The science of the festive spud: How to prepare the perfect roast potato for Christmas

11th Dec 2017

No great Christmas dinner is complete without the perfect roastie, but which variety of potato should you pick? Does traditional goose fat make for the crispiest, fluffiest offering or is vegetable oil the way forward?

Christmas dinner is often the most important meal of the year for home cooks. But did you know the art of the perfect roastie goes far beyond ‘to parboil or not to parboil’?

We’ve put together a handy guide of which potato variety – and which oil or fat – gives the best combination to deliver the very best results and will leave your guests full of festive joy.

Selecting the potato variety

Potatoes come in many different varieties but if you’re looking for a great choice for roasting, a ‘floury’ type is definitely the way forward, as this will create the ideal mix of textures once it’s cooked. Great potato choices that are readily available from your local supermarket are Maris Piper or King Edward.  

King Edward

This classic spud variety has been around since the early 1900s, making it one of Britain’s oldest commercially-grown potatoes. Known for its distinctive pink-blushed creamy skin and floury texture, it is the traditional variety for great roasties.

Maris Piper

When it comes to the crunch – as in, a wonderfully crunchy outside – the Maris Piper has fast become a firm favourite at the festive dinner table.

Grown extensively since the 1960s, this versatile all-rounder is selected for its beautifully fluffy, creamy texture. It’s a great staple throughout the season as it’s fantastic for chips and mash as well as roasting.

Inca Bella

If you’re looking for a great roast potato that cooks extra quickly, try Inca Bella. This golden fleshed variety has been specially developed to roast in just 25 minutes. You can par-boil them for 5 minutes before roasting if you prefer a softer centre, but they are also great to roast from raw.


Oil or goose fat?

While the tater traditionalists wouldn’t dream of roasting their Christmas spuds in anything other than goose fat, other choices including olive oil, rapeseed oil, sunflower oil and even relative newcomers such as avocado oil can all work well instead. These can be particularly useful if you are cooking to accommodate a vegetarian or vegan coming to the dinner table.

In fact, recent scientific research using Maris Piper found that it was in fact olive oil that produced the crispiest, crunchiest and chewiest crust and most moist inner flesh.  For the fluffiest insides, it was goose fat and coconut oil that emerged as winners.


Cooking method

To determine which oil or fat produced the tastiest, crunchiest and fluffiest potatoes, researchers made their roast potatoes with the following cooking method:

Pre-heat the oven to 200c (fan) then cut potatoes into equal sized 50g chunks. Weigh out 1.5kg of potatoes and leave under cold water until required.
Place in saucepan containing one litre of cold, filtered water. Put on high heat and allow to come to boil. Once boiling, lower the heat and simmer for five minutes.
Drain using a colander the put potatoes back in the saucepan, replace the lid, then “rough them up.”
Measure two tablespoons of oil into a roasting tin and put in pre-heated oven for two minutes. If using solid coconut oil or goose fat, place in microwave before measuring.
Remove the hot oil from the oven and carefully add the potatoes to the oil. Turn the potatoes and make sure they have all been coated in the oil or fat. Place tin back in the oven and roast for 45 minutes, using a fish slice to turn the potatoes and recoat with oil/fat every 15 minutes.


Festive alternatives

Lower calorie options

For those watching their waistlines this Christmas, these low-fat cubed potatoes have all of the taste without the calories. A slight brushing of rapeseed oil adds a layer of crunch that makes roasties so popular at the dinner table without the added fat.

Red meat or game for Christmas Dinner

If you’re sitting down to a joint of beef or venison instead of the traditional turkey this Christmas, why not pack in the flavours and try this Guinness roast potato recipe.


How do you like your spuds at Christmas? Join the conversation using @seasonalspuds on Twitter or by liking us on Facebook.