Roast potatoes are the bedrock of Sunday lunch and Christmas dinner. More important than the bird or beef or whatever is your centrepiece. Dry, overcooked meat can be rescued with plenty of gravy. Even soggy sprouts can be whizzed to a sumptuous puree with extra butter. Greasy, flabby potatoes though? You’re sunk.
I’m an advocate of getting your spuds boiled and tossed in fat a day ahead – or even pre-roasting them, and just giving them a blast in the oven on the day. It’s a technique that Mary Berry recommends too; she says you can freeze them too. It certainly beats fiddling around with trays of hot fat after a couple of glasses of sherry.
But if we can make them ahead, then it should be perfectly possible for the supermarkets to do that bit of the work for us. And no, there’s no shame in buying in; St Mary and I both agree.
While I’m all for a bit of light compromise in the spirit of Christmas calm, the roasties still need to be fantastic. Well flavoured, cracklingly crisp, a fluffy interior waiting to soak up the gravy while maintaining its crunchy, savoury shell. A light glistening of fat is important, too: while no one wants greasy spuds, a biscuit-dry potato is almost as bad.
Are ready-made roast potatoes up to the mark? There’s certainly a good range available. Tesco alone has eight different own-label roast potatoes listed on its website. All the supermarkets do at least one frozen version, and one more expensive fresh, ready-to-roast pack (often in a recyclable foil container) – it means you won’t even need a roasting tin, but only works well if the potatoes aren’t crowded. You may get a crisper result if you tip the spuds into a larger tin to roast.
Supermarket roast potatoes come in a variety of fats: plant (sunflower oil, rapeseed oil, palm oil or a mixture), butter, beef, goose and duck. The fat matters, mostly because of the flavour it imparts. If the pack says goose or duck fat, for example, then it’s reasonable to expect a particular savoury poultry flavour. If it’s beef fat, I want to taste a hint of rib roast. A lot of the versions I tried had only a dollop of the advertised fat (they get away with this by saying “with xxx fat” rather than “in xxx fat”) with the rest made up with sunflower or rapeseed oil. The flavour, unsurprisingly, suffers.
When it comes to the rest of the ingredients, you might think that potatoes, fat and salt would cover it. Think again. Some I tried had over a dozen ingredients, including flavouring, colour, raising agents and dextrose. Many had some sort of starch to help with crisping. Even respected chefs add a bit of semolina when shaking up the spuds, but potato starch, rice flour, pea flour, cornflour and rice starch feels like overkill – and those starches are industrial ingredients which are markers for ultra-processed food (UPF). Not only that, they often result in a strange biscuit-like coating that’s dry and solid rather than crisp. On the whole, the frozen roast potatoes contain more additives than the chilled ready-to-roast kind, but it is definitely worth scrutinising the label.
The other problem with the supermarket range was the potatoes themselves. Several had a depressing cardboardy taste, the kind that develops if you try reheating Sunday’s leftover spuds on Thursday. Turns out this is a well-recognised phenomenon among food scientists: Off Potato Flavour. OPF is a result of the oxidation of linoleic and linolenic acid in the potatoes, and it probably happens when the potatoes aren’t stored well.
I tried a haul of 26 different pre-prepared roast potatoes, both fresh and frozen. My usual tasting rules applied, and some of you have asked how it works (skip the next couple of paragraphs if minutiae bore you).
My twenty-something daughter, who has worked in professional kitchens, runs the show. I’m sent out of the room while the packaging is removed, à la Bake Off’s Technical Challenge, and every product is allocated a code. They’re cooked according to the instructions on the packet (yup, that’s a lot of labelled baking trays) then dished up onto a plate marked only with their code. Because so many roast potatoes were undercooked in the specified time, we did second batches with extra few minutes to give them the best chance of crispness. Come Sunday lunch, or Christmas dinner, I’d recommend factoring in at least another 20 minutes in the oven for optimum results.
For the tasting, I and my fellow tasters (in this case food writer and fermentation expert Caroline Gilmartin) have no idea which brand we are trying, what the ingredients are or how much it costs. Scores are allocated purely on taste, and if one is borderline we then look at price and a value consideration kicks in: a potato that is a very good three, possibly a four, might have its score confirmed as four if it is inexpensive and so exceptional value, but stick at three if it’s pricey. When it comes to picking the top and bottom three, I also take into consideration ingredients, such as whether any mark it out as a UPF. Does that seem fair? Let me know in the comments online.
The taste test
M&S Roast Potatoes with Salted Butter (chilled)
£3.50 for 450g at Ocado (£7.78/kg)
Slightly waxy, rather than fluffy, texture and the flavour is old. The potatoes are a strange dark beige colour inside – perhaps they have been stored badly. There’s more rapeseed oil than butter in these.
Morrisons The Best Beef Fat Roast Potatoes (frozen)
£2.75 for 800g (£3.44/kg)
An oddly burnt flavour with hints of melted plastic. The exterior of these is speckled like it’s been sprayed, and it’s a very biscuity crust.
Morrisons Roast Potatoes (frozen)
A nice colour and yellow flesh, but sadly the same plasticky burnt taste as the other Morrisons frozen potatoes.
Aunt Bessie’s Duck Fat Roast Potatoes (frozen)
£4.60 for 700g at Waitrose (£6.58/kg)
These look quite pretty, small domed potatoes. but they aren’t crisp at all, and they have a strange flavour like they have been dipped in Bovril – turns out they do contain “flavouring” alongside dextrose and colour.
Asda Extra Special Beef Dripping Roast Potatoes (frozen)
£2.75 for 800g (£3.44/kg)
The inside is quite fluffy, but somehow wet, too. Quite nice and savoury but they have a slightly singed aftertaste that spoils them.
Aunt Bessie’s Crispy & Fluffy Roast Potatoes (frozen)
£2.50 for 720g at Waitrose (£3.47/kg)
These look exactly the same and are neither crisp nor fluffy. There is a dry crust that’s been added, it seems.
Tesco Roast Potatoes (frozen)
76p for 800g (95p/kg)
They don’t have enough colour on the outside, but a very yellow potato inside. They taste institutional, with a coating that isn’t even attached to the potato.
M&S Maris Piper Roast Potatoes Frozen (frozen)
£2.90 for 800g at Ocado (£3.63/kg)
Large half potatoes, speckled like a 1980s paint effect. However, there is a bit of crispness (when you cut them not when you eat them). The flavour is off, though - definite POF (Potato Off Flavour)
McCain Roast Potatoes (frozen)
£3 for 700g at Ocado (£4.29/kg)
These have an odd taste of badly stored potato, and they taste of bad fat. All a bit sad.
Iceland Ridiculously Crispy Roast Potatoes (frozen)
A lot of these potatoes are whole rather than halved or quartered which means they don’t have edges to crisp - I’m not sure how these could be said to be ridiculously crispy? Another victim of POF, the reheated potato taste.
M&S Food Jersey Royal Roasties (frozen)
£2.90 for 600g at Ocado (£4.83/kg)
You wouldn’t guess they were frozen from the look of them, but they taste really vegetal, like they have been cooked in cabbage water. Inconsistent in flavour, and not what I want from a roast potato.
Asda Crispy Roast Potatoes (frozen)
£1 for 800g (£1.25/kg)
Medium-small in size and pale yellow inside. The flavour is not great, though, underseasoned and dull.
Tesco Finest Beef Dripping Roast Potatoes (frozen)
£2.75 for 800g (£3.44/kg)
Very white. A slightly wet potato and need extra time in the oven. Not bad for frozen potatoes but not as good as the chilled Tesco Finest ones below.
Tesco Finest Lemon And Thyme Roast Potatoes (chilled)
£2.75 for 450g (£6.88/kg)
The herbs are very prominent but the potatoes are not crisp enough. Fine for a weekday supper but not for a special meal. On the upside, the ingredients list is pretty good.
Waitrose Roast Potatoes (chilled)
£3 for 450g (£6.70/kg)
Large potatoes, so they deliver a high proportion of fluffy inside if that’s what you are after, but despite the nice flavour they are really rather dry. They look too pale, and need an extra 20-30 minutes to colour properly.
Asda Crisp & Fluffy Roast Potatoes (chilled)
£1.20 for 400g (£3/kg)
These end up rather anaemic looking. There’s a bit of crunchy, chewy texture to the biscuity coating, but not the best flavoured potatoes and waxy textured.
Aldi Specially Selected Beef Dripping Roast Potatoes
Neat, and a good colour. Potatoes have a decent flavour and they have got a savoury crust. Not thrilling though.
Tesco Seasoned Roast Potatoes (chilled)
£2 for 800g (£2.50/kg)
Lots of golden patches, so they look the part. Nice crisp-flavoured edges and a hint of herbs, but I want more crunch on the sides of potatoes.
Aunt Bessie’s Mini Homestyle Roasties (frozen)
£3.30 for 700g at Waitrose (£4.72/kg)
Lovely colour and they are crisp and savoury. Quite small, so you get a lot of crust for your spud.
Iceland Luxury The Perfect Beef Dripping Roast Potatoes (frozen)
£4.50 for 800g (£5.63/kg)
These are packaged to compete with chilled premium potatoes, complete with a foil tray. They’ve got that speckled, sprayed appearance, and a nice glisten of fat once roasted, although some of the potatoes seemed a bit underdone inside. On the bland side.
Lidl Deluxe Roast Potatoes with Duck Fat (frozen)
They have a ducky flavour and nice crispness given extra time in the oven, although they’re a little wet in the middle. The best frozen option but they contain 14 ingredients, including palm oil, which is a shame.
M&S Food Ultimate Roast Potatoes with Goose Fat (chilled)
£3.50 for 450g at Ocado (£7.8/kg)
These were one of the few potatoes which browned well all over without needing to be turned over. Nicely seasoned, with a fluffy inside, but slightly sweet flavoured and not as rich as I like, despite being quite high in fat.
Co-op Irresistible Beef Dripping Roast Potatoes (frozen)
£3.19 for 750g (£4.25/kg)
These are biscuity on the outside and the inside is nice and fluffy, with a pleasant flavour. Will soak up your gravy nicely.
Tesco Finest Beef Dripping Roast Potatoes (chilled)
£3 for 800g (£3.75/kg)
A nice herby flavour and a shiny exterior which gives them a homemade feel. They do need more space though; they aren’t crisp enough. If you are looking for a crunchy roast potato these aren’t for you - they’ve got more of a sauté potato texture, slightly greasy, with very uneven colouring.
Asda Extra Special Beef Dripping Maris Piper Roast Potatoes (chilled)
£1.50 for 400g (£3.75/kg)
Lovely flavour, even if they are slightly wet, rather than fluffy, inside. They need extra time to get them really crisp but the result is worth the wait. Roasted in a mixture of butter and dripping, with salt and potato flakes – no nasties.
Sainsbury’s Taste The Difference Roast Potatoes with Goose Fat (chilled)
£2.75 for 450g (£6.11/kg)
These both look and taste the part with a good, even golden colour and a deep goosey flavour, plus, hallelujah, there are just three ingredients – potatoes, goose fat, salt. Give them an extra 20 minutes for maximum crispness.