Slow cooking

What it can and cannot do

A slow cooker cannot brown. It never gets hot enough and it is full of steam, and browning requires a dry surface above 140°C. So anything that goes in raw comes out having only ever been stewed, which is why unbrowned slow-cooker food tastes flat and looks grey.

It also cannot reduce. The lid seals, condensed steam runs back in, and the liquid level goes up rather than down over eight hours. Meat and vegetables release their own water on top of whatever you added, which is why slow-cooker recipes that were adapted from oven recipes end up as soup.

What it can do, better than almost anything, is hold a large piece of tough meat at a gentle temperature for eight hours while nobody is at home. That is a genuinely useful thing and it is worth arranging the rest of the recipe around it.

Getting good results

• Brown everything first, in a pan. Meat, onions, tomato purée. This is the single difference between a good slow-cooker dish and a dull one, and it costs ten minutes.
• Use much less liquid than an oven recipe — often half or less. Nothing evaporates.
• Put root vegetables at the bottom, where it is hottest. They cook more slowly than meat does, which surprises people.
• Add dairy, cream, fresh herbs and green vegetables in the last half hour, or they disintegrate.
• Do not lift the lid. Each time you do, it takes a long while to recover the temperature.
• Thicken at the end — take the lid off for the last thirty minutes on high, or lift the meat out and reduce the liquid in a pan.
• Finish with acid and seasoning. Eight hours flattens flavours; a splash of vinegar and a proper salt check at the end brings it back.

What suits it

Excellent

Pork shoulder, beef shin, brisket, lamb shoulder, oxtail, chicken thighs, dried beans, dals, stocks.

Fine

Chillies, curries, ragùs, soups — all better if browned first.

Poor

Lean meat, chicken breast, fish, pasta, rice, anything that should be crisp.

Impossible

Anything that needs a crust, a reduction, or a roast surface.

A useful hybrid

Slow cooker for the long cook, then a hot oven or a grill for twenty minutes at the end to colour the surface. Pulled pork is much better done this way.

Why food comes out pale

A slow cooker tops out somewhere around a gentle simmer and its interior is saturated with steam. Browning needs a dry surface above roughly 140°C, and neither condition is ever met, so nothing that goes in raw comes out having been anything but stewed.

That is not a fault in the appliance — it is the same physics that makes a braise a braise. What it means is that the browning has to happen somewhere else, in a frying pan, before the pot is loaded. Ten minutes of hard browning in batches gives the finished dish the depth that eight hours of gentle heat cannot create on its own.

The same applies at the other end. A slow cooker cannot crisp a surface, so anything that should have one — pulled pork, a shoulder of lamb — benefits from twenty minutes under a hot grill or in a hot oven after the long cook.

Common questions