I am trying to analyze and tweak all of my recipes using the bakers formulas (I'm reading BakeWise!). I am trying to figure out how much fat is in my recipe. It has shortening (which is 100%) fat but I have no idea what the percentage of fat is in whole milk or sour cream. I have read the container but it is not readily apparent to me. Can you calculate it from the number of calories and fat calories? Am I just being dumb? Any help would be greatly appreciated!
Whole/homo milk is usually about 3.25% and regular sour cream comes in the range of 12 - 16% butterfat (about 14 grams per 4 ounce serving).
(I'm going here by the brands we have here locally in my neck of the woods and Canada as a whole I believe. Most of our dairy has it clearly marked on the labels in big writing. Not in your area?)
BTW, I absolutely LOVE the BakeWise book. It's a fantastic read! Try the chocolate sour cream icing, to DIE for.
I just looked it up on Wikipedia for you too. There's a great chart there I've copied here:
Butterfat content U.S. terminology
40% Manufacturers cream
36% Heavy whipping cream
30 36% Whipping cream or Light whipping cream
25% Medium cream
18 30% Light, coffee, or table cream
10.5 18% Half and half
3.25% Whole milk
about 2% 2% or Reduced fat 
1.5 1.8% Semi-skimmed
about 1% 1% or Low fat 
0.0 0.5% Skimmed milk 
In the USA, skimmed milk is also known as "fat free" milk, due to USDA regulations stating that any food with less than ½ gram of fat per serving can be labelled "fat free".
Thank you! Thats exactly what I was looking for. I'm still having a heck of a time analyzing the recipe but at least I have these pieces of info.