In short
The simmering oven is the quiet oven at the bottom of an Aga, running at 110°C to 120°C, and it does more work in a well-run Aga kitchen than the roasting oven does. It is where stews, stocks, porridge, rice, slow roasts and puddings cook without attention, often overnight, and where finished dishes wait until everyone sits down. This guide explains how it works, what belongs in it, and how to use it so that the Aga earns its keep.
What the simmering oven is
An Aga is a heat storage cooker. A single heat source, whether an oil or gas burner, electric elements or a conversion kit, warms a cast iron core, and the ovens are cast iron boxes that take their heat from that core. The roasting oven sits closest to the heat and runs hottest. The simmering oven sits further from it, insulated by the mass of the cooker, and settles at around 110°C to 120°C.
Two things follow from that. First, the heat comes evenly from the floor, walls and roof of the oven, not from a glowing element, so there is no hot spot to catch the bottom of a dish. Second, the oven does not need a fan or a thermostat cycling on and off: it simply holds its temperature for as long as the Aga is running. Our Aga oven temperature guide sets out all the ovens side by side.
Where it sits on each model
- 2-oven Aga: roasting oven on top, simmering oven below. Everything slow happens in the lower oven.
- 3-oven Aga: roasting oven on the left, baking oven top right, simmering oven bottom right.
- 4-oven Aga: roasting oven top left, warming oven below it, baking oven top right, simmering oven bottom right. The warming oven, at 60°C to 90°C, takes over the job of holding plates and finished food, which frees the simmering oven for cooking.
- 5-oven Aga: as the 4-oven, with a slow cooking oven on the right-hand side as well.
Our guide to choosing an Aga explains how the extra ovens change the way you cook.
What to cook in it
The rule of thumb in an Aga kitchen is that anything which starts on a hob or in a hot oven can finish in the simmering oven. Some of the dishes it does best:
- Casseroles and stews. Brown the meat on the boiling plate, add the liquid, bring to a simmer, lid on, and into the simmering oven for three to eight hours. The longer the better for shin, shoulder or cheek.
- Slow roasted joints. Brown a joint in the roasting oven for 20 minutes, then move it to the simmering oven. Pork shoulder, lamb shoulder and a brisket become tender over four to six hours; a rib of beef reaches a perfect pink in two to three.
- Stock and soup. Bones, vegetables and water in a lidded pan, brought to the boil on the hotplate, then left in the simmering oven overnight.
- Rice and grains. Bring rice to the boil in measured water, lid on, and leave it in the simmering oven for 20 minutes. It cannot boil over or stick.
- Porridge. Oats, milk and a pinch of salt in a lidded pan, into the simmering oven last thing at night, and breakfast is made by morning.
- Steamed puddings. A pudding basin in a pan with a few centimetres of boiling water, covered, steams for hours without the water boiling dry.
- Meringues and dried fruit. Meringues bake slowly at this temperature and dry out beautifully. Slices of apple or pear dry overnight on a rack.
- Baked potatoes. Start them in the roasting oven for 30 minutes to crisp the skins, then move them down to the simmering oven, where they will hold for an hour or more. Our jacket potato guide has the full method.
- Root vegetables. Parboiled potatoes, parsnips and carrots can sit in the simmering oven until the roasting oven is free, then go up to crisp.
It is also the oven that lets you serve a roast dinner calmly: the vegetables, the gravy and the carved meat all wait in it while the Yorkshire puddings rise upstairs.
Cooking overnight
Overnight cooking is the simmering oven at its best, and it works because the oven stays at a steady 110°C to 120°C with no element to switch off and nothing that can boil dry.
- Get the dish hot first. Bring stews, stocks and porridge to a simmer on the hotplate before they go in. The simmering oven holds heat; it is slow to add it from cold.
- Use a lid. A tight lid, or foil under the lid, keeps the liquid in. Dishes do not reduce in the simmering oven the way they do on a hob, so use a little less liquid than a recipe written for a conventional oven.
- Fill the oven. On a traditional Aga the heat is already paid for, so an oven with three pans in it costs no more than an empty one.
- Leave it alone. There is nothing to stir and nothing to check. Eight to ten hours is normal; a stock is happy for twelve.
- Think about the morning. A casserole cooked overnight can go into the fridge once cooled and tastes better reheated the next evening, which is how many Aga owners cook for a busy week.
On food safety: the simmering oven holds food above 100°C, well clear of the range where bacteria grow, so an overnight dish is as safe as one cooked in the afternoon, provided the Aga is running normally and the dish was hot when it went in. Do not use the oven this way if the cooker is being switched off overnight.
Mistakes to avoid
- Treating it as a warming drawer. It is a cooking oven. Food left in it carries on cooking, so a finished dish should be held at the bottom of the oven for an hour at most, or moved to the warming oven on a 4-oven model.
- Opening the door to check. Every time the door opens the oven loses heat it is slow to recover. Trust it.
- Expecting it to brown anything. It will not. Colour comes from the roasting oven or the hotplates; the simmering oven is for tenderness.
- Over-filling with liquid. Nothing evaporates in there. A stew that goes in swimming comes out swimming.
- Blaming the oven when the whole cooker is cool. If a four hour stew needs eight, check the roasting oven too. A cooker that is under temperature everywhere usually needs a service, a burner clean or attention to its insulation.
Simmering ovens on converted Agas
An ElectricKit or eControl conversion keeps the Aga’s cast iron ovens and their character, but gives each oven its own control. That changes how the simmering oven is used:
- You can run the simmering oven on its own for an overnight stew while the rest of the cooker is off, which costs a fraction of running a traditional Aga all night.
- You can switch it off in summer and still have the roasting oven for a quick meal.
- The overnight porridge habit survives the conversion: it is one of the dishes customers tell us they would not give up.
Our Aga running costs guide shows what each way of running a converted Aga costs per day.
Frequently asked questions
How hot is the Aga simmering oven?
About 110°C to 120°C, with gentle heat coming from all sides of the oven rather than from an element. It is the oven for slow cooking, steaming and overnight dishes.
What can you cook in the Aga simmering oven?
Casseroles and stews, slow roasted joints after browning, stocks and soups, rice, porridge, steamed puddings, baked potatoes to finish, meringues to dry out, and root vegetables to soften before they go up to the roasting oven. It also warms plates and holds finished dishes.
Can I leave food in the Aga simmering oven overnight?
Yes. Bring the dish up to a simmer on the hotplate or in a hotter oven first, put the lid on, and leave it in the simmering oven for eight hours or more. Porridge, stock, pulled pork and beef stews all cook this way. Because the oven stays above 100°C the food is held at a safe temperature, as long as the Aga is running normally.
Where is the simmering oven on a 2-oven Aga?
It is the lower of the two ovens. On a 3-oven Aga it is the lower right oven below the baking oven, and on a 4-oven Aga it is the lower right oven, with the warming oven below the roasting oven on the left.
Why does my simmering oven seem cool?
The oven is meant to feel gentle: its job is to hold food at a bare simmer. If dishes that normally cook in four hours are taking eight, the cooker as a whole is probably under temperature, which usually means it needs a service or the insulation has settled.
Does an electric conversion have a simmering oven?
Yes. ElectricKit and eControl conversions keep the same ovens, and each oven has its own control, so you can run the simmering oven on its own for an overnight dish without heating the rest of the cooker.
Get more from your Aga
Whether your simmering oven is slower than it used to be, or you would like to run it on its own with an electric conversion, we can help. John Wray Range Cookers has serviced, refurbished and converted Agas across Yorkshire, Cumbria and the North East for over 30 years. Call 01748 811030 or request a callback below.