The slow cooker is that kitchen appliance everyone seems to own yet few utilize to it's true potential - myself included. More often than not it's sitting on a shelf accumulating dust instead of saving me time and cooking my meals - all in one pot. I think it's especially good for soups and so, here are a few tips to get you motivated to cooking soup in your slow cooker.
1) Your ingredients should all be about the same size. That way, they all cook in about the same amount of time.
2) Start adding items to the pot with those that take the longest to cook. This might include meat or root vegetables.
3) For more flavor, brown your ingredients first. This is especially true with meat and the mirepoix (base flavor) veggies like carrots, onion and celery.
4) Add starches like pasta near the end of cooking. Pasta, and some grains, tend to expand and inflate when overcooked. You could always cook them separately and add in, as well.
5) Add delicate ingredients near the end of cooking. Greens and peas, for instance, otherwise you might end up with mush.
6) Add dairy items near the end of cooking. Such as cream or milk.
7) Start with less liquid. Just use enough to cover the ingredients in the pot. You can always add in more later. Slow cooking actually results in little evaporation. You might not even have room for all of the liquid in the traditional recipe anyway.
8) Experiment with cooking times
I usually like to cook on low for an extended period of time in my slow cooker. But, I've learned that slow on one cooker is not necessarily the same as another. I've been especially happy with the model pictured above that allows for setting a specific amount of cooking time and will then automatically switch to the warm setting. If you feel your cooker isn't reliable I suggest investing in a digital model like this one.
Try adapting any of these soup recipes to work in your slow cooker.