Liquid (stock, water, wine):
It is not necessary to use more than ½ to 1 cup liquid in most instances since juices in meats and vegetables are retained more in slow cooking than in conventional cooking.
Excess liquid can be reduced and concentrated for great flavor. You can reduce excess liquid by (1) slow cooking on the stovetop (2) removing meat and vegetables from stoneware (3) stirring in cornstarch, tapioca or tapioca powder and setting the slow cooker to HIGH approximately 15 minutes until juices are thickened.
Milk, cream and sour cream:
Add during the last 15 minutes of cooking time.