I thought I already knew how to make good roasted potatoes.
Cut them into chunks. Boil them for a few minutes. Drain them. Add oil and seasoning. Roast until golden brown.
Simple, right?
Then I came across a technique that sounded almost too strange to be useful:
Add baking soda to the water when boiling the potatoes before roasting them.
At first, I wasn’t convinced.
Baking soda is something I normally associate with baking, cleaning, and occasionally rescuing an overly acidic recipe. I certainly didn’t think of it as something that belonged in a pot of potatoes.
But the idea behind the technique is surprisingly clever.
So I tried it.
I cut the potatoes into chunks, brought a pot of water to a boil, added salt and a small amount of baking soda, and dropped the potatoes in.
After boiling, I drained them and gave them a good shake in the pot.
Then I tossed them with oil and seasoning and put them into a hot oven.
Forty-five minutes later, I understood why people swear by this trick.
The outside of the potatoes had become dramatically rougher and more textured than my usual boiled potatoes.
And those rough edges?
They turned into incredibly crisp, deeply browned surfaces in the oven.
The inside remained fluffy and tender.
It was one of those small cooking tricks that made a surprisingly noticeable difference.
Here’s what was actually happening.
Why Would Anyone Put Baking Soda in Potato Water?
The secret isn’t that baking soda somehow “flavors” the potatoes.
It doesn’t.
The important thing is what baking soda does to the water’s alkalinity.
Baking soda, also known as sodium bicarbonate, makes the cooking water more alkaline.
That higher-pH environment affects the surface of the potatoes as they boil.
The outer layer becomes softer and more prone to breaking down.
That may sound like a bad thing.
But for roasted potatoes, it’s exactly what we want.
A rough, starchy exterior provides more surface area for oil and heat to work on.
Instead of having a smooth potato surface, you end up with lots of tiny ridges, flakes, and rough patches.
Those irregular surfaces can become beautifully crisp during roasting.
The First Surprise Happened Before the Potatoes Even Went Into the Oven
After boiling the potatoes, I drained them.
Normally, boiled potatoes look fairly smooth.
These didn’t.
The surfaces looked noticeably rough.
Some edges had begun to break apart.
There were little starchy bits clinging to the outside.
At first glance, they looked almost overcooked.
But that was actually the point.
I tossed them around in the pot for a few seconds.
That made the surface even rougher.
Instead of worrying about the potatoes falling apart, I realized I was creating exactly the texture I wanted for roasting.
The rougher the exterior became, the more opportunities there would be for browning.
Shaking the Pot Is More Important Than It Sounds
This was one of the most important steps.
After draining the potatoes, I didn’t immediately transfer them to the roasting pan.
I put the lid back on the pot and gently shook the potatoes.
The goal wasn’t to pulverize them.
I simply wanted to knock the edges around enough to create a thin layer of mashed-up potato starch on the exterior.
This coating might look messy at first.
But in the oven, it becomes part of the crust.
Think of it almost like creating a naturally rough coating without using breadcrumbs.
The potato itself provides the starch.
Then Came the Oil
Once the potatoes were roughed up, I added oil.
And this is where the rough surface really started making sense.
Oil can cling to all those irregular little ridges and crevices.
A perfectly smooth potato surface doesn’t have nearly as much texture for oil to coat.
But a rough potato has dozens of tiny edges.
When those edges hit a hot roasting pan, they begin to brown.
The result is a much more complex crust.
You get crisp edges.
Crunchy corners.
Golden ridges.
And a fluffy center underneath.
Forty-Five Minutes Later, the Difference Was Obvious
After roasting, the potatoes looked completely different from the ones I normally make.
The outside was deeply golden.
Some edges were almost craggy.
There were little crunchy pieces sticking out from the surface.
When I pressed a fork against the exterior, it resisted before cracking through.
Then the fork reached the center.
Soft.
Fluffy.
Steamy.
That contrast was the entire reason the technique worked.
Crunchy outside. Fluffy inside.
That’s what most people want from a roasted potato.
And baking soda helped make that contrast easier to achieve.
The Inside Didn’t Become Mushy
One concern I had before trying the technique was that the potatoes would become too soft.
After all, if baking soda causes the outside to break down faster, wouldn’t the whole potato eventually turn mushy?
Not if you control the boiling time.
The idea isn’t to completely cook the potatoes until they fall apart.
You’re partially cooking them and deliberately roughening the exterior.
The interior should remain intact enough to hold its shape when transferred to the roasting pan.
That’s why potato size matters.
Large chunks can handle a little more cooking.
Small pieces cook much faster and can fall apart.
If you cut your potatoes too small, you may end up with mashed potato fragments instead of roast potatoes.
The Baking Soda Doesn’t Need to Be Added Generously
This is one of the biggest mistakes you can make with the technique.
More baking soda does not automatically mean better potatoes.
You only need a small amount.
Too much can make the cooking water excessively alkaline and potentially give the potatoes an unpleasant taste or affect their texture too aggressively.
A commonly used approach is roughly ½ teaspoon of baking soda per liter (about 4 cups) of boiling water, although exact amounts can vary depending on the quantity of potatoes and the cooking method.
The goal is subtle.
You’re changing the cooking environment, not turning the potato water into a science experiment.
Don’t Skip the Salt
Baking soda isn’t a replacement for salt.
Salt and baking soda serve different purposes.
Salt seasons the potatoes.
Baking soda changes the alkalinity of the water and helps affect the surface texture.
So if you want flavorful potatoes, season the boiling water with salt as you normally would.
This is one of those cases where the basic technique remains important even when you’re adding a clever extra step.
Why the Potatoes Brown So Well
There are actually several things happening during roasting.
The potatoes contain starches and sugars.
The oil helps transfer heat to the surface.
The hot oven drives off moisture from the exterior.
As the surface becomes drier and hotter, browning reactions accelerate.
The roughened surface created during boiling gives those reactions much more territory to work with.
The result is a deeply browned crust with lots of tiny crisp surfaces.
This is one reason simply roasting raw potatoes doesn’t always produce the same texture.
Raw potatoes begin with a relatively smooth surface.
Parboiling changes that surface.
Baking soda can exaggerate that effect.
The Type of Potato Matters
Not every potato behaves exactly the same way.
For especially fluffy interiors and crisp exteriors, many cooks like using potatoes that are relatively high in starch.
Russet potatoes are an obvious choice.
Some waxier potatoes can also produce excellent roasted results, particularly when you prefer a creamier interior.
The important thing is understanding what you’re aiming for.
If you want a very fluffy center surrounded by a rugged crust, a starchier potato is an excellent candidate.
If you want a firmer, creamier center, another variety may be preferable.
Should You Peel the Potatoes?
That’s completely up to you.
I actually like leaving the skin on when the potatoes are clean and suitable for eating.
The skin adds another layer of texture.
It can become crisp around the edges while the interior remains soft.
If you prefer peeled roasted potatoes, the baking soda technique still works.
The important part is the starchy exterior underneath the skin.
What Happens If You Skip the Shaking Step?
You can still roast the potatoes.
But you may not get the same dramatic crust.
The shaking step is what turns the already-softened potato surface into a rough, starchy coating.
Without that roughness, the potato remains smoother.
A smoother surface generally means fewer crispy ridges and less texture.
So don’t be afraid of making the potatoes look slightly messy before roasting.
That messiness is exactly what you want.
The Roasting Pan Needs to Be Hot
Another major lesson from the experiment is that the oven and roasting surface matter.
If you put cold potatoes onto a cold pan and place everything into the oven, the potatoes spend more time warming up before serious browning begins.
A hot roasting pan can give the potatoes a much stronger start.
When the oiled potatoes hit the hot surface, moisture begins evaporating and browning can begin more efficiently.
Just be careful when handling a preheated pan.
Use proper oven mitts and avoid splashing oil.
Don’t Crowd the Potatoes
This is one of the easiest ways to ruin an otherwise excellent batch.
If the potatoes are packed tightly together, they release steam.
Instead of roasting and crisping, they can begin steaming each other.
Give each piece some breathing room.
A single layer with space between the potatoes is ideal.
If you’re making a large quantity, use two roasting pans rather than piling everything onto one.
More surface area means more opportunities for crisping.
Oil Makes a Big Difference
You don’t need to drown the potatoes in oil.
But you do need enough to coat the roughened surfaces.
Olive oil works beautifully.
Neutral oils can also work.
The choice depends on your preferred flavor and cooking temperature.
Toss the potatoes thoroughly so that the oil reaches the rough edges.
Those edges are where the magic happens.
What Seasonings Work Best?
Once you’ve got the texture right, the seasoning possibilities are almost endless.
Classic roasted potatoes work beautifully with:
- Salt
- Black pepper
- Garlic powder
- Onion powder
- Rosemary
- Thyme
- Paprika
- Parsley
You can also experiment with smoked paprika, chili flakes, Parmesan, or other herbs and spices.
One thing I’d recommend is adding delicate fresh herbs toward the end of cooking rather than exposing them to intense heat for the entire roasting period.
Fresh garlic can also burn if placed on the potatoes too early.
Can You Add Parmesan?
Absolutely.
Parmesan can create an additional savory crust.
But because cheese can brown quickly, consider adding it toward the latter part of roasting rather than at the very beginning.
The same principle applies to many toppings.
The potato needs time to crisp first.
Then you can add ingredients that brown more rapidly.
Why the Technique Became So Popular
The baking soda trick became popular because it solves a very specific roasted-potato problem.
People want potatoes that are:
Crispy on the outside.
Fluffy on the inside.
Getting both qualities at the same time can be tricky.
If you roast potatoes without parboiling, the outside may brown before the inside becomes perfectly tender.
If you boil them too much, they can become too soft.
If you don’t roughen the surface, you may not get enough crust.
Baking soda helps create a rougher exterior during parboiling.
It’s not magic.
It’s a small chemical adjustment that changes the texture you’re able to create.
What If You Add Too Much Baking Soda?
This is where the experiment can go wrong.
Too much baking soda can make the potatoes taste unpleasant or soapy.
It can also cause the surface to break down excessively.
Instead of beautifully rough potatoes, you may end up with pieces that are difficult to handle.
So resist the temptation to think:
“If a little is good, more must be better.”
That’s not how this technique works.
Use a modest amount.
Can You Use Baking Powder Instead?
Not really.
Baking powder and baking soda aren’t interchangeable here.
Baking soda is sodium bicarbonate and directly raises the alkalinity of the cooking water.
Baking powder contains baking soda plus acidic ingredients and starches.
The goal of this potato technique is specifically to make the water more alkaline.
So if you’re trying this method, use baking soda rather than substituting baking powder.
Does Baking Soda Make Potatoes Healthier?
Not particularly.
This technique is primarily about texture, not nutrition.
The potatoes are still potatoes.
You’re simply changing how the surface behaves during cooking.
The nutritional value of the final dish will depend much more on the potatoes themselves, how much oil you use, and what else you add.
Think of baking soda as a culinary tool, not a health ingredient.
My Biggest Mistakes During the Experiment
The first time I tried it, I made a few mistakes.
I cut some pieces too small.
Those pieces became softer than I wanted.
I also didn’t leave enough space between the potatoes on the roasting tray.
That meant some areas steamed instead of crisping.
And I initially underestimated how quickly the rough edges could brown.
Once those edges became golden, they needed close attention.
The next batch was much better.
Larger chunks.
More space.
Better oil coverage.
And careful monitoring during roasting.
A Simple Method to Try at Home
If you want to experiment with the technique, here’s the basic approach.
Start by cutting your potatoes into evenly sized chunks.
Bring a pot of salted water to a boil.
Add a small amount of baking soda.
Carefully add the potatoes.
Boil until the outside is tender but the potatoes are still firm enough to hold their shape.
Drain them thoroughly.
Let excess moisture evaporate briefly.
Return the potatoes to the pot.
Shake them gently to rough up the surfaces.
Toss them with oil and your preferred seasonings.
Spread them in a single layer on a roasting tray.
Roast in a hot oven until deeply golden and crisp, turning as needed.
The exact cooking time will depend on the size of the potatoes and the temperature of your oven.
Frequently Asked Questions
Does baking soda really make roasted potatoes crispier?
It can. The alkaline cooking water encourages the potato’s exterior to break down and become rougher. That rough surface provides more area for browning and crisping during roasting.
How much baking soda should I use?
A small amount is sufficient. Around ½ teaspoon per liter (about 4 cups) of water is a reasonable starting point. Avoid adding large amounts because too much can affect flavor and texture.
Do I have to boil the potatoes first?
No, but parboiling helps create the fluffy interior and rough exterior that make this particular method effective.
Can I use baking soda with peeled potatoes?
Yes. The technique works with both peeled and unpeeled potatoes.
Why do I shake the potatoes after boiling?
Shaking roughens the softened surface and creates a starchy coating. That rough coating becomes extremely crisp during roasting.
Can I use olive oil?
Yes. Olive oil is a popular choice, although other cooking oils can also work.
Why are my potatoes falling apart?
They were probably boiled too long, cut too small, or handled too aggressively. Reduce the boiling time and shake them gently.
Why aren’t my potatoes crispy?
Possible causes include overcrowding the pan, insufficient oil, low oven temperature, too much surface moisture, or not roughening the potatoes enough before roasting.
The Final Result
Forty-five minutes after I started the process, I had a tray of potatoes that looked completely different from my usual roasties.
The outsides were rugged and deeply golden.
The edges were crunchy.
The centers were soft and fluffy.
And those little rough patches created by the baking soda and vigorous shaking had become some of the best parts of the entire dish.
The most important thing I learned was that the baking soda isn’t there to make the potatoes taste like baking soda.
It’s there to change the surface.
That tiny adjustment to the boiling water helps create a rough, starchy exterior that is almost perfectly designed for roasting.
So if your roasted potatoes usually come out golden but not truly crispy, this is a technique worth trying.
Just remember the basic rules:
Use only a small amount of baking soda.
Don’t over-boil the potatoes.
Shake them enough to roughen the surfaces.
Don’t overcrowd the roasting pan.
Use enough oil to coat the rough edges.
And roast them hot enough to develop that deep golden crust.
Sometimes the biggest improvement to a familiar recipe doesn’t require a completely new ingredient list.
It only requires understanding what one tiny ingredient is doing.
In this case, a little baking soda turned an ordinary pot of potatoes into the beginning of something much crispier.
Forty-five minutes later, I wasn’t looking at ordinary roasted potatoes anymore. I was looking at potatoes with the kind of crunchy, craggy crust I’d been trying to achieve all along.