When my venison summer sausage is finished there is a fat gel on the outside of the sausage when I take the casing off. When smoking I do not raise the temperature above 170 to prevent a fat out. The final temperature is set at 170 until the internal temperature reaches 152. I then remove the sausage from the smoker and give it an ice bath for 30 minutes. I then hang the sausage for 2 hours after which I put it in the refrigerator overnight. When I take it out of the refrigerator the next morning and take the casing off there is a grease gel on the outside of the sausage. I mix 11 lbs of venison to 4 lbs of pork fat. the casing is also wrinkled not smooth like in the stores. What am I doing or not doing to cause the casing to wrinkle and gel on the sausage. The sausage tastes great.