured in 1 cup will be the same weight, unless they have the same density.

Now that I’ve hopefully explained the issue with the cup system, I have compiled a list of the ingredients I have already measured, with the conversion from cups to grams. All weights correspond to 1 c of the listed ingredients unless otherwise stated. It may seem a little disordered at the moment, that’s because I haven’t had the time to organize them into groups … that will come. When the list is more comprehensive I will also tabulate them in a more presentable manner.

Water, 240 g
Whole almonds, raw, 140 g
Ground almonds, 140 g
Hazelnuts, raw, 135 g
Cashew nuts, raw, 130 g
Sunflower seeds, raw, 150 g
Pumpkin seeds, raw, 150 g
Honey, 340 g
Treacle (molasses), 340 g
Brown sugar, 240 g
Turbinado sugar, 200 g
Sultanas (raisins), 150 g
Rolled oats, 100 g
Puffed brown rice cereal, 16 g
Flour, 150 g
Apple pie spice, 120 g
Apricots, dried, whole, 150 g
Candied peel, diced, 150 g
Walnuts, halves and broken pieces, 110 g
Peanut butter, 280 g
Icing (confectioners) sugar, 120 g
Cocoa powder, 100 g
Rice, dry 190 g
No- fat dry milk powder, 140 g
Butter, 226 g
Wheat germ, 100 g
Green lentils, raw, 200 g
Fine polenta (cornmeal), 200 g
Tahni, 260 g

Butter, 1 stick or 1/2 c = 113 g
Butter, 1T = 15 g
Dry active yeast, 1 T = 11 g
No- fat dry milk powder, 1 T = 8 g
Flour, 1 T = 10 g
Tahini, 1 T = 16 g