If there's one question which is asked more often than any other on the BBC Food Messageboards, it's probably how to make perfect Yorkshire puddings, and there are always several different answers given as to what is the most important factor - sizzling hot fat, metal tins, very hot oven, the right flour, the only 'celebrity chef' recipe which works for that particular poster etc.
I think one of the problems with answering the question is that, if you have always made good Yorkshire puddings, it's hard to see why others have problems. What could be simpler than a batter made with plain flour, milk and an egg, which is baked in a hot oven until risen, firm and golden? How could anyone not do it?
For me, the only problem during more than 35 years of cooking has been YPs which stick in the tin, and I solved that problem about 10 years ago with one of the, then newly introduced, silicone moulds. The mould I bought can't be heated empty, and doesn't hold heat like metal does anyway, so straight away I abandoned the idea that sizzling fat in a hot metal tin was essential. The hollows in the mould are about 8cm in diameter across the top and just over 1cm deep. When filled to the top with batter this is just the right depth to produce ideal individual puddings. The picture above shows the silicone tray, on it's metal tray, with four moulds containing meat fat ready to receive the batter and the two holes not needed for puddings filled with water to prevent damage to the silicone.
So - what's my recipe? I'm a traditionalist who makes the batter in the same way my mother did, with no weights or measures. I just use a kitchen cutlery tablespoon (not even a calibrated measuring spoon) and my experience. If I want four puddings I use 3 slightly rounded tablespoons of plain flour, and if I want six puddings I heap the spoons a bit more. There are those who claim to make YPs with SR flour, but the odd time I've used SR flour by mistake, my puddings haven't worked, so I would say that plain flour is essential.
I also use only one egg for up to six YPs. My belief is that the British celebrity chefs such as James Martin and Brian Turner, who drastically increase the ratio of eggs to flour in their recipes, do so because they couldn't make traditional puddings either! Yorkshire puddings originated as a cheap, filling part of the meal to cut down on the amount of meat that needed to be served - adding several expensive eggs just wasn't part of cooking cheaply. Delia Smith's recipe, using one egg for every 75g (3 ounces) of flour is close to the ratio of eggs to flour which I use in the batter I make. You can find her recipe and lots more information on Yorkshire puddings on this link.
So, put 3 tablespoons of plain flour into a small bowl and add a pinch of salt. Add 1 large egg and a splash of milk (I use semi skimmed). Using a large spoon, gently mix to a smooth thick paste, adding a little more milk if necessary. Once you have a smooth paste with no lumps, use the spoon to vigorously beat the mixture for a couple of minutes. Then gradually stir in more milk until the consistency of the batter is that of unwhipped double cream. At this point the batter can be left for a while - some cooks think a waiting period of around an hour is essential, but I haven't found much difference between batter left standing and batter used straight away.
If you are using a metal YP tin, put it into the oven with a little of the fat from the roasting meat about 45 minutes before you want to eat, to allow it to get hot. Whatever temperature you are roasting the meat at is fine at this stage - you won't be cooking the YPs until the meat is out of the oven and resting. My oven is usually at 180C/160C fan/Gas 4 at this stage. With my silicone mould, which doesn't need pre-heating, I add a teaspoon of meat fat to each mould just before putting in the batter.
35 minutes before you want to eat, when you have removed the meat from the oven, add the batter to the 'YP tin'. First though, give it a stir, and if you can see that it has thickened during standing, add enough cold water to bring it back to it's original consistency. I fill my YP moulds to the top, so I would advise adding batter to your chosen mould to a depth of about 1 cm:
Carefully transfer the YPs to the oven, using the highest shelf, or hottest position, if you are not using a fan oven. At this stage, turn up the heat to 230C/210C fan/Gas 8 and resist the temptation to open the oven door for at least 20 minutes. A friend gave me the tip that cooking YPs in a rising temperature produced better results, and I tend to agree with her. After 20 minutes, have a peek, without opening the oven door too far; if your puddings are risen and already evenly dark golden, it's OK to turn down the temperature a bit, rather than risk burning them. I think they need to be in the oven for at least 30 minutes so that they become firm enough not to collapse when taken out of the oven.
With a bit of luck, you'll have something similar to the pudding in the photo below, shown as an accompaniment to roast lamb, roast potatoes, roast parsnips and cabbage cooked with shredded leeks. The ideal pudding, for me, should be well risen and crispy around the edges, with a hollow in the centre, but the base should still retain some stodgy, chewy, puddingness - a totally light crispy pudding is wrong.