Changing the World through STEM: Teen Career Expo
Sheraton Tara, Framingham, MA
girl scouts of eastern massachusetts
October 28, 2012
Hi. My name is Chloe and I absolutely love to cook. I’m here today to share some cool experiments and recipes with you, ones you can try at home and taste test later too! Science is everywhere around us, but I think the easiest way to see it is through looking at the foods we eat and how they are prepared.
These days, much of our food is prepared with a whole different kind of science, with lots of chemicals that make cakes soft and fluffy and preservatives that make milk and butter last for months. Just take a look at the back of the cereal box—I can’t pronounce most of the ingredients, let alone figure out what they are! What interests me the most is the kind of cooking that our grandmothers and great-grandmothers and great-great grandmothers did, and that’s the food that I think we most like to eat anyway.
I’ve always thought cooking is sort of like magic. Lately I’ve come to realize that most of that magic falls down to science, and I think there’s no recipe more magical than bread. You just take some flour and salt and water and a little yeast and let it sit for a while and all of a sudden you have a bubbly amazing thing called bread.
Bread-making has been going on forever—every single culture in the entire world has some type of bread, and almost all of them use some type of yeast. We don’t really know exactly where yeast came from, but some people think that, in a refrigerator-less age of bread-making, some small micro-organisms climbed into the bread dough and the first type of yeast began to develop. That’s exactly what yeast is, it’s like a little creature. Not an animal, but still a living entity that you have to feed. Today we’re going to make a simple, classic bread—All-American Honey Lunchbox bread. This bread is the most versatile I know, and also the simplest.
There are many different type of yeast, but the kind that we’re going to use today is called Rapid Rise yeast. It’s a sort of dry yeast that is reactivated when added to water and feeds off of the sugar and starch in flour to produce carbon dioxide and alcohol. The carbon dioxide bubbles are what make our bread rise and get all bubbly, and the alcohol is what makes it taste nice and bready.
The first thing we have to do is make a little snack for our yeast. Yeast is sort of like us, it likes a nice warm place to live and grow, but not too hot. We’re going to take some warm milk, and some warm water (the water actually makes the bubbles a little bigger) and put them in this measuring cup. We just heated the liquids up a little bit to make a nice lukewarm environment for our yeast to start growing. To this, we’re going to add a little bit of honey and some sugar, which help feed the yeast and also give our bread a little sweetness. There are two ways to make this dough. If you want to get a workout, you can make it on the counter, but if you want to make it nice and quick you can throw it in a mixer with the dough hook. We’re going to do it on the counter just so you can see it from where you’re sitting.
But we don’t want to make a big mess, so we’re just going to start it in a big glass bowl. We put our flour (this is bread flour, which makes our bread nice and chewy and bready, you can get this when you get the yeast!) and our salt and our yeast in a big glass bowl and stir it around a little bit. There are some theories that salt can deactivate the yeast, but recently they figured out that that’s not true, so we don’t have anything to worry about. We’re going to add our liquids and mix it all up with this wooden spoon. Now, we want it to be nice and sticky, but not like cake batter at all—we’re making bread!
We’re going to turn it out onto this floured counter and knead it for a long time—like 10 minutes. I’m just going to do a little of the kneading now because I don’t think you want to watch me knead for 10 minutes, even though it is kind of fun.
We want to get it all nice and elasticky. Bread flour has a really high gluten content, so when you add water to it and mix it around a lot, it becomes like an elastic band. We want our bread to be super chewy, and that comes from how much gluten we can get in it.
Whenever I knead dough, I feel like I’m back in kindergarten feeding the play dough through a little extractor that makes hair, and so I really love it. It’s also a good way to get stress and anxiety out—just grab a hunk of bread dough and go at it!
Over here I have some dough that I made this morning and already kneaded a ton—see how nice and shiny and pretty it is? That’s exactly what you want! The good thing about bread dough is how instinctual it is. If you think you need a bit more flour, you probably do, and you can just throw some in!
Now, we’re going to let this sit for an hour and a half. I like to design my recipes with my dad in mind, because most of the time he’s the one that gets to do the dishes, so I’m just going to use this bowl from before. Just plop this nice little dough ball into the bowl, and cover it super tightly with plastic wrap. This is so that all the carbon dioxide stays in the bowl. We want big bubbles!
I have one here that’s been sitting for that long, and you can see it’s gone crazy!!! I love making this dough on a Sunday while I’m doing homework. I’ll take breaks every once and a while to come and see how much it’s risen—it’s so fun! Resist the urge to let it keep going, you don’t want a kitchen covered in dough, and you don’t want it to ferment too much. A little is good for the flavor, but too much will make it taste like sourdough gone wrong. Trust me, I’ve done it. SO when it’s all puffy like this, we’re just going to gently pat it out on our floured surface so it’s a nice little square. Now, were going to roll it up. Did you ever wonder why the bread is so fluffy and spirally? Well, this is why. If you want to get fancy, you could throw some cinnamon and raisins in at this step and call it Cinnamon Raisin swirl bread. We’re just going to roll it up like a burrito, and then pinch the ends together so you can’t see the seam. You get this nice little compact log. We’ll just put it in this loaf pan, cover it with plastic and let it rise a little more. Right now we’re developing the structure so we have a super yummy bread.
If you baked it now, you’d have a brick, so you need to let it rise one more time for more C02 to develop and puff up like bread.
This one is all done—see how fluffy it looks? Now we just have to bake it in the oven for 45 minutes until it’s all brown and the inside is cooked through. But first, we’re going to spritz a little bit of water on top, so that we don’t get a hard crust at the beginning. WE want it to rise and get soft and fluffy before anything else.
Right here I have a delish bread I baked earlier. This is the absolute best part of bread making! Let’s slice in and see how we did. We want nice thick slices so that we can taste all of our good work. See that fluffy, fluffy crumb. I think we did well
Alright so now that we have some fabulous bread for the most delicious sandwich ever, we need to make another little snack.
We’ve talked about yeast, which I’m betting most of you haven’t spent too much time with, but now we’re going to talk about another thing that makes our cakes and cookies rise: chemical leaveners! We’re going to look at baking powder and baking soda. Some recipes have one, some recipes have both, and some recipes have neither of them at all!
Baking soda is something called an alkali, a chemical that has a pH higher than 7, which means it’s a base. Baking powder is baking soda with an acid added to it.
Today we’re going to make the recipe for my homemade thin mints, just like you guys sell, but super fun because you get to make them at home.
Of course thin mints have to be chocolatey, and chocolate is very acidic. If we added baking powder to our dough, the acid in the cocoa powder would neutralize a lot of the baking soda (which is a base) in the baking powder, and there wouldn’t be enough Carbon dioxide produced and the cookies wouldn’t rise. We already have enough acid in our cookie dough to react with the baking soda to make C02 bubbles, so we’re going to use just baking soda so that they get a little rise.
Making the thin mints is really easy! We’re just going to make a simple dough with some peppermint extract in it, and then later coat it with a thin layer of chocolate.
To start, we need some butter, which will help the cookies to spread! We’re going to make these in a big bowl with a spoon—no mixer required! We’re going to mix the butter (which we’ve melted) with some sugar, and then we’ll add our vanilla and peppermint extract (which you can find at any supermarket these days)! We have some dark chocolate that we’ve melted to give our cookies a really nice chocolate flavor, and we’re going to add that in now too!
Now we’re going to combine our dry ingredients. I like to do this on one of these plastic mats for minimal cleanup which is always a good thing! We have some all-purpose flour—we know from our experiment earlier that this is a good flour for a cookie that’s sturdy enough not to crumble but not tough like a cracker! We’re going to add some cocoa powder, which makes our dough nice and black like a thin mint, and some salt. Salt brings out all the flavors, and without it, the cookies would seem very bland! We have just a little baking soda, which will make them nice and puffy, so that when we let them cool, they will become delicate and crispy! Stir all this together so there aren’t any little lumps, and we’re good to go.
Now we just stir it in with this wooden spoon and let it sit for an hour or so to firm up a little bit. Then we make it into a log, like this one I did earlier, and we’re going to cut thin little cookie—they’re called thin mints after all. When we put them in the oven, the heat will cause the acid and base to react and C02 will be formed.
If you want to try one of my thin mints, stop by the booth at the trade show later—I have enough for an army!
I hope you’ve learned a little something about how science affects your everyday life. I learn something new every day, and I’ve loved having the opportunity to share this with you. I’m working on a service learning project in my community right now, and would love your help to get your school involved in eating healthy and getting active. If you’re interested, stop by my booth and we can discuss it later!
Thanks so much for listening, and have a fabulous day!