Jesser
#1, I agree with Paul. Meat is 70% water, held in place in protein bonds etc. When you freeze it, the ice crystals mess up that bond, and water leaks out. In whole muscle, it only leaks from surface, and interior gets mostly reabsorbed. But in ground meat, it leaks from surface…which is everywhere. I freeze meat in chunks, and try not to do ground frozen.
#2. There are tons of SV threads where folks express opinions on bagged vs unbagged. I probably posted remarks both ways. Some juice gets in water. Cooked sausage, like smoked, has less juice come out, so less worry there for unbagged. Most folks say no loss of smoke flavor. Poaching in water has been the German go-to method, forever. But sometimes if I only hit the smoke for 1 hr or 2, and I want it all, I bag them to be sure all smoke stays on.
– tenderness of casings. Most folks say long drying of casings is what causes toughness. Moist cooking seems to help. I’m not totally sure myself, as I don’t think my casings are tough often enough to form an opinion. Some 8 hr smoked TX hotlinks were tough, won’t do that again.