While technically possible, cooking raw meat in a slow cooker requires pre-browning in a skillet for enhanced flavor, golden color, and to prevent excess grease.
Seafood's quick cooking nature makes it unsuitable for the slow cooker, risking overcooking and affecting taste, making alternative cooking methods preferable.
Pasta itself is better prepared on the stovetop, but slow cooker pasta sauces, benefitting from extended cooking times, can be paired with traditionally cooked pasta for an optimal dish.
Starchy rice is best cooked on the stovetop or rice cooker, except for congee, a Chinese dish where rice breaking down into a soupy porridge is desired.
Slow cookers are great for tough meats but not delicate vegetables like spinach; add them near the end of cooking to preserve texture and nutrients.
Avoid slow-cooking boneless, skinless chicken breasts as they may become tough and dry; opt for saucy dishes with thighs instead.
Dairy can curdle when slow-cooked, so add it at the end or as a topping to avoid lumpy results in recipes that call for milk, cream, or yogurt.