Hello lovelies,
there are very few ingredients in my kitchen where so much can go wrong for so little reason, and with potatoes it is almost never the recipe's fault. If the potato salad turns to mush, the potato was wrong. If the mash goes gluey, the potato was wrong. And if the roast potatoes taste oddly sweet and darken far too fast, that usually comes down to where the potatoes were sitting beforehand.
Back in Switzerland we had a cool cellar where a sack of potatoes happily lasted two months. In Bali there is no cellar and it is 30 °C (85 °F) outside, so I had to learn the whole thing again from scratch. What came out of it is reassuringly simple: there are two questions, and both hang on the same thing.
The first is which potato you buy. The second is where you put it. Both answers come back to the starch inside the tuber. That is what this is about.
Which potatoes should you use for what?
Starch decides everything: the more starch a potato holds, the fluffier and drier it cooks, and the more readily it falls apart. That is why potatoes get sorted into three groups, and why it is worth knowing which one is in your hand.
Waxy potatoes hold the least starch. They stay firm after cooking, keep their skins intact and slice cleanly. Red potatoes, fingerlings and new potatoes live here. Starchy potatoes hold the most: Russets are the obvious example, and they turn dry and fluffy and break down readily. In between sit the all-purpose potatoes, with Yukon Gold as the classic.
This sounds like trivia until it isn't. You will never get a good potato salad out of a Russet, because it dissolves in the dressing. And you will never get light, fluffy mash out of a red potato, because it simply refuses to give up its structure.
| Type | Starch | How it cooks | Best for | Common varieties |
|---|---|---|---|---|
| Waxy | lowest | holds its shape, skin stays intact | potato salad, roasting, gratins, boiling whole | red potatoes, fingerlings, new potatoes |
| All-purpose | medium | crisp outside, soft inside, skin may split | oven dishes, stews, curries, everyday boiling | Yukon Gold |
| Starchy | highest | falls apart, turns dry and fluffy | mash, soup, dumplings, gnocchi dough | Russet, Idaho |
Once that logic clicks, you shop differently. It is the same thinking as with apples, where not every variety belongs in every pie, and we wrote about picking the right baking apple separately.
How can you tell if a potato is waxy or starchy?
By the variety name, because you cannot see starch content in a raw potato. In the US most stores label by variety rather than by cooking type, so the variety is your shortcut: Russet means starchy, Yukon Gold means all-purpose, red or new means waxy.
At a farmers market, just ask. Growers almost always know exactly which variety they are selling and are happy to say so, and they often have varieties the supermarket never carries.
One thing that surprises people: new potatoes are effectively always waxy. Starch develops during storage, so freshly dug tubers simply have not built much of it yet. If you are trying to make mash in early summer and it refuses to go fluffy, that is not your technique.
For any dish where the potato has to stay a recognisable piece of potato, reach for waxy or all-purpose. An Indian potato and cauliflower curry, for instance, needs cubes that are still cubes after twenty minutes in the pan, not a cloudy sauce with a rumour of potato in it.
What should you look for when buying them?
New potatoes arrive in early summer; the storage varieties come in from late summer into fall. That is exactly why autumn is the season when buying a real quantity makes sense: late-season potatoes are bred to keep for months, which is how they stay on the shelves all winter.
New potatoes have thin, delicate skins and little starch. They taste lovely and they are not for storing, so plan on eating them within a few days. Late-season potatoes have tougher skins and more starch, and those are the ones worth buying in bulk in September.
At the store I check three things, and it takes about ten seconds. The potato has to be firm and not give when I press it. It cannot have green patches, not even small ones. And it cannot be shrivelled or already sprouting. Extension guidance says the same: pass on potatoes with large cuts, cracks, bruises, decay, sprouting eyes or shrivelling. One bad tuber will take the rest of the bag with it.
Loose potatoes you can actually see beat a sealed plastic bag almost every time. Moisture collects in the bag, and you only ever see the top layer.
How should you store potatoes?
Cool, dry, dark and well ventilated, ideally around 7 to 10 °C (45 to 50 °F). Stored that way they keep for weeks. Each part of that sentence is doing work.
Dark, because light turns the skin green. Cool, because warmth makes them sprout and lose moisture. Dry and ventilated, because trapped condensation invites rot. So take potatoes out of the plastic bag, or at least open it, and keep them in a paper bag, an open crate or a basket. A cupboard away from the stove and the dishwasher beats a countertop in the light.
A cellar or an unheated pantry is still the ideal. If you do not have one, use the coolest dark corner you have and buy smaller amounts more often. In a normally warm kitchen you are looking at a week or two before they start sprouting.
The thing most people miss is that appliances give off heat. The cupboard right beside the oven, above the dishwasher or behind the refrigerator runs noticeably warmer than the rest of the kitchen, and that is where potatoes sprout fastest. Pick the spot furthest from anything that produces heat.
In Bali that spot simply does not exist for us. So I never buy more than about two pounds at a time and I plan on eating them within the week. It is not an elegant solution, but it is an honest one: nothing outsmarts a 30 °C (85 °F) kitchen except buying less at once.
Not every vegetable wants the same treatment, either. Which ones we keep in the fridge and which ones we deliberately don't is in our post on which vegetables belong in the fridge.
| Question | Answer |
|---|---|
| Where | cool, dry, dark and well ventilated |
| Ideal temperature | around 7 to 10 °C (45 to 50 °F) |
| How long | about a month at best quality, longer in a proper cellar |
| Refrigerator | no, cold turns starch into sugar |
| Packaging | take them out of the plastic bag, use paper or an open crate |
| Green spots and sprouts | trim them away generously |
| Bitter taste | do not eat the dish |
Why shouldn't you refrigerate potatoes?
Because cold converts the starch into sugar. The potato tastes faintly sweet afterwards, and it browns far too quickly when you fry or roast it.
This is not kitchen folklore. One study compared three common potato varieties stored at 4 °C (39 °F) against the same varieties stored at 8 °C (46 °F). The colder ones had built up substantially more reducing sugars, and frying them produced measurably more acrylamide. The encouraging part: the process is reversible. Let a cold-stored potato sit somewhere warmer for a few days and some of that sugar converts back.
In practice, that means raw potatoes never go in our fridge. Cooked ones absolutely do. They keep for a few days and they make the best roast potatoes you will ever get out of a pan.
Are green potatoes and sprouts safe?
Green means too much light. Chlorophyll builds up under the skin, and alongside it the tuber accumulates glycoalkaloids, of which solanine is the best known.
Michigan State University Extension recommends a clear approach: store potatoes cool, dark, dry and well ventilated; avoid buying green, shrivelled or sprouted tubers in the first place; trim away any small green spots, sprouts and eyes before cooking; and discard green-skinned and sprouted potatoes rather than trying to rescue them. If a finished potato dish tastes bitter, it does not belong on the plate.
Small sprouts on an otherwise firm potato are not a crisis. I cut them off and carry on. A shrivelled potato that is already half sprout goes in the compost. That is the one place I am not thrifty.
Extension guidance is stricter for young children: do not give them green potatoes, trimmed or not. In our house the potatoes for the kids' plates get peeled as a matter of course.
How long do potatoes last, and what do you do with old ones?
About a month at best quality in good conditions, and a week or two in a normally warm kitchen. Late-season potatoes are bred and harvested for storage, which is why they are on the shelves all winter.
The useful thing is that potatoes do not turn bad suddenly. They soften, then wrinkle, then sprout. The moment I notice a bag heading that way, I cook the whole lot at once. Soup, mash and bakes forgive a slightly older potato far more readily than a salad does.
That is exactly what starchy potatoes are for. Baked gnocchi with spinach is our recipe for making a large leftover quantity disappear in one go, and soup gets frozen in portions. How to do that without wrecking the texture is in our post on freezing potato soup properly.
Three dishes that need you to pick the right type:
Do you need to peel potatoes?
Not always, but it depends on the condition of the tuber. A lot of the nutrients sit just under the skin, so there is a good case for leaving it on. That case only holds for clean, fresh potatoes with no green patches and no damage.
With new potatoes, a scrub under running water is plenty. With older ones out of storage I peel, because glycoalkaloids concentrate in and just under the skin and you cannot tell by looking how long a potato spent in the light.
Frequently asked questions
Can you store potatoes in the refrigerator?
Better not. In the cold a potato converts starch into sugar, which makes it taste faintly sweet and brown too quickly when fried or roasted. One study found substantially more reducing sugars and more acrylamide on frying at around 4 °C (39 °F) storage than at 8 °C (46 °F). Cooked potatoes, on the other hand, belong in the fridge.
Are green potatoes safe to eat?
Michigan State Extension recommends trimming away small green spots, sprouts and eyes, and discarding green-skinned or sprouted potatoes rather than salvaging them. If a cooked potato dish tastes bitter, do not eat it. Green potatoes should not be given to small children at all, trimmed or otherwise.
Which potatoes are best for mashed potatoes?
Starchy ones, Russets above all. They hold the most starch, break down as they cook and mash up light and fluffy. Waxy potatoes stay too firm and turn gluey rather than airy when you work them.
How long do potatoes last?
Kept cool, dark, dry and ventilated, roughly a month at best quality, and longer in a genuine cellar. In a normally warm kitchen plan on a week or two, and buy smaller amounts more often.
Why are new potatoes always waxy?
Because starch develops during storage. Freshly dug tubers have not built much of it yet, so they stay firm regardless of variety. For properly fluffy mash you want late-season, stored potatoes.
In the end it really is just those two things: buy the right potato, and put it in the right place. Neither costs anything, and between them they rescue a surprising number of dinners. If you are reorganising your pantry anyway, it is worth a look at storing cucumbers the right way, where almost the opposite rules apply.
Now I am curious: do you have somewhere cool for potatoes, or is the kitchen the only option where you are?
Yours, Verena
Sources
- 1.University of Arkansas Cooperative Extension Service · Knowing the Types of Potato to Use in Your Cooking
- 2.Michigan State University Extension · Are green potatoes safe to eat? · 2024
- 3.Journal of Agricultural and Food Chemistry (via PubMed) · Influence of storage practices on acrylamide formation during potato frying · 2005
