While a large roast turkey, or a lovely glazed ham is often seen as the main star of a Sunday lunch, or Christmas dinner, I believe that a large tray full of golden roast potatoes covered in flaky sea salt is just as important. As simple as a roast potato may be, there are some tricks you can apply to get the ultimate roast potato. I think everyone agrees that a great roast potato should be nice and golden all over, crunchy on the outside, and soft and fluffy on the inside. But how can you maximize this crunch-to-fluff ratio?
If you want to make the perfect roast potato there are some things to consider: the heat (the oven and fat should be properly hot), the type and size of potato (use a starchy potato and cut them into relatively small bite-size pieces), a quick toss in some flour, or semolina, and the choice of fat. The latter being the main point of interest of this post.
I found some recipes online from some celebrity chefs that all claim to have the recipe for the best ‘roasties’, but somehow, they all make them differently. Most people use a simple olive oil to roast the potatoes in, but olive oil has a low burning point, which could greatly affect the flavor (bitter!) and crunchy outcome of the potatoes. A simple sunflower oil could do the trick, but it is just a bit bland and should better just be used for fries… After all, I am looking for the perfect roast potato for Christmas this year. While many cooks stick with using olive oil, a decent number of cooks swear by using goose fat, while a handful of other cooks seemed to prefer the more affordable duck fat (Ramsay mentions it, for example). Interesting.
Do the animal fats really result in the best roast potato (spoiler: they do!)? And is there really a great difference between goose and duck fat except for the price? Does each fat have a different effect on potatoes? I wanted to find out! In my life, I’ve made many a roast potato with regular vegetable oils and I am sure you’ve done the same. This time, I decided to experiment with just the animal fats, so I got myself a jar of goose fat and a jar of duck fat and proceeded to investigate recipes.
The first issue was deciding how much fat to use in the first place. Nigella Lawson once stated that goose fat is an essential Christmas cooking ingredient and this is definitely the case for her roasted potatoes as she uses the exorbitant amount of about 640 grams of goose fat for 2.5 kilograms of potato. Her other secret ingredient is a bit of semolina to crisp up the outside of the potatoes instead of regular flour. Mary Berry uses 3 – 4 tablespoons (about 51,2 grams) of goose fat for 1.4 kilograms of potato, while Jamie Oliver suggests a mere 4 tablespoons of goose fat for 2.5 kilograms of potato. The differences between the amounts of fat used in each recipe are quite large, especially with Nigella and her 256 grams of fat per 1kg of potato. So, what to do?
The amount of fat used by nigella seemed a bit much to me and my jar of fat didn’t even contain as much, but I am a glutton after all so I couldn’t quite go for a mere couple of tablespoons either. I decided to use 100g of goose fat for one batch of 1kg potatoes and 100g of duck fat for another batch of 1kg of potatoes (for every other added kilogram I would add only about 50g of fat more).
Now on to the fats! Initially, I started off with a smell-test. The goose fat had just a very mild fatty scent, which was almost undetectable, while the duck fat, had a slightly stronger scent, reminiscent of roast duck skin, or bones (yum). I quite liked the mild scent on the duck fat, but others might prefer the more elegant goose fat. Honestly, after being in the oven for an hour, the roast potatoes themselves had none of this ‘ducky smell’ and both dishes just smelled like roast potato.
Heating up the fat before adding the potatoes is a necessary step in creating that perfect roastie. When the potatoes hit the tray, they should immediately sputter and sizzle to instantly crisp up of the outer layer of the potato. Notably, the duck fat seemed to emit more of a ‘roast’ smell while heating up, which I find quite pleasant.
One thing all cooks seemed to agree on is that potatoes for the perfect roasties should be parboiled and ‘fluffed up’, or scratched before being thrown into hot fat. So, while the fat was heating up in the oven (which really needs to be insanely hot), I boiled my potatoes for 8 minutes, just enough to fluff up the outside. You can bash up the outside of the potatoes a bit by vigorously shaking the pan, scratching them with a fork, or slightly squashing them with a potato masher as Jamie Oliver does – doing so creates more little bits and edges that will facilitate that crunch you’re looking for. You then coat the potatoes with a little bit of regular flour, or semolina and dump them (carefully) into the hot fat.
In both batches the potatoes started to crisp up and turn golden relatively quickly, but I did need to move and turn the potatoes around quite a lot to create a nice even golden color on all sides.
Speaking of color: I am quite sure it’s the fault of my old oven, which may or may not be as stable with its temperature at all times, but the ‘duck potatoes’ turned out to be a bit darker than the ‘goose potatoes’ and had to be taken out after 50 minutes instead of the 60 I had planned. Oh, well. Since all ovens are different, just make sure your oven is really hot when your potatoes go in, check on them regularly and take them out when the color is according to your liking.
While the goose fat potatoes had a lighter golden color, the outside was still amazingly crispy and crunchy while the inside was like a buttered mashed potato which melted in your mouth after biting through the initial crunchy exterior. The goose fat left no particular flavor and just left a soft, buttery film around the potato and in the mouth. Very nice.
The duck fat potatoes were quite the same, but for some reason (I am still looking at you, oven) turned out a tad darker and crispier. There was a slight (veeeery slight) difference in flavor from the goose fat, but I can’t quite figure out what it is… I suppose, the goose fat was just being a bit more ‘plain’, or ‘neutral’ for some reason, which some people might prefer. I think I prefer the slight roastiness of the duck fat.
My honest opinions about the result? You may be relieved (or disappointed?) to hear that there isn’t that much of a difference between duck and goose fat (to me). Both fats are nearly exactly the same. It is true, though, that using either of these fats does result in the perfect roast potatoes with a very high ‘crunch-to-fluff’ ratio without the bitterness of olive oil and with an added touch of luxury.
The luxurious goose fat is, of course, a classic (especially during the festive season) and makes a great tray of roast potatoes – also sounds rather impressive when you can tell your guests that the potatoes are ‘roasted in goose fat’. But, honestly, if you can’t find, or afford it, and if you don’t mind the initial slightly ‘roast ducky’ scent of the duck fat (why would you?) I believe the duck fat potatoes are just as luxurious and delicious as the goose fat ones – and I personally just might prefer them.
So, without further ado, here’s my recipe for ‘the best roast potatoes’
The Best Roast Potatoes
- 1kg starchy potatoes
- 100g goose fat, or 100g duck fat (add only 50g more for every additional kg of potato)
- 1 tablespoon plain flour, or semolina
- Flaky sea salt
- Preheat the oven to 200°C.
- In the meantime, peel the potatoes and cut the larger ones into pieces so that all potatoes have an even size (about 4cm).
- When the oven is hot, place the goose-, or duck fat in a roasting tin and place it into the hot oven. Let the fat heat up for about 20 minutes.
- Put the potatoes in a pan filled with cold water and bring to a boil. Let the potatoes boil for 8 minutes.
- Drain the potatoes and put them back into the pot. Let them sit for 2 minutes to let them steam dry.
- Sprinkle on the 2 tablespoons of flour, or semolina. Shake the potatoes around in the pot to coat them with the flour and to bash them up slightly – the ‘fuzzy’ edges is what will help them crisp up later.
- When the fat is hot, carefully transfer the potatoes into the roasting tin and stir well to coat them in the fat. Return the tin to the oven and roast the potatoes for 45 - 60 minutes until they are golden and crispy. If your oven is very hot, they may need less time in the oven to crisp up so keep an eye on them, stirring and turning them around at regular intervals.
- Sprinkle on some flaky sea salt before serving.