The Nature of Things

Q & A: Four years and 20,000 potatoes later, this man has a PhD in mashed potatoes

Culinary scientist Ali Bouzari set out to prove ‘beyond a reasonable doubt, the exact mechanism by which potatoes got tasty.’

Culinary scientist Ali Bouzari researched how to make mashed potatoes with the best texture — every time.

Culinary scientist Ali Bouzari spent four years perfecting mashed potatoes for his PhD. "I wanted to learn: what is it that makes potatoes creamy? What is creaminess? How does that change with the amount of water you cook potatoes in? The amount of fat? The amount of salt, does salt matter?" (CBC/Chef Secrets: The Science of Cooking)

Turns out there's more to mashed potatoes than just smashing them and adding some butter — much, much more. 

As a PhD student, culinary scientist Ali Bouzari set out to find the best possible texture of mashed potatoes (he likes them really smooth and creamy). He spent almost four years working in a lab to create — and replicate — the most delicious mashed potatoes. 

For Bouzari, that meant lots and lots of analyzing the structure, components and process of making mashed potatoes. 

Read on to learn more about Bouzari's mashed potato journey. But if you only have a minute, here are his top three tips for perfect mashed potatoes:

  • leave the skins on when you boil them

  • use a tamis, sieve or a food mill to mash them

  • add a comical amount of butter 

Bouzari appears in the documentary Chef's Secrets: The Science of Cooking, which explores how understanding science can make you a better cook. 

Q: Why mashed potatoes? 

A: I don't think there's anybody who doesn't like mashed potatoes, they're delicious. I don't know that I, like, grew up with a poster on my wall of a potato, but what I really liked about it is that it was something that felt fundamental and fairly universal: mashed root vegetable is found everywhere.

[When I got to grad school] I really wanted to find a project that was food focused, not just food science, not just "one trace molecule in a watermelon and how it evolves over the course of X, Y or Z."

I wanted to learn something about cooking and study something about cooking.

I actually had a very brief conversation with Harold McGee in the hallway at one point (editor's note: McGee is an American author who writes about the chemistry and history of food science and cooking. He is best known for his book On Food and Cooking: The Science and Lore of the Kitchen). 

I said, "Hey, if you were in grad school, in theory, and you were looking for a thing to study, what would you do?"

He said, "Potatoes are interesting."

And we talked a little bit about the types of potatoes and what makes their texture happen. 

Then, I was fortunate enough to [speak] with a bunch of chefs at the French Laundry (editor's note: a famous 3-Michelin star French restaurant in the Napa Valley in California), where they've been known to make really good potatoes. [They had] some questions...about potato puree [and] mashed potatoes: why would they get gluey or why would they get floury or why would they get mealy, [at] different times? 

So I made mashed potatoes for four years and then got a certificate for it.

I did not get sick of mashed potatoes after four years- Ali Bouzari

Q: What were you trying to figure out about potatoes?

A: I was interested in how to make the most delicious mashed potatoes. As much as something as subjective as food can have an objective truth, I wanted the best possible texture of mashed potatoes. 

We got there in about six weeks. The remaining three-and-a-quarter years were proving, beyond a reasonable doubt, the exact mechanism by which potatoes got tasty (I did not get sick of mashed potatoes after four years).

WATCH: Ali Bouzari explains the science behind perfect mashed potatoes. 

After 4 years and 20,000 Yukon Golds, this man has a PhD in mashed potatoes | Chef Secrets: The Science of Cooking

16 days ago
Duration 4:37
Culinary consultant Ali Bouzari mapped out how the tissue of a potato shifts and changes during cooking in order to find the best possible texture for mashed potatoes. 4:37

Q: Was there a certain thing, a tendency, in mashed potatoes that you were trying to work around?

A:  Anybody who's ever had a family member who's prone to fooling around with food too've had mashed potatoes that cement your mouth shut. There's some stuff that happens where, if starch is beaten up and abused a little bit too much, it starts to get webby. It starts to Spider-Man itself together and that can cause stickiness. 

I wanted to learn: where does sticky come from in potatoes? I wanted to learn: what is it that makes potatoes creamy? What is creaminess? How does that change with the amount of water you cook potatoes in? The amount of fat? The amount of salt, does salt matter?' 

I wanted to know: the duration of how long you cook potatoes, does that matter for how the texture changes? What do enzymes in the potato do? What does the cell wall versus the starch granule do? 

Basically, I wanted to map out: how does the tissue of a potato shift and change during cooking and how does that give you awesome  or not so awesome — mashed potatoes.

Q: So after all those years of work, how do you make perfect mashed potatoes?

Boil the potatoes with the skin on; skip the hand masher and use a tamis, a food mill with a little crank or a mesh pasta strainer; and add a comical amount of butter.

Say goodbye to the hand masher for smooth, creamy mashed potatoes. A tamis or food mill is the key to Ali Bouzari's perfect mashed potatoes. (CBC/Chef Secrets: The Science of Cooking)

Q:  Most people probably think it's easy to make mashed potatoes: throw in potatoes, a pot of boiling water, mash them up, add butter and voila! Is that fact or myth?

A: Confirmed fact. Even after everything I learned, it is still easy to make mashed potatoes.

That's another cool thing about mashed potatoes: they're going to be good. Even when they're bad, they're totally fine. 

And I don't think that anybody ever needs to see the way that I studied the way to make mashed potatoes as the only way, but to take something-- let's say your average mashed potato, that you made just add, boil some potatoes, mash it with a fork and then add in some butter and salt. Let's say that's 70 per cent "perfect." 

The last 30 per cent takes some doing. 

I would say that the... the last 15 per cent is real hard. 

So most of the things that I look at, boiling the potatoes with the skin on; pureeing them while they're still warm; adding butter with a spatula instead of like an electric whisk — that will probably get you to 85 per cent perfect. 

85 per cent perfect mashed potatoes are still, like, the best potatoes you've ever had.

Q: What was the most surprising thing you learned when you were doing all this research?

A lot of the old-school French methods for making mashed potatoes were spot on. There were just a lot of things that people were doing...almost a century ago that were exactly right, scientifically.

I think that's one of the really cool things about the science of cooking. We're not inventing any of this, we're just discovering, "Oh, that's exactly how that works."

Nobody, none of our grandparents needed our permission or our scientific blessing to do whatever they were going to do. 

They figured it out through trial and error. 

Clearly people were making great mashed potatoes before I did a PhD in mashed potatoes. Now...we understand a little bit of exactly what's going on.

Today, Bouzari runs Pilot R&D, a culinary research and development company. He's the author of Ingredient: Unveiling the Essential Elements of Food.

The documentary Chef's Secrets: The Science of Cooking from The Nature of Things explores how understanding science can make you a better cook. 

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