How to Use an Aga Cooker: A Beginner's Guide to Heat-Storage Cooking

In Short…

An Aga is a heat-storage cooker, not a conventional oven. It is always on, has no on-off switches per zone on traditional models, and uses fixed-temperature cooking zones rather than dialled-in heat. You find the right heat by choosing the right oven or hotplate, not by adjusting a setting. The boiling plate is for rapid heat, the simmering plate for gentle. The roasting oven is hottest, the simmering oven coolest. Modern electric conversions break these rules and add programmable control on top.

At a glance: the seven principles

1. An Aga is always on. No waiting for ovens to heat up.
2. There are no zone switches on traditional models. Hotplates and ovens are at fixed running temperatures.
3. You find the heat, you don’t set it. Move food between zones to control cooking temperature.
4. Always close the lids. Open lids waste heat and reduce efficiency.
5. Use partial offsetting on the hotplates. Half-on, half-off the plate keeps a pan ticking over.
6. Start and transfer. Bring up to heat on the boiling plate, finish in the simmering oven.
7. Cold shelves shield from above. Use them to protect items from over-browning at the top of the roasting oven.

Key facts

• The Aga cooker was invented in 1922 by Nobel Prize-winning Swedish physicist Gustaf Dalén as a heat-storage cooker.¹
• The original Aga ran on coal or anthracite. Modern Agas run on oil, gas, electric or solid fuel.¹
• A traditional 2-oven Aga has two hotplates and two ovens. A 4-oven model has two hotplates and four ovens.
• Modern electric conversions like ElectricKit Advanced and eControl Series X-Squared make individual zones programmable and switchable, removing the always-on requirement.
• A typical 2-oven oil Aga uses approximately 40 litres of kerosene per week when run year-round.¹

Definitions

• Heat-storage cooker. A range cooker with a cast-iron core that holds heat for hours, releasing it steadily to ovens and hotplates.
• Boiling plate. The high-temperature hotplate (around 240°C), used for rapid boiling, frying and grilling.
• Simmering plate. The lower-temperature hotplate (around 130°C), used for gentler heat.
• Roasting oven. The hottest oven, around 240°C.
• Baking oven. Medium oven, around 180°C (3-oven and 4-oven models).
• Simmering oven. Low oven, around 100–135°C.
• Warming oven. Lowest oven, around 80°C (4-oven models).
• Cold shelf. A heavy cast-iron shelf used as a thermal barrier from above.

The mindset shift: heat-storage vs conventional cooker

If you have only used conventional gas or electric cookers, the most important thing to understand about an Aga is that you don’t preheat anything. The cooker is already at full operating temperature when you walk into the kitchen, and it has been there since it was last turned on, possibly months ago.

This changes how you cook. There is no “switch the oven on, wait, then put the food in.” You open the door, put the food in, close the door. That is it. The cast-iron core radiates heat that has been stored continuously, so the temperature recovery after opening the door is faster than a conventional oven.

The trade-off is that you cannot change the temperature of an oven on a traditional Aga. Each oven is a fixed-temperature zone, and you choose which zone to use based on what you are cooking.

Modern electric conversions like the ones we fit at John Wray remove this restriction. Each oven can be programmed independently, switched on and off on demand, and brought up to temperature in 30 to 50 minutes from cold. Read more on our Aga electric conversion page.

The hotplates explained

The boiling plate (left)

This is the rapid-heat plate. Use it for:

• Bringing pans of water to the boil
• Stir-frying
• Searing meat
• Deep-fat frying
• Browning vegetables
• The famous criss-cross toast trick (place buttered bread directly on a hot plate, close the lid, flip after 30 seconds)

The boiling plate runs at around 240°C in operation. Items cook quickly here.

The simmering plate (right)

This is the gentler plate. Use it for:

• Sauces and reductions
• Warming milk
• Pancakes
• Lighter frying (eggs, fish)
• Toasted sandwiches (using non-stick liner sheets)
• Holding pans warm

The simmering plate runs at around 130°C. Useful as a flat-iron-style griddle when you place food directly on the surface with a non-stick liner.

Always close the lids when you finish using a hotplate. An open lid radiates heat into the room and reduces oven temperature elsewhere in the cooker.

The ovens explained

The ovens of a traditional Aga are at fixed temperatures. Pick the oven that matches the cooking job, not the other way round.

For a detailed temperature chart and recipe conversion guide, see our Aga oven temperature guide.

Find the heat, don’t set it

This is the most important principle for new Aga owners. Heat is found by position, not by dial. Within a single oven there is a substantial temperature gradient from top to bottom: the top of the roasting oven is hottest, the bottom coolest. Within the simmering oven, the bottom shelf is the gentlest place in the entire cooker.

Practical applications:

• Need a fast brown crust on a roast? Top of the roasting oven.
• Need to bake bread evenly? Middle of the baking oven, or middle of the roasting oven with a cold shelf above.
• Need to slow-cook overnight? Bottom of the simmering oven, sometimes with a heat-diffusing tray underneath.
• Need to keep food warm without overcooking? Bottom of the warming oven on 4-oven models.

Partial offsetting on the hotplates

A small but powerful trick. Once you have brought a pan of water to a boil on the boiling plate, you can keep it bubbling by moving the pan halfway off the plate so half of it sits on the cooler enamelled top. This:

• Maintains a gentle simmer rather than a rolling boil
• Frees up plate space for another pan
• Reduces energy use without removing the pan from heat entirely

You can also do this on the simmering plate to drop a sauce from a steady simmer to a gentle warm.

Start and transfer

The classic Aga sequence:

1. Bring a casserole or stock to the boil on the boiling plate.
2. Once at temperature, transfer the pan to the simmering oven.
3. Leave it for hours or overnight.

This frees up the hotplate immediately for other tasks while the long-cook food finishes in the oven. Many Aga households do all their casseroles, stocks and slow roasts this way.

Shielding and cold shelves

The roasting oven heats most strongly from above. If you are cooking something that would over-brown on top before cooking through, you have two options:

1. Move the food lower in the oven so it sits further from the top heat
2. Place a cold shelf above it, which absorbs heat from above and protects the food

The cold shelf is one of the most useful pieces of equipment that comes with an Aga. Keep one outside the oven so it is genuinely cold when you need it.

Common beginner mistakes

• Leaving lids up. Wastes heat across the whole cooker.
• Using the simmering plate for fast frying. It is too cool. Frustration follows.
• Trying to “preheat” an Aga oven. It is already at temperature.
• Treating the roasting oven like a conventional oven set to 240°C. It is, but the heat distribution is different. Cookery books written for conventional ovens often need adjustment.
• Opening doors unnecessarily. Each open releases heat the cast iron then has to recover.
• Cooking from the front rim of the simmering plate. The plate is hottest in the middle.

Modern electric Agas: what changes

If you have a modern electric conversion (ElectricKit, eControl), most of the principles above still apply because the cast-iron heat-storage core is the same. What changes:

• You can switch individual ovens and hotplates off. Save money when not cooking.
• Heat-up from cold takes 30 to 50 minutes, depending on the system. The eControl Series X-Squared, for example, reaches 220°C in just 8 minutes from ECO mode.
• Pizza Mode on some hob upgrades reaches up to 375°C, hotter than the traditional roasting oven.
• App and smartphone control let you preheat from elsewhere or schedule cooking ahead.

For the full comparison of the two top-tier conversion systems, see our ElectricKit Advanced vs eControl Series X-Squared page.

Frequently asked questions

How long does it take to learn to cook on an Aga?
A few weeks of regular cooking. The principles are simple but unfamiliar. Most owners say after a month they would not go back.

What is the easiest first dish to cook on an Aga?
Baked potatoes in the roasting oven. They are nearly impossible to mess up and demonstrate why people love these cookers.

Do I need special pans for an Aga?
No, but heavier-bottomed pans transfer heat more evenly. Pans with metal handles can also be moved into the oven, which is convenient.

Can I use a recipe written for a conventional oven?
Yes, but match the recipe temperature to the closest Aga zone. A recipe at 180°C goes in the baking oven; 240°C in the roasting oven; 100–120°C in the simmering oven.

Does an Aga heat the kitchen?
Yes. Modern Agas radiate enough warmth to be a noticeable kitchen heat source. Traditional always-on Agas can heat a moderately sized kitchen on their own. Many owners value this in winter and consider it a downside in summer.

Is an Aga hard to clean?
No, day to day. The enamel responds to warm soapy water and a soft cloth. For the deeper, baked-on marks see our guide to cleaning an Aga without damaging the enamel.

How much does an Aga cost to run in 2026?
A 2-oven oil Aga running year-round costs approximately £2,330 a year at current UK heating oil prices. A modern eControl Series X-Squared electric conversion typically costs £208 to £468 a year. See our Aga running costs page for the full breakdown.

Where can I learn to cook on an Aga?
Our showroom at Swale Lodge, Brompton on Swale, Richmond DL10 7EQ has cookers running, and we are happy to demonstrate Aga cooking principles to new owners. Call 01748 811030 or book a showroom appointment.