Chef Jack Bishop Breaks Down ‘The Science of Good Cooking’

In an interview from 2012, Jack Bishop from America’s Test Kitchen explains how science can sharpen your cooking skills.

Speaker names marked ? are inferred from speaking time and the show’s known hosts — they are not voice-verified.

• 0:00Speaker 00

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• 1:20Speaker 03

  I just can't believe that Thanksgiving's already next week, and I could really use some tips for making my pie dough just a little bit flakier.

• 1:27Speaker 04

  When the water is mixed with the flour, you are activating the glutens, which is great if you're making bread, but in pie dough, it will make it fairly tough. And it turns out that alcohol does not form gluten when it's mixed with flour.

• 1:40Speaker 03

  I'm listening. It's Thursday, November 21st. It's one week until Turkey Day, and this is Science Friday.

• 1:51Speaker 03

  I'm John Dankoski. It's been our custom on this show to bring science to the table and the kitchen and offer you some helpful suggestions based on cooking chemistry. Well, back in 2012, Ira Flatow sat down with Jack Bishop from America's Test Kitchen. They had just released their book, The Science of Good Cooking. Have a listen.

• 2:09Ira Flatow?

  We're cooking in on New York studio. Welcome to Science Friday, Jack.

• 2:12Speaker 04

  Hi, Ira. Great to be here.

• 2:13Ira Flatow?

  We are surrounded by cooking stuff.

• 2:16Speaker 04

  I know. We don't really, you know, the wires and all the radio things with cooking things. Let's hope it goes well.

• 2:21Ira Flatow?

  Well, let's get right to the first thing. We have a pot of, a simmering pot of water here. Well, it's not actually a pot, is it?

• 2:26Speaker 04

  It's a skillet. So I am going to reteach you how to poach an egg, and you're going to be successful.

• 2:32Ira Flatow?

  In a skillet? I've never done it in a skillet. Usually you take the big pot of water. That's wrong, you're saying.

• 2:37Speaker 04

  The big problem with the saucepan, if you're doing a narrow pot, it's a long way down for the egg to drop into the pot. A lot of people crack it right on the side of the saucepan, and then it falls apart. I mean, the challenge when you're poaching an egg is to keep the white to surround the yolk. So you end up with a set white and a creamy yolk.

• 2:55Ira Flatow?

  All right.

• 2:55Speaker 04

  The skillet makes it much easier. So I've got boiling water in a 12-inch skillet. You can use a smaller skillet if you'd like. And the trick here is we're going to gently coax the eggs in. So I've got two teacups, one in each hand. They have little handles on them to allow me to get close to the water. And I've got two eggs cracked in each. And I'm just going to turn them ever so gently into the skillet. I'm going to add a little bit of vinegar. The pH is going to help.

• 3:26Ira Flatow?

  Ah, the acidity is going to help.

• 3:29Speaker 04

  And a little salt, really, just for flavor. And I'm going to turn off the heat. The other big mistake people make is they boil, and the turbulent water will cause the eggs to break apart.

• 3:40Ira Flatow?

  So you don't want to boil it.

• 3:41Speaker 04

  And I can turn my timer on. And so by using residual heat, you are sort of, no churning of the water, so you're not going to blow apart the eggs. And you also get a really consistent result. Because, you know, if you've got a really powerful cooktop, it can be going much sort of faster, coming back to the boil. And we're basically just doing it with residual heat. If you were doing it on a real cooktop, we're on a little induction burner, you might even slide it off the burner onto a cool burner. We don't have a cool burner, so we're going to hope this induction burner cools down.

• 4:11Ira Flatow?

  And the vinegar helps coagulate the egg whites? Is that, the acid does that?

• 4:15Speaker 04

  Yes. We're lowering the pH of the water. And that helps the proteins in the white to sort of unfurl more quickly and bond together and hopefully protect the creamy yolk.

• 4:29Ira Flatow?

  Could you use lemon juice instead?

• 4:31Speaker 04

  You could use lemon juice. I just use distilled white vinegar. You don't want to use a colored vinegar like balsamic would give you lightly tinged whites, which may not be that attractive. But you know, the vinegar will give a little bit of flavor to the eggs, balance a little of the richness of the eggs, which is a good thing. So we like that.

• 4:50Ira Flatow?

  Well, while we're waiting for the eggs to cook, let's talk a little bit about more in your book. What is the secret? I heard, I read the secret to the perfect pie crust. And it's something I would have never imagined. Tell us what that is.

• 5:00Speaker 04

  You know, pie dough seems like it should be simple. It's really just four or five ingredients. There's flour, salt, a little bit of sugar, fat and ice water. The problem is that most recipes are engineered to use a minimum amount of ice water. And the theory is that when the water is mixed with the flour, you are activating the glutens and you're developing this sort of strand of protein network, which is great if you're making bread. It's what gives bread great chew. But in pie dough, it will make it fairly tough. And so you use as little water as possible in order to just get the flour to sort of hold together with the fat. The problem is most recipes don't use enough. And so you go to roll out the dough and it's cracking. It's really difficult to manage. And most

• 5:45Speaker 04

  cooks end up adding more water than the recipe says. A typical recipe for a double crust pie will call for five or six tablespoons of water, but it's really not quite enough. So we said, what is wet that could give us more moisture so that we could hydrate the dough and make it easier to roll out with less cracking, but would not form gluten? And it turns out that alcohol does not form gluten when it's mixed with flour. And so we replaced half of the ice water with chilled vodka in our pie dough.

• 6:14Ira Flatow?

  Do you need a high brand vodka? Fresh, fresh shelf vodka?

• 6:18Speaker 04

  You're not going to taste it because what happens is in the oven when you're baking the pie crust, the alcohol is going to cook off. We tested whiskey, rum, tequila.

• 6:28Ira Flatow?

  What a party that was getting testing.

• 6:30Speaker 04

  Yeah, we have a, we were testing them unfortunately in the pie dough. You cannot taste the difference really between all of them. The important thing is to use something that's 80 proof. It's 40% alcohol. So that you are in effect, we are, our recipe calls for four tablespoons of water and four tablespoons of vodka. But because of the alcohol in the vodka, it's really the equivalent of six tablespoons of water, even though you get the sort of rollability of eight tablespoons of water.

• 6:58Ira Flatow?

  What a trick.

• 6:59Speaker 04

  And it seems like it's a really small trick, but it makes it so much easier to roll out the pie dough. And it's really flaky and it's really tender.

• 7:05Ira Flatow?

  So is, did this come about from actually testing things in the test kitchen, ideas and recipes?

• 7:11Speaker 04

  It's, the test kitchen has about 25 people who work full time who are trained cooks. We also have a science editor. And so this was one of those questions that we discussed with our science editor. We said, what's wet that you could add to pie dough that's not going to form gluten? And he said, well, alcohol. And, you know, then we went into the kitchen and ran a series of tests. Our usual protocols, we'll do sort of one variable test. And so, you know, we'll do a standard recipe with water and then we'll do variations, in this case with vodka. And easy to tell the difference.

• 7:41Ira Flatow?

  So people who have picked up their ears now from hearing this, what's, what's the recipe? How much vodka for how much water?

• 7:47Speaker 04

  So in your, you wanted to use half water and half vodka. If you have a favorite pie dough recipe that calls for ice water, just replace half of the water with chilled vodka. It's really important that the water is cold so it doesn't melt any of the fat in the dough.

• 8:00Ira Flatow?

  Did you decide that people needed to know more about science in the kitchen?

• 8:03Speaker 04

  We really feel like science is the key for many people to finally become a good cook. You know, I think there's a sort of generational issue that many people didn't grow up in homes where they could watch cooking. And so how do you learn how to cook? And a lot of people get frustrated because they make mistakes and think, oh, I shouldn't be making mistakes. Well, make, oh.

• 8:23Ira Flatow?

  You better.

• 8:25Speaker 04

  We're a slave to our timer here. So that means our poached eggs, you're going to have to wait for my answer on this one. So I'm going to take the lid off of the skillet.

• 8:32Ira Flatow?

  Right. Ooh, those are gorgeous.

• 8:35Speaker 04

  Uh, I'm gonna now reach in uh with a slotted spoon to try to take out each of the four poached eggs. Um, I'm going to transfer them to a paper towel lined plates. The paper towel is going to uh soak up the extra water uh that is still on them. The slotted spoon is getting rid of most of the water, but still some in there. And as you can see, they, they came out fairly nice.

• 9:01Ira Flatow?

  Thank you, that's great. Very little white left in the water.

• 9:04Speaker 04

  Very little white. Um, I think you might want to, at this point, season them with a little bit of pepper.

• 9:09Ira Flatow?

  Oh.

• 9:10Speaker 04

  Well, make them taste a little better. And I think, Ari, you have to do, you have the honor.

• 9:15Ira Flatow?

  Somebody has to take over the show while I eat here.

• 9:17Speaker 04

  You at least have to sort of crack in and see.

• 9:19Ira Flatow?

  I gotta, I gotta crack, crack one open. This looks good, cause I, poached eggs are among my favorite food. I need a little English muffin here, I think.

• 9:27Speaker 04

  Yeah, I, I didn't bring the Canadian bacon and the English muffin. Now, five minutes gives you a runny yolk.

• 9:32Ira Flatow?

  That is good. Okay, science. A runny yolk, so if, if you overcook it, it's gonna get a little harder and five minutes works. But the secret, as you said, is not boiling the water, but simmering it.

• 9:46Speaker 04

  And the five minute works, whether you're doing one egg or eight, if you're gonna do more than eight, you might wanna go to six or seven minutes because there's so many eggs in the water. And of course, if you want a more set uh yolk, you could go an extra minute. But for a sort of runny yolk, five minutes is sort of guaranteed to work.

• 10:03Ira Flatow?

  And, and eggs are a good place to start if you wanna learn about the science of cooking, right? There's so many things you can do with eggs.

• 10:09Speaker 04

  It's, you know, they don't call it the incredible egg for nothing, because you really can do so many things, not just different cooking methods. You can, you know, scramble it, you can fry it, you can poach it, but it's a key ingredient in so many uh savory and baked goods.

• 10:23Ira Flatow?

  If you're making scrambled eggs, or you're making just plain sunny side ups, is there a, is there a perfect temperature that you want? People throw the, you know, they heat the skillet up very hot and they throw the egg in and the sizzling, does that wreck the egg? Or do you wanna cook it on a lower temperature?

• 10:37Speaker 04

  For scrambled eggs, the key is fairly high temperature because what you're trying to do is convert the water that's in the eggs, and we also add some half and half to our scrambled eggs.

• 10:47Ira Flatow?

  Oh, you do?

• 10:47Speaker 04

  Yeah. The fat keeps them tender and the additional moisture creates steam, which is what makes them fluffy and light. And so if you're using low temperature for scrambled eggs, if you want really fluffy, light eggs, you're not generating enough steam. So you want fairly high temperature and you have to work really quickly because you don't want them to get tough or brown. For fried egg, we actually heat the pan over low for 10 minutes, trying to get a really even heat, then crank it up so there's no hot spots and add the fried egg.

• 11:16Ira Flatow?

  Should you use a smaller pan, like an omelet pan, for one or two eggs? Or should you use a bigger pan?

• 11:21Speaker 04

  A small pan.

• 11:21Ira Flatow?

  A small pan?

• 11:22Speaker 04

  Yeah.

• 11:22Ira Flatow?

  Okay. A couple of egg lessons. What's the biggest mistake people make with eggs? Is it they use the wrong temperature? Or they just...

• 11:30Speaker 04

  That they don't add enough fat usually. In most egg recipes, what you're doing is you're coagulating the proteins. And, you know, the tendency is to then squeeze out the moisture.

• 11:42Ira Flatow?

  Right.

• 11:43Speaker 04

  And if you add a little bit of fat, whether it's a little half and half in your scrambled eggs, when we make an omelet, we add little cubes of frozen butter to the scrambled, you know, to the eggs that we've sort of beaten by hand, so that there's a little bit of fat in there to ensure a sort of nice, soft set that doesn't squeeze out the moisture in the eggs and make them tough.

• 11:58Ira Flatow?

  Cubes of frozen butter in the omelet? I have to remember that because I love to make omelets.

• 12:04Ira Flatow?

  Coming up after the break, we'll learn more about the science of cooking oils and we'll whip up some eggs into a meringue.

• 12:47Speaker 00

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• 14:56Ira Flatow?

  A lot of great tips in the book, and I want to dive into one in particular, which is the case for brining meat. What is brining meat?

• 15:04Speaker 04

  So, brining meat is the solution to overcooked lean protein. So, we're talking about the white meat in chicken or turkey, lean cuts of pork, like a pork loin or pork tenderloin. There's very little fat, and it can really dry out and be chalky and tough. We've all had a horrible Thanksgiving turkey.

• 15:23Ira Flatow?

  Yes.

• 15:23Speaker 04

  The solution next year is to brine the turkey, and you are putting the protein in a bucket with a solution of salt and water. And what is happening is that the salt is changing the structure of the muscle fibers and creating spaces that can then trap the natural juices in meat. Most meat is 75% water, and the goal is to preserve that natural moisture. And by changing the shape of the proteins, it's actually the sodium and chloride ions have negative and positive charges, and they're changing the way the mosaic of charges on the proteins are working, and you are getting more water to be held into the meat. Its own natural juices, in addition to, obviously, some of the water that's in the brine, makes its way into the meat.

• 16:08Speaker 04

  And basically, we found in side-by-side tests, you can cut moisture loss by 25%, which is really significant.

• 16:14Ira Flatow?

  Doesn't taste salty to me when you take it out?

• 16:16Speaker 04

  You don't want to season it too much. The average amount of salt, if you brine it, is going to be about an eighth of a teaspoon per serving. So, it's about the same if you buy kosher chicken, or if you buy a Butter Bowl turkey, which has been injected with salt. You wouldn't brine those because they already have about that level of salt in them.

• 16:31Ira Flatow?

  All right. We have another wonderful in-studio demonstration that we're going to talk about. What have you got here? I'll let you explain it.

• 16:37Speaker 04

  I have two identical bowls, two identical whisks. Inside each bowl are three egg whites. Now, whipped egg whites are the secret to everything from soufflés to cakes. We are going to both take a bowl and start whisking and see who can make better progress. Come on.

• 17:00Speaker 04

  Now, I know you're gonna say-

• 17:00Ira Flatow?

  I used to be good at this, but this is not working.

• 17:04Speaker 04

  Well, so what we're doing is we're creating a foam here. And as you can see in my bowl, I'm already-

• 17:10Ira Flatow?

  I got nothing.

• 17:11Speaker 04

  Yeah, you got nothing. I actually kinda did something not very nice to your bowl. I sprayed it with a little bit of Pam Cooking Spray.

• 17:20Ira Flatow?

  And Dirty Red.

• 17:22Speaker 04

  The fat is, the point here is that if you get even a teeny bit of fat, and that fat can be leftover grease from not washing the bowl very well, to the fat from the yolk, it will prevent those whites from whipping properly. And you really can't get a stable foam.

• 17:37Ira Flatow?

  No, I was really surprised, because I'd be pretty good at making meringue sort of thing. Or if I make an omelet, I make the eggs yolk separate than the whites and put them back together. Nothing.

• 17:46Speaker 04

  Nothing. And so, you know, it's a really delicate operation. You are taking, you know, a couple tablespoons of liquid whites, and a lot of sort of horsepower in your arm, and turning this into a stable foam. And if there's a little bit of fat in there, it will cause the foam to collapse, or really even just prevent the foam from forming.

• 18:07Ira Flatow?

  So, you wanna make sure then it's a very clean bowl? And you haven't, you know, you haven't put butter or something in it beforehand?

• 18:13Speaker 04

  And never use plastic. It's almost impossible to get a plastic bowl really clean. There's always traces of fat and plastic. So, I had stainless steel bowls here. Glass is fine, but avoid plastic, because it just doesn't really get as clean as it should.

• 18:26Ira Flatow?

  What about the temperature of the bowl? Or, I mean, I've heard people say you may have a cold bowl, or the egg yolk should, the white should be cold. What's with that?

• 18:34Speaker 04

  It is much easier to separate the yolks when they're cold, because the yolks are much firmer and taut, and the eggs will not separate. So, separate the eggs right from the refrigerator. In terms of the whipping, whether those whites are at room temperature or cold isn't going to make much difference in the ability to create a foam.

• 18:50Ira Flatow?

  Are there any new techniques based on science? I've heard people using vacuuming. They vacuum pack the food before they cook it.

• 18:59Speaker 04

  Yeah, I mean, it's a really interesting time in food, because in the world of professional cooking, in restaurants, there's so much science and technology. I mean, molecular gastronomy is really changing the way- A lot of chefs prepare dishes in restaurants. At home, the technology is kind of the same old technology. You know, the microwave sort of came and went and people use a microwave to, you know, warm coffee, but they don't really cook in a microwave. And so the technology, even though, you know, we spend a lot more on the equipment than than we used to in our kitchen, it really is basically the same equipment with nicer finishes.

• 19:30Ira Flatow?

  Let's talk a little bit about the different type of cooking oils. There are so many different ones. What's the science behind which type of oils to use for what purposes?

• 19:40Speaker 04

  So the first thing you want to think about is are you going to be heating the oil? And if you're heating the oil, then the smoke point is hugely important. And in that case, you want an oil with a high smoke point because once the oil starts smoking, it's a sign that it's breaking down and degrading. And so olive oil, for instance, has great flavor, but because it's not fully refined, it has a fairly low smoke point. It's not really great for frying or sauteing. Vegetable oils, soybean oil, corn oil, canola oil, those can withstand more heat.

• 20:10Ira Flatow?

  All of Italian cookery is based on using olive oil, isn't it?

• 20:13Speaker 04

  Well, it's long, I mean, for, yes, most of that olive oil that, I mean, my Italian grandmother would saute in it, but she was using refined olive oil. And so, you know, if you've got a really high-end, extra virgin oil that's got particulate matter in it, you don't want to be frying in it because that means it's going to smoke at a much lower temperature.

• 20:33Ira Flatow?

  So you use a worse grade of oil than to fry in it?

• 20:37Speaker 04

  Well, if you're going to be cooking, yes. You know, for salad, I wouldn't use anything other than really good, extra virgin olive oil. But for cooking, we use a lot of vegetable oil in the test kitchen.

• 20:48Ira Flatow?

  Peanut oil?

• 20:48Speaker 04

  Peanut oil has a great, high-smoked temperature. It has a sort of nice flavor that can add. Most of the flavors are really subtle, so the difference between corn and safflower and sunflower and canola are really very minor. The one thing is, we don't like to fry in canola oil. We find that it gets a little fishy tasting, actually, when it's heated for really long periods of time when you're frying, so we don't fry in canola oil.

• 21:10Ira Flatow?

  Is their one oil healthier, the unsaturated oils?

• 21:13Speaker 04

  I mean, olive oil's probably, you know, and the canola oil get the best marks from the nutritionists. You know, I think we like olive oil, except for super-high heat applications.

• 21:24Ira Flatow?

  Jack Bishop, chef and senior content advisor at America's Test Kitchen. He cooked with us in studio back in 2012 when they released their book, The Science of Good Cooking. And if you like those tips, we're going to have some more for you. Next week, as you get ready for your big holiday meals, we'll have more fun food science.

• 21:47Speaker 03

  Thanks so much, Ira. We are thankful for all the people who make this show possible, including Danielle Johnson. Jason Rosenberg. Dee Peterschmidt. Sandy Roberts. Coming up tomorrow, a look at the science news of the week, including some super loud rockets and a saber-toothed kitten. I hope you can join us. I'm John Dankoski.