by larry » Wed May 23, 2012 3:23 pm
It should be solid early. When the meat goes into the casing it should be solid but wet. If it's loose and crumbly going in to your curing environment, it won't tighten up over time. All that really happens over time is the moisture comes out. You're probably right about not enough mixing. When you mix, the texture should go from ground meat to a paste where you can still see the difference between fat and meat, but the texture is unified and you can no longer see or feel the little rope shapes of the ground meat and fat. What is happening is that the mixing process releases miosyn or myosin, not sure of the spelling, which makes the mixture sticky and binds it together.
If you've mixed enough, the next challenge is casing the mixture tightly. I tend to want it as tight as possible, so I prick the casing and squeeze, and prick some more and squeeze some more, until I don't see any surface air pockets, and I feel confident that I have removed all the inner air pockets.
If your fat is smearing, make sure it is cold when you grind it. I grind mine fully frozen. Also, make sure your blade is sharp, and is tight against the cutting plate.
I'm sure others will chime in, but you're on the right track.