How to Choose Potatoes

Potatoes are the backbone of the Irish kitchen, and choosing the right one can make the difference between a light, fluffy mash and a gluey one. Yet most of us pick up whatever bag is nearest without thinking about it. This guide explains the difference between the main types in plain language, so you can choose with confidence.

Floury versus waxy

Potatoes are broadly divided into two types: floury and waxy. The difference comes down to how much starch they contain and how much moisture they hold.

Floury potatoes are high in starch and low in moisture. When cooked, they break down easily and become light and fluffy. This makes them ideal for mashing, baking and roasting, where you want a soft, absorbent texture. Common floury varieties include Maris Piper, Rooster and King Edward.

Waxy potatoes are lower in starch and higher in moisture. They hold their shape well when cooked, which makes them perfect for boiling, salads and dishes where you want the potato to stay intact. Common waxy varieties include Charlotte, Nicola and new potatoes.

Which potato for which job

Here is a simple guide to matching the potato to the dish:

• Mashing: use a floury potato. It breaks down easily and gives the lightest, creamiest result. This is the key to a good colcannon.
• Roasting: a floury potato roasts the crispiest, because it dries out on the outside while staying fluffy within.
• Boiling: a waxy potato holds its shape and stays firm, which is what you want for boiled potatoes and salads.
• Stews and casseroles: a floury potato will break down and thicken the broth, which is often desirable in a stew. If you want the potatoes to stay whole, use a waxy variety.
• Frying and chips: a floury potato gives a fluffy interior and crisp exterior, which is why it is the classic choice for chips.

How to tell them apart

If the bag does not tell you the variety, there are a few clues. Floury potatoes tend to have a rougher, more textured skin and a paler flesh. Waxy potatoes are often smoother-skinned and firmer to the touch. New potatoes, which are harvested early, are almost always waxy.

When in doubt, ask at the shop or market. Most greengrocers are happy to tell you which potatoes are best for mashing and which are best for boiling.

Storing potatoes

Potatoes keep best in a cool, dark, dry place, such as a cupboard or a paper bag. Avoid storing them in the fridge, where the cold turns their starch into sugar and makes them taste sweet and discolour when cooked. Keep them away from onions, which can cause them to sprout more quickly.

Discard any potatoes that have turned green or sprouted heavily, as they can contain higher levels of a natural compound that is not good to eat in large amounts.

Putting it into practice

Now that you know the basics, try it in the kitchen. Our colcannon and boxty recipes both rely on choosing the right potato, and our Irish stew shows how a floury potato can enrich a broth. Cooking with the right potato is one of the simplest ways to improve your results.