How do I get good results from a slow cooker?

Browning first, using less liquid, and the timing that makes the difference between a good result and a grey one.

Difficulty: beginner
Time: 30 min
Read: 2 min
Safety: caution

Short answer

Brown the meat and soften the aromatics before they go in, and use about half the liquid a hob recipe calls for — nothing evaporates in a slow cooker. Skipping the browning is why slow cooker food often tastes flat.

A slow cooker is excellent at long gentle cooking and does nothing to develop flavour through browning. That has to happen in a pan first, which is the step most often skipped and the main reason results disappoint.

Safety

Do not put frozen meat into a slow cooker — it spends too long in the bacterial growth range before reaching a safe temperature. Defrost first. Dried kidney beans must be boiled hard for ten minutes before slow cooking, as slow cooking alone does not destroy their toxin.

What you'll need

Slow cooker
Frying pan
Thermometer (optional)

Step by step

Brown the meat in a pan first.It is the single biggest determinant of the result. A slow cooker cannot brown, and a stew made without it tastes noticeably thinner.
Soften the onions and aromatics too.In the same pan, lifting the fond. It takes ten minutes and transforms the finished dish.
Use about half the liquid a hob recipe specifies.Nothing evaporates under a sealed lid. Too much liquid is the second most common reason slow cooker food is disappointing.
Do not lift the lid.Each opening loses a substantial amount of heat and adds significant time. Resist checking.
Layer sensibly.Root vegetables at the bottom where it is hottest, meat above. It sounds counter-intuitive and it cooks more evenly.
Add delicate ingredients near the end.Cream, yoghurt, fresh herbs, peas and pasta in the last twenty to thirty minutes. Added at the start they disintegrate or split.
Never cook from frozen.The food spends too long in the bacterial growth range before it reaches a safe temperature. Defrost thoroughly first.
Thicken and season at the end.The dish will be looser than a hob equivalent. Reduce it, or add a cornflour slurry, then taste and season properly.

Tips

Low for eight hours and high for four are roughly equivalent for most dishes. Low generally gives a better result for tough cuts.
Cheap tough cuts are what slow cookers are for. Lean expensive cuts dry out over long cooking and are wasted.
Dried kidney beans must be boiled hard for ten minutes before slow cooking. This is a genuine safety point, not a texture one.

Common mistakes

Not browning the meat first — The slow cooker cannot brown anything, and browning is where most of the flavour in a stew comes from. It tastes noticeably flat without it.
Using the same amount of liquid as a hob recipe — Nothing evaporates under the lid, so the dish ends up watery and the flavours diluted. Use about half.
Lifting the lid to check — It loses a large amount of heat and adds considerable time. Slow cookers rely on a sealed environment.

Questions people ask

Do I need to brown meat before slow cooking?

It is not required for safety but it makes a substantial difference to flavour. A slow cooker cannot brown, and skipping it is the main reason results taste flat.

Why is my slow cooker food watery?

Nothing evaporates under a sealed lid, so liquid that would have reduced on a hob does not. Use about half the liquid a hob recipe specifies.