34 slow-cooker mistakes you need to AVOID

Avoid these mistakes for slow cooker success

You've remembered to prep your ingredients the night before, everything is in the slow cooker ready to go, and you're looking forward to a hearty meal after work. What could possibly go wrong? Quite a lot, as it happens. While the slow cooker is a fantastic, relatively simple-to-use piece of kitchen kit, you could be making some common mistakes. To help prevent a dinnertime disaster, we've compiled a list of common slow cooker slip-ups – with advice on how to avoid them.

Read on to discover 34 slow cooker mistakes everyone makes, counting down to the most common pitfall of all.

We’ve based our ranking on how common each mistake is, and on the opinions and first-hand knowledge of our team. The list is unavoidably subjective.

34. Not crisping up chicken skin

When you cook chicken pieces in a slow cooker, you won't get the same deliciously crispy skin as you would when roasting or grilling. You have two options here. The first is to remove the skin before cooking, then blast it in an oven separately. Alternatively, once your slow cooker has done its bit, put the chicken under the grill until the skin has crisped up to your liking.

33. Starting and stopping your slow cooker

Starting and stopping your slow cooker isn’t wise. By doing this, you risk the food sitting at unsafe temperatures for too long, which could cause bacteria to grow. If you’ve left your slow cooker off for a few hours (perhaps due to a power outage), it’s best to throw out the contents and start again. Remember that it’s safe to leave your slow cooker on a low heat overnight or if you go out, so it's perfectly fine to leave it unattended for a while.

32. Adding too much salt at the beginning

Salt is an important ingredient that brings out the flavour in whatever you’re cooking. When it comes to adding it to a slow cooker, it can be tempting to start seasoning right away. However, if you put in too much right at the beginning – including salt from sauces, stocks and other seasonings – you could end up with a dish that’s far too salty. Instead, start with less salt at the beginning, and add more at the end.

31. Not greasing to prevent sticking

There’s no need to worry about food sticking with liquid-based recipes such as soups and strews. But with some other dishes, including desserts, it’s something you might need to take into account. Greasing the inside of your slow cooker pot will help to prevent sticking – so be sure to use a non-stick cooking spray, oil or butter when making things like cakes or brownies. Lining the inside of your slow cooker with baking paper or a purpose-made liner can work, too.

30. Skimping on the herbs

When cooking a dish for such a long time, any dried herbs you've added may lose their flavour – especially if you're using a recipe that hasn't been adjusted specifically for a slow cooker. In these circumstances, as a general rule, add an extra 50% on top of what your recipe calls for. So, if it asks for 2 tsp oregano, make it a full tablespoon.

29. Adding fish and seafood too early

Cooking fish and seafood in your slow cooker isn’t a complete no-no – you just have to add them at the right time. Leave them in the pot for too long and they can fall apart, or end up tough and overcooked. Add these ingredients towards the end of your cooking time (usually in the last 30 to 60 minutes or so) for tender and tasty results.

28. Spoiling the sauce

Often end up with a thin, watery sauce? There could be a couple of reasons for this. Firstly, you may have added too much liquid, diluting the flavour. Remember that vegetables and meat release their juices while cooking, too – and that condensation builds up on the lid, dripping back into the dish. If your meal is too watery, try adding an extra stock cube at the end. You could also thicken it with cornflour mixed with cold water, then bring it to the boil on the hob. Tossing meat in flour before browning will also help to thicken your sauce.

27. Adding fresh herbs too early

Adding fresh herbs too early will take away their delicate, aromatic flavour. So, wait until your dish is fully cooked, then stir them in. The only exception is if your recipe asks for a bouquet garni – a bunch of bay leaves, thyme and parsley with stalks. This is typically tied up and cooked in the sauce to add more flavour, then removed at the end of cooking.

26. Getting rice timings wrong

Can you cook rice in your slow cooker? Yes, but it’s crucial that you get the timings right. Firstly, you'll need to know what type of rice you're using. If it’s easy-cook or quick-cooking rice, it’s going to require a lot less cooking time compared to regular long-grain rice. The former will likely need to go into your pot within the last 30 minutes of cooking time, whereas the latter can withstand several hours of cooking without turning to mush.

25. Adding dairy too soon

Dairy products like cream and yogurt will curdle if you add them at the start of cooking, leaving your meal in a lumpy mess. Instead, add any dairy (or alternatives such as coconut milk) around half an hour before the end of the cooking time to allow them to heat through fully without curdling. Full-fat versions tend to hold their consistency better when heated.

24. Overcooking your food

This problem may be down to a couple of issues. Firstly, don't forget to set the timer! It could also be that you need to adjust your recipe. Some slow cooker dishes need a certain amount of time on low, then extra time on high. This is to firstly tenderise, then to speed up the cooking process for less dense ingredients. You may need to experiment a little – but, as a general rule, cooking low and slow is your safest bet for consistent results.

23. Topping with cheese too early

Topping almost any dish with cheese makes it better, but the slow cooker can complicate things. Add your cheese too early, and it can turn into a congealed, gooey mess. Patience is key if you want to create a cheesy topping; if you wait until the last five or 10 minutes of cooking time, the cheese will have time to melt but won’t turn rubbery.

22. Not cleaning your slow cooker thoroughly

Long, slow cooking can cause crusty patches that are a pain to remove. Nonetheless, to ensure that your device lasts longer (and to keep it performing as it should) you should make sure you clean your slow cooker thoroughly every time you use it. To prevent ingredients from sticking during cooking, use an oil spray or kitchen paper dipped in oil to fully coat the inside bowl. Some bowls are dishwasher safe, making them easier to clean.

21. Not checking the temperature

Using a food thermometer to check the internal temperature of your food makes cooking with a slow cooker safer. There are different recommended temperatures for various foods, ranging from 63°C (145°F) for fish to 74°C (165°F) for poultry and leftovers. You should insert the thermometer into the middle of the dish or piece of food to get an accurate reading – and be sure to check different points too, including pieces of meat that are different sizes. Don’t stop at slow cooker meals, though; this is a tip that you should use in all your cooking.

20. Letting the lid ruin your recipe

As condensation builds up on your slow cooker's lid, it drips back onto the surface of the food inside – making a breadcrumb topping, for example, unpleasantly soggy. To avoid this, line the lid of your slow cooker with two layers of kitchen paper to help absorb the steam (you may need to replace it during cooking if it becomes too wet). Alternatively, leave off the topping, add it when the dish is cooked, then flash the whole thing under a hot grill. You'll end up with a better texture this way.

19. Converting a recipe incorrectly

If you want to make a classic oven-cooked recipe in your slow cooker, you should reduce the liquid content by about half – otherwise, the result may be too watery. However, if you're relatively new to slow cooking, it may be best to start with recipes specifically written for a slow cooker.

18. Including too much fat

If you have a large slick of oil on the surface of your finished dish, there are a couple of options to remedy it. Firstly, you could skim it off with a large spoon. Otherwise, you could trim some fat off any meat you plan on adding before cooking. Make sure you're using a cut of meat that lends itself to slow cooking, too – think lamb shanks, chicken thighs and braising steak.

17. Using your slow cooker for pasta

Not all foods can be cooked to perfection in a slow cooker, and pasta is one of them (along with asparagus and some types of fish). Instead, cook your pasta on the hob until it's al dente, then drain it and run it under cold water. Add it to your slow-cooked sauce at the end of cooking time to allow it to heat through. Alternatively, follow a specific slow cooker recipe that sees the pasta cooked quickly (and at a high temperature) in a sauce.

16. Using your slow cooker to reheat food

Slow cookers aren’t recommended for reheating. Although you can use a slow cooker to cook food safely over a long period of time, using one to reheat leftovers will lead to your food sitting in an unsafe temperature range for too long. Of course, you can make use of leftovers that were cooked in your slow cooker originally – just stick to using the hob, microwave or oven to heat them up.

15. Cooking dried beans in a slow cooker

Dried beans need to be prepared in a specific way to break down the protein lectin, which can cause severe digestive problems. You don’t have to worry about this if you’re using tinned beans (which are already cooked), but dried beans can’t be thrown straight into your pot. You'll need to boil them vigorously for 10 minutes before they’re safe to add to your slow cooker. Alternatively, you can soak them overnight and save time on prep.

14. Going too hot

If your slow cooker recipes are consistently coming out overcooked, it's likely your slow cooker is operating at too high a temperature. This happens with domestic ovens, too, which often have hot spots. Experiment by turning your slow cooker down to a lower setting than stated in the recipe – your problem should be solved.

13. Removing the lid

You can smell your slow cooker meal bubbling away, so you lift the lid for a quick peek to check how it's cooking. We've all been there – but removing the lid too often will cause all the heat that's built up inside to escape, making your meal take longer to cook. You should only take the lid off if your recipe requires you to add an ingredient, or to give the mixture a stir.

12. Not defrosting meat properly

If you forget to defrost the meat for your slow cooker recipe, don't be tempted to throw it in anyway and increase the cooking time. Your slow cooker's temperature isn't hot enough to kill potentially harmful bacteria – and you may also end up with meat that's raw in the middle.

11. Using the wrong cut of meat

Keep your fillet and sirloin for the grill! The beauty of the slow cooker is that you can use cheaper cuts of meat (such as braising steak, beef shin and chicken drumsticks), which need to be cooked low and slow to become tender. Expensive cuts will just dry out and become tough if cooked for an extended time.

10. Cooking meat too quickly

You were so looking forward to that meltingly tender, slow-cooked piece of meat, but it's as tough as old boots. Luckily, there's a simple reason for this problem – you probably cooked it on too high a setting for an insufficient time. Remember, long and slow is the key here.

9. Not covering your meat

If you consistently end up with unevenly cooked meat or poultry, it's likely that your ingredients haven't been equally layered or submerged in sufficient liquid. Make sure any denser ingredients (which will take longer to cook) are at the bottom of the slow cooker, and add just enough liquid to cover everything.

8. Treating all vegetables the same

Vegetables that cook relatively quickly on the hob (including courgettes, mushrooms, peas, broad beans and French beans) should be added to the slow cooker around half an hour before the end of cooking time – otherwise, they'll turn out overcooked, mushy and soggy. More robust root vegetables generally work better in slow cooker recipes and can be added sooner.

7. Adding too much liquid

Any liquid you add to your slow cooker should just cover the rest of your ingredients. If you add too much to your recipe, the liquid will cause excess condensation as it heats – and as it can't escape, it'll drip back from the lid into your dish, making it too watery. Ladle out any excess liquid before cooking to make sure you don't have too much to begin with.

6. Not sautéing onions first

You'll get a much better flavour if you sauté the onions for your recipe before adding them to the slow cooker. Otherwise, you may end up with the taste of boiled onions, rather than the soft sweetness you were looking for. If you're making a curry, try sautéing the onions with spices to intensify the flavour, then add them to your slow cooker.

5. Forgetting to brown meat first

Some slow cookers have a browning or sautéing function built in, though older models may not. Browning meat adds texture, colour and flavour, so remember to brown any meat you plan on using over a high heat first, whether on the hob or in your slow cooker. If you skip this step, it's likely the meat will end up tasting boiled and bland.

4. Throwing everything in the pot at the same time

Incorrectly layering ingredients can cause uneven cooking. Begin by placing denser ingredients (such as root vegetables) at the base, which will be closer to the heat of the slow cooker. Adding browned meat and more finely chopped vegetables on top will ensure that everything cooks to perfection at the same time.

3. Underfilling your slow cooker

Do you find that your meat tends to dry out, or that everything overcooks when you use your slow cooker? If you have this problem, it's likely that you've underfilled your slow cooker to less than half full. Instead, always try to keep it two-thirds full. Your slow cooker may also be too big for the recipe, so think about doubling up, then freezing half of it. Using the correct meat matters, too. Generally, slightly fattier (and often cheaper) cuts cook better. For example, chicken breasts are more likely to dry out than legs or thighs.

2. Overfilling your slow cooker

Add too much to your slow cooker, and the contents won't cook evenly – plus, the ingredients could spill out, resulting in a mess. Not only that, but overfilling your slow cooker can also affect the flavour of your dish. When you cook meat and vegetables, they produce liquid, so make sure your cooker is large enough to accommodate the extra volume. As a rule, aim to fill your slow cooker no more than two-thirds full for optimal results.

1. Underestimating your machine's potential

Slow cookers excel at soups, stews and sauces – but that’s not all they can do. If you’re not expanding your slow cooker repertoire beyond these things, you’re missing out. Slow cookers are versatile and can produce a wide range of meals and treats, from curry to cake. Think beyond soups and stews to help your slow cooker reach its full potential; that way, you can use it all year!

Now discover 25 unexpected recipes that work brilliantly in your slow cooker

Last updated by Laura Ellis.