Understanding heat

TECHNIQUE

Heat is the one variable that runs through almost everything you cook, yet it is the part most home cooks never quite get a feel for. Learn to read it, and read your pan, and half your kitchen problems disappear.

This guide covers the heat levels that matter, how to tell when a pan is ready, and why getting it right transforms your cooking.

Heat control starts with knowing your cooker

A gas cooker gives you immediate visual feedback. Turn the flame up and you can see it respond. Turn it down and the change is instant. For most cooks this is the most intuitive way to cook — the flame tells you what is happening.

An electric cooker is easier to keep clean and maintains a steady temperature well, but you lose the visual element. The hob does not respond instantly — it heats slowly and cools slowly. Learning how quickly your electric rings respond to adjustment is part of learning to cook on them. What reads as medium on the dial may behave differently to the medium on someone else’s cooker.

An induction hob looks similar to electric but behaves differently. The heat is more instant and more intense than a conventional electric ring. It can be extraordinarily responsive but needs to be understood — the same setting that gently simmers on one hob may be far too aggressive on another.

A range or country range is something many cooks aspire to. They are impressive and capable but notoriously difficult to regulate — both on the hob and in the oven. The heat is less precise and more instinctive. Cooking on a range takes time and experience to master.

The principle is the same regardless of what you cook on — know your cooker. A recipe is written in general terms. How it behaves in your kitchen on your heat source is something only you can learn.

The heat levels every cook needs to understand

Heat is not simply on or off, high or low. There is a spectrum, and understanding where on that spectrum you need to be — and being able to hold it there — is one of the most useful skills in a kitchen.

• Gentle warming — the surface of the liquid barely moves. No bubbles. Used for keeping things warm, melting chocolate, or infusing flavours without cooking them.
• Simmer — a constant gentle breaking of the surface with small bubbles. Not a vigorous boil, not a lazy warm. This is the workhorse of cooking — stocks, soups, braises and sauces all spend most of their time here. The proper stock guide explains why a gentle simmer matters for clarity and depth. We named this site partly after it. It matters.
• Rolling simmer — more vigorous than a simmer, with larger bubbles breaking consistently across the surface. Used for reducing a sauce or stock where you want evaporation without the violence of a full boil. The proper sauce guide covers how to reduce without burning or splitting.
• Boiling — full vigorous movement throughout the liquid. For pasta water, blanching vegetables, or anything that needs high heat fast.
• Sautéing — high heat with fat in the pan and food moving. The food should be moving regularly, cooking fast in direct contact with a hot surface.
• Searing — very high heat, minimal movement. The goal is colour and crust. Moving the food too soon or too often prevents this from happening.

Technique tip

To test whether a pan is properly hot before adding oil or food, add a few drops of water. If the drops bead up, roll around the surface and disappear quickly, the pan is at the right temperature. If they sit and steam slowly, the pan needs more time. This takes seconds and saves a lot of disappointing results.

Getting the pan right before anything goes in

One of the most common mistakes in home cooking is adding food to a pan that is not yet hot enough. A cold or lukewarm pan means food steams rather than sears, sticks rather than releases, and colours unevenly or not at all. The choosing pans guide covers which materials hold and distribute heat best.

Heat the pan first. Add the oil or fat once the pan is hot — you will see it shimmer and move fluidly. Then add the food. The sizzle when food hits a properly hot pan is the sound you are looking for. Silence or a gentle hiss means the pan was not ready.

The exception is garlic. Garlic added to a pan that is too hot will brown within seconds and turn bitter before anything else has had a chance to cook. Add garlic after other aromatics, or reduce the heat before it goes in, and watch it constantly.

The mistake most home cooks make with garlic

Adding garlic to a pan that is too hot. Garlic browns in seconds at high heat and once it has burnt the bitterness cannot be fixed. It will flavour everything else in the pan. If this happens the honest answer is to start again. Add garlic after other aromatics, keep the heat moderate, and watch it.

Dry heat and wet heat — understanding the difference

All cooking methods fall into one of two categories.

Dry heat — roasting, grilling, frying, searing — uses hot air, hot metal or hot fat to cook food. It produces colour, crust and caramelisation. It is generally high heat applied relatively fast.

Wet heat — poaching, steaming, braising, simmering — uses liquid or steam to cook food. It is generally lower heat applied over longer time. It cannot exceed 100 degrees Celsius at sea level regardless of how high the flame goes, which is why long slow braises in liquid produce tender rather than charred results.

Many dishes use both — sear a piece of meat in a hot pan first to develop colour and flavour, then braise it slowly in liquid to become tender. The two methods work together.

Understanding your oven

A fan oven circulates hot air around the food, which distributes heat more evenly. A middle shelf position will give you all-around cooking with consistent results. As a general guide, fan oven temperatures run approximately 20 degrees Celsius lower than the conventional temperatures given in most recipes — so a recipe calling for 200 degrees Celsius in a conventional oven is typically cooked at around 180 degrees Celsius in a fan oven. That said, every oven is different and the dial temperature is not always the actual temperature inside.

A conventional oven without a fan has more variation across the space. The top of the oven is significantly hotter than the bottom. Food that needs colour on top goes higher. Food that needs gentle heat without browning goes lower. Understanding where the heat sits in your oven gives you more control, not less.

Whichever oven you use, get to know it. An oven thermometer costs very little and tells you whether what the dial says matches what is actually happening inside. It is one of the most useful small investments in a kitchen.

Visual and sound cues — what to look and listen for

You do not always need a thermometer to understand heat. The food and the pan tell you what you need to know if you pay attention.

Sound — a loud immediate sizzle when food hits the pan means it is hot enough. Silence or a slow gentle hiss means it is not. A simmer has a quiet steady sound. A rolling boil is louder and more insistent.

Sight — oil that shimmers and moves fluidly in the pan is hot. Oil that sits still is not ready. Butter that foams and then the foam subsides is at the right temperature for cooking. Butter that immediately browns is too hot for anything delicate. The surface of a liquid tells you exactly where on the heat spectrum you are — from barely moving to a rolling boil.

Smell — garlic, onions and spices release their aroma as they cook. A sharp acrid smell means the heat is too high. A gentle sweet fragrant smell means you are where you need to be. The how to season food guide explains how aroma and seasoning work together to build flavour.

The mistake most home cooks make

Not getting the pan hot enough before adding food, and then turning the heat up to compensate once the food is already in. Food added to a cold pan sticks, steams and colours unevenly. The time to build heat is before the food goes in, not after. Be patient with the pan. It will tell you when it is ready. The same applies to resting — food taken straight from heat to plate loses its juices immediately. Give it time.

The food thermometer — the most underused tool in a home kitchen

A food thermometer removes the guesswork from the most important question in cooking — is it done. Cutting into a piece of meat to check costs you juice and presentation. Pressing it and guessing takes years of experience to do reliably. A thermometer tells you exactly where you are in seconds.

The principle is simple: it is always better to undercook, measure and return something to the heat than to overcook it and find there is nothing to be done. Overcooked meat, fish or poultry cannot be retrieved. Undercooked food can always go back.

Key internal temperatures to know: Chicken and poultry — 74 degrees Celsius at the thickest point away from bone. Beef and lamb medium rare — 55 to 57 degrees Celsius. Beef and lamb medium — 60 to 63 degrees Celsius. Pork — 70 degrees Celsius. Fish — 60 degrees Celsius though many prefer it pulled slightly before this.

Resting — the step most home cooks skip

Once food comes off the heat it is not finished. Resting allows the juices that have been driven to the centre of the meat during cooking to redistribute through the whole piece. Cut into it immediately and those juices run straight onto the board. Rest it properly and they stay in the meat where they belong.

A steak needs to rest for roughly as long as it was cooked — a steak cooked for four minutes needs four minutes of rest. A larger joint needs longer. Tent it loosely with foil to retain some warmth and leave it alone.

The temperature will also continue to rise slightly during resting — known as carry-over cooking — which is why pulling food from the heat two or three degrees before the target temperature makes sense.

Heat is the part of cooking that no recipe can fully control for you. A recipe can tell you high, medium or low — it cannot know your cooker, your pan, your kitchen. Developing heat awareness is a matter of paying attention every time you cook. Listen to the pan. Watch the oil. Smell what is happening. The more you notice, the more instinctive it becomes.

Frequently asked questions