Soups & Stews

Soups and stews are what a slow cooker was built for, and they are also where the appliance is most often used badly.
The common mistake is treating a slow cooker as a pot that happens to be slow. It is not. Almost nothing evaporates under a sealed lid, so a stew recipe written for a stovetop or an oven arrives with far too much liquid. Cut it by roughly half and you will get a stew rather than a thin soup with meat in it.
The second mistake is thickening at the start. Flour and cornstarch behave unpredictably over eight hours. Thicken in the last thirty minutes instead, with a slurry stirred in while the pot is still hot.
Building flavour without a stovetop shortcut
A slow cooker cannot brown anything. It never reaches the temperature where the Maillard reaction happens, which means every bit of roasted depth in a finished stew has to be built before the lid goes on. Sear the meat. Soften the onions in the same pan. Deglaze and pour that liquid in. It is one extra pan and about eight minutes, and it is the difference between a stew that tastes cooked and one that tastes boiled.
Layering
Heat comes from the sides and bottom of the crock, not the top. Root vegetables go at the bottom where it is hottest and where they need the most time. Meat sits above them. Anything delicate, peas, spinach, fresh herbs, goes in during the last few minutes or it turns grey.
Dairy goes in at the end, always. Cream and sour cream split over long cooks. Add them in the final half hour with the heat lowered.
Freezing
Most stews here freeze well and several genuinely improve after a night in the fridge, because the gelatin sets and the flavours settle. Recipes note which ones do and which are better eaten the same day. Potatoes are the usual exception, since they go grainy after freezing.
Chili, potato soup, beef stew and chicken and dumplings are the anchors of this section, each with the cut of meat that suits it and the time that cut actually needs.