Slow Cooker Mistakes That Are Ruining Your Meals (And How To Fix Them)

I love their hands-off nature, but so many times I’ve had meh results from my slow cooker. Is it the recipe, or is it just me? Some meals turn out watery, bland, or overcooked. People just love slow cookers, and there’s gotta be a good reason. I’ve always wondered: What have I been doing wrong?

Now that slow cooker season is fully upon us, I decided to be proactive and look a little deeper into the Crock Pot for areas where I could improve. I asked two slow cooker experts about the most common mistakes people make with slow cookers, along with advice on better ways to do things. Here are the five big takeaways I had. Did you already know them, or will they be news to you, too?

1. Using a Slow Cooker That’s Too Big

“One of the biggest—or at least most common—mistakes people make is using a slow cooker that's just too large for the job,” says Liana Krissoff, a cookbook author and editor in Pittsburgh. When using a too-big slow cooker, “you overcook a smaller batch because it's shallower in the cooker.”

Ingredients that are spread out over more surface area get hotter faster in a slow cooker, throwing off those crucial cooking times, as well as potentially cooking ingredients unevenly. That means in an underfilled slow cooker, “you can only leave the cooker going for a few hours rather than a whole day, which kind of negates the whole purpose of a set-it-and-forget-it appliance,” Krisoff says. 

Another downfall of oversized slow cookers: “You have to make an enormous batch of something you get sick of too quickly.” I’ve sure been there before! 

How to fix it: “A snug four-quart model is plenty big for most applications,” Krissoff advises.

2. Cooking Food for Too Long

Beware of recipes that call for adding quick-cooking foods, like shrimp, along with those that take longer, like chicken thighs or potatoes. “Food can definitely get overcooked in a slow cooker,” Krisoff says. 

How to fix it: Thinking of recipes in terms of ingredients can help you strategize about which ones are best for all-day cooking. “Think of it as a hearty soup- and stew-making appliance. If you'd cook the ingredient low and slow on the stovetop, it's a good candidate for a long-cooked slow-cooker meal: chuck roast and brisket, chicken thighs, pork shoulder, dried beans, root vegetables, and collard greens. More delicate foods like fish and shellfish, baby spinach, green peas—these you should add toward the end of cooking and watch carefully so they don't turn to mush or get rubbery. Or, better, just cook those things on the stovetop!”

Sarah Olson of Magical Slow Cooker has been creating recipes for over 12 years and has hundreds of slow cooker recipes on her site. She also advises sturdy, forgivable dishes for meals that you start in the morning and eat in the evening. “If you need something that can cook for a long time, stick with soups or roasts. Anything thick, like a meatloaf or casserole, also doesn’t do well on an all-day cook.”

3. Not Cooking Food Long Enough

There is a flip side to the coin. Some foods, like pot roasts or chicken on the bone, benefit from long cooking. “I hear from a lot of people who think their roast or chicken is overcooked because it turns out tough, but most of the time it’s actually undercooked,” Olson says. “Slow cookers need plenty of low-and-slow time to break down the meat, and if it doesn’t cook long enough, it won’t become tender.” 

How to fix it: For those low-and-slow braising meats, Olson has some reassuring advice. “Don’t stress if your meat goes past the recommended doneness temperature; that extra heat actually helps tenderize roasts and other cuts in the slow cooker.”

4. Using a Slow Cooker To Heat Up Food

I’m embarrassed to say I’ve done this in desperate situations in an ill-equipped kitchen, but it’s not a good idea for food safety, says Olson. “Slow cookers heat up too slowly, so leftovers can stay in the unsafe temperature zone for too long. They’re meant for cooking meals from scratch, not reheating.” 

How to fix it: For liquidy foods, it’s best to reheat on the stovetop by bringing to a full boil and then transferring to a slow cooker for holding the food at serving temperature. For less brothy foods (think jambalaya), go for a microwave reheat. 

Another food safety heads-up: Don’t put frozen food in the slow cooker. It stays in the temperature danger zone too long, creating ideal conditions for foodborne pathogens to party down and multiply. 

5. Keep the Lid On

I’m a serial lid lifter! This habit can strike slow-cooking newbies who are used to often checking pots during stovetop cooking. Olson points out why that’s a bad idea. “Keep the lid on the entire cooking time; every time you open it, you lose heat and end up needing extra cooking time.”  

A good slow cooker’s lid seals in evaporation, and ingredients like meat and vegetables release their own liquid as they cook. This is why some recipes (like this Mexican pulled pork) don’t call for any liquid added to the recipe. It keeps the roast from getting soupy. However, a poorly sealed lid (or one that’s opened too many times) might allow too much liquid to evaporate, leading to scorching on the bottom or uneven cooking.

How to fix it: This one’s easy. Keep peeking to a minimum.