I am constantly faced with the problem of determining how much fat to add to the meat I am going to grind for sausage. As many of you know most recipes call for the raw sausage to contain a certain percentage of fat usually around 20%. As a rule I have usually cut just the visible fat from the meat and weigh it separately from the muscle meat to determine the percentage of fat. I was a bit bored this morning and started playing around with the question "how do you determine the amount of fat in a cut of meat". I decided to look at the density of the cut of meat.
Goggle says the density of fat is about 900g/liter of volume that's the reason it floats
the density of muscle tissue is 1060 g/liter of volume the reason pure muscle meat does not float.
The density of water is 1000g/liter
Playing around with a bit of simple math I have calculated that a piece of meat with 85% muscle and 15% fat, placed in a bucket of water will suspend. Meaning that it will neither sink nor float. To determine the percentage of fat in cuts that float (have more than 15% fat) you will need to submerge the cut of meat (with a very small cross sectional probe like a bamboo skewer) and measure the volume of water displaced to determine the volume of the cut of meat. Using this volume you can calculate the total percentage of fat in the cut of meat.
Please humor me and either debunk this method and supply a fairly accurate way to determine the amount of fat in a cut of meat or expand on my train of thought.
Edited by alblancher - 9/6/10 at 8:08am