On Tuesday, March 28, 2017 at 3:20:26 PM UTC-4, Jon Danniken wrote:
> I am making a spreadsheet to convert volume recipes into weight for my
> cake research. Most of my volume measurements have been consistent with
> listed weights (water, sugar, oil, eggs), but I am finding inaccurate
> results with flour and cocoa.
>
> While I find the standard weight (listed on a number of web pages, and
> on the box itself) of cocoa powder (both Nestle and Hershey) to be 80
> grams per cup, when I weigh a cup I always end up with 65 grams.
> Likewise, my gluten-free flour mix (Namaste) is listed (on the bag) as
> being 138 grams per cup, but when I weigh a cup it comes out to be 120
> grams.
>
> I should note that I am measuring the cocoa powder and flour by spooning
> it into the measuring cup (the same one I used for the ingredients that
> match up with their expected weights) and leveling it off with a
> straight surface (the back of a knife). I should also mention that I am
> not using a sifter, but I wouldn't think that would have such an effect
> on the weight (18% on the cocoa powder and 13 percent on the flour).
>
> Any ideas on what is going on here? Should I trust the listed weights
> or the weights I am coming up with on my own?
>
> Jon

I found that a major problem is the measuring devices and methods. A US measuring cup is 8 ounces. A metric up is 250 gms, or 8.2+ounces. A have a 2 cup device which is exactly 500 gms at 2 cup metric level, but when filled to the 1250 gram line (1 metric cup) weighed 235 gms.

I have done spreadsheets for bread recipes and scaling up or down is easy when everything is metric, but I stayed away from cups as a measurement.

Jim Watson