I freeze the stock in gallon sized freezer bags. Quart bags would work too. Make sure they are freezer bags though and have a double seal.@BReeder! Then how do you store the stock? I tried freezing it in qt jars but it broke, even with a 3" headspace and cooled to room temp or in fridge first. The meat goes in freezer bags, obviously? Thanks.
I strain the stock while warm and then let it cool a but in a large mixing bowl. It doesn't have to be room temp, but you don't want to melt the plastic bag. I then freeze the bag/s flat in the freezer - easier said then done in my packed freezer but a previous slab of frozen stock or a box if pizza or pancakes works as a flat enough surface if you cannot set it flat on a shelf. If you don't want fat in your stock, you could cool the bowl in the fridge before bagging. This causes the fat to solidify on the surface so you can pull it off. Personally, I leave that fat for flavor.