What makes onions so oniony? Why does stuffing sometimes come out gummy? Learn the secret to making delicious stuffing with the perfect texture—and why onions might make you cry as you're cooking it.
Turn to Science for Great Thanksgiving Stuffing
Published: November 30, 2018
David Pogue: It's time for that delicious combination of stale bread, tasteless celery and tear-worthy onion: the stuffing!
First, you have to battle the onion.
Bridget Lancaster: You know, the way you prepare onions has a huge impact on the end result. I want you to smell this onion.
Lancaster: You can't really smell anything, right?
Pogue: It doesn't have any smell.
Pogue: Have you done something to this onion?
Lancaster: No, no, that's just a regular onion, but I'm going to show you something. So, if I just take this onion and cut it right in half, by taking the blade and slicing, I've started a chemical reaction. And now you can start to smell an aroma.
Pogue: Yes, I do.
Pogue: It smells like onions.
Pogue: The more you cut an onion, the more of that chemical reaction happens and the stronger the taste.
Inside the cell of an onion there are enzymes. These are normally kept separate from the other molecules by a barrier. When your knife cuts the onion, these chemicals come together to form new molecules. Some make you cry; others create the strong onion flavor.
So you're actually changing the flavor of a vegetable according to the mechanical action of cutting it?
Lancaster: That's right. The more you go at it and more you release those cell walls, the more flavor and the more pungent aroma is going to come out.
Pogue: One of the new molecules is propanethial-S-oxide, a volatile molecule that floats up and can trigger the tears.
Assuming you survive onion cutting, it's time to move on to the rest of the stuffing.
Bridget, you appear to be the maker of the croutons. So this is how you make real stuffing?
Lancaster: That's how you make real stuffing.
Pogue: I thought it comes in a box, you know?
Lancaster: Only if you're desperate. The key to great stuffing is getting the moisture out of bread.
Pogue: Unlike the bird itself, where the big challenge was keeping the water in, stuffing presents the opposite dilemma: getting the water out.
If you fail, you get this: mushy, gummy stuffing.
I hate gummy stuffing.
Lancaster: That was one of the Pilgrims' top 10 most hated things.
Pogue: Most recipes call for using stale bread, but, at Cooks, they have discovered a problem with that. In stale bread, the water actually gets trapped inside the crystal structure of the starch granule. So while the bread may feel dry, it actually has lost very little of its water.
Lancaster: So, if you were to reheat this, you know wrap it in foil, you could actually bring back this baguette and it would be really nice and moist and you could eat it. But for a stuffing it is still going to be too moist. That's going to make the stuffing gummy.
Pogue: So how do you avoid the gummy curse?
Lancaster: So you want to cut the bread into cubes, and then we dry these on a really low oven, about 250 degrees, and that's perfect because it's going to basically dehydrate the bread.
Pogue: So now, inside the starch granule there is much less water.
Lancaster: So, you can see it's still moist, but the cubes are not turning to paste.
Pogue: Thanksgiving saved.
Written, Directed, and Produced by: Doug Hamilton
Hosted by: David Pogue
Digital Producers: Sukee Bennett and Olivia Schmidt
© WGBH Educational Foundation 2018