Kitchen Classroom: Week 19

Welcome to Kitchen Classroom, where America’s Test Kitchen Kids is sharing a weekly set of kid-tested and kid-approved recipes, hands-on experiments, and activities paired with suggestions for how to bring learning to life in the kitchen. 

This week, kids can take hands-on cooking to the next level by preparing Smashed Cucumber Salad, enjoying refreshing Mango Lassi Popsicles, making the most of a bounty of summer produce with Vegetable Tacos (starring zucchini and corn), and learning about the powerful science of salt with a batch of Zucchini Muffins. 

Don’t forget to share what your family makes by tagging @testkitchenkids or using #atkkids on Instagram, or by sending photos to kids@americastestkitchen.com. Visit the America’s Test Kitchen Kids website for more culinary content designed especially for kids, plus all of the Kitchen Classroom content in one easy-to-scan location. 

Here’s what’s cooking for the week of July 20th through 26th.

These refreshing popsicles are inspired by lassis—yogurt-based drinks that are popular in India. Lassis are often flavored with spices or fruit, such as mango. Designed especially for young chefs ages 5 to 8, this recipe combines fresh or frozen mango chunks, yogurt, honey, and lime juice in a food processor and freezes the mixture into popsicle molds. (Be sure to save 1 to 2 tablespoons of mango mixture for the Learning Moment, below.) Don’t have popsicle molds? In a pinch you can use paper or plastic cups and wooden craft sticks instead. Kids will have fun making—and eating—this sweet treat that helps beat the summer heat!
[GET THE RECIPE]

What You’ll Need
1½ cups (10 ounces) fresh or frozen chopped mango
1½ cups plain yogurt
¼ cup honey
1 tablespoon lime juice

Learning Moment
Science (States of Matter):
Ask kids what they know about the process of freezing:

• What does it mean when something freezes? (It loses heat and, as a result, turns from a liquid into a solid.)
• At what temperature does water freeze? (32 degrees Fahrenheit)

Explain to kids that mango, yogurt, honey, and lime juice all contain a fair amount of water, so they will transform from a liquid to a solid when their temperature drops below 32 degrees Fahrenheit. Ask kids to predict what they think happens to the liquid mango mixture in the freezer? Does part of the mixture freeze first? Or does the whole thing go instantly from a liquid to a solid? 

Kids can watch freezing in action by pouring the reserved 1 to 2 tablespoons of liquid mango mixture into a small paper or plastic cup (you can use water instead). Have kids place the cup in the freezer and observe it every 30 minutes until it is frozen solid (remove the cup from the freezer for observations). Kids can use a toothpick or skewer to gently touch different areas and observe which are liquid and which are solid. Which areas freeze first?

Kids will likely notice that the liquid in the cup freezes from the outside, in—the surface and sides of the liquid touching the cup become solid first. That’s because they are closest to the cold air in the freezer. The liquid is warmer than the air in the freezer, so some of the heat energy from the liquid moves into the colder air. It takes longer for the heat energy in the center of the liquid to reach the colder air, so it stays liquid (and warmer) longer. Kids can also observe this process as ice cubes freeze in their tray. A thin layer of ice will form around a center that remains liquid. (And kids should feel free to eat their mini popsicle!)

Take It Further
Social Studies (Food Culture):
Lassis are Indian beverages that are also popular in Pakistan and Bangladesh. People drink lassis year-round, but especially in the hot summer months, since they’re served cold. Lassis traditionally include yogurt, milk or water, and a blend of species and or sweeteners, like sugar. There are many, many different varieties of lassis, they can be sweet or salty, some are made with fruit, while others are flavored with herbs, spices, rosewater, or ginger. Mango lassis are popular in India as well as here in the United States. Ask kids to find India on a map. What continent is it on? Ask them what other lassi flavors they might like to try. 

This recipe is based on a dish from the Sichuan region of China called Pai Huang Gua that is typically served as an accompaniment to rich, spicy dishes. Smashing the cucumbers, rather than chopping them, creates more craggy surface area for the vinaigrette to cling (see the Learning Moment, below, for a kid-friendly experiment that demonstrates this). Young chefs of all ages will have fun smashing the cucumbers with a skillet and mixing up the dressing. This recipe calls for rice vinegar, but you can substitute black vinegar, which is more traditional in this dish, if you like. If you can’t find Persian cucumbers, you can substitute 1 English cucumber, cut crosswise into three equal lengths—it will be a bit more challenging to smash.
[GET THE RECIPE]

What You’ll Need
5 (3-ounce) Persian cucumbers
¼ teaspoon salt
2 teaspoons rice vinegar
1½ teaspoons low-sodium soy sauce
½ teaspoon toasted sesame oil
½ teaspoon sugar
½ teaspoon sesame seeds, toasted

Learning Moment
Math (Geometry); Science (Observation skills):
In steps 1 and 2 of this recipe, kids smash and tear cucumbers into pieces. Ask kids why they think this recipe asks them to smash the cucumbers instead of slicing them with a knife? Then, conduct a simple experiment to find out!

Reserve one Persian cucumber (or ⅓ of the English cucumber, if using). Have kids smash the remaining four Persian cucumbers as directed in step 1 and then use a knife to slice the remaining cucumber in half lengthwise and then crosswise into 1-inch pieces. In step 4, have kids set aside 1 teaspoon of the dressing in a small bowl. Add the sliced cucumber to the small bowl and toss to combine. Then, toss the four smashed cucumbers with the remaining dressing, following the instructions in step 4. 

Have kids observe and taste both bowls of cucumbers. What do they notice? Do the cucumbers look different? Is their flavor different? Is their texture different? Does the dressing cling to the smashed cucumber the same way it clings to the sliced cucumber?

Smashing the cucumbers changes their texture—and their shape. It exposes more of their surface area and it creates a more bumpy surface on the cucumbers (as compared to slicing them into smooth circles). This helps more of the dressing stick to the cucumbers, so you get even more flavor in every bite!

Soggy muffins are a sad sight. Luckily, a key ingredient (salt!) keeps these muffins light and fluffy. Kids will perform an experiment to see how salt draws out moisture from watery vegetables like zucchini for a perfectly baked breakfast treat. Be sure to read through the Learning Moment, below, for how to turn this tasty recipe into a fun experiment.
[GET THE RECIPE]

What You’ll Need
Vegetable oil spray
1½ pounds zucchini (3 medium or 2 large zucchini)
½ teaspoon plus 1 teaspoon salt, measured separately
1 cup (5½ ounces) whole-wheat flour
1 cup (5 ounces) all-purpose flour
1 teaspoon ground cinnamon
1 teaspoon baking powder
1 teaspoon baking soda
¼ teaspoon ground nutmeg
2 large eggs
¼ cup vegetable oil
1 teaspoon vanilla extract
1 cup (7 ounces) plus 2 tablespoons sugar, measured separately

Learning Moment
Science (Physics):
Vegetables and fruits like zucchini (a zucchini is technically a fruit!) are made up of mostly water. A big challenge when you’re cooking or baking with them is dealing with all that water—no one likes a watery stir-fry or a soggy muffin. Explain to kids that one of salt’s many superpowers is that it can pull water out of food. Plants (and animals) are made up of countless tiny cells. When you sprinkle salt on plants like zucchini, some of the water inside the food’s cells is pulled out towards the salt. This process is called osmosis (“oz-MOE-sis”). 

To observe osmosis in action, at the end of step 2, have kids split their pile of shredded zucchini in half. Have them put half of the zucchini into the strainer with ½ teaspoon salt and let sit as described in step 3. 

Meanwhile, have kids take out two small juice glasses that are the same size. Have them squeeze the unsalted zucchini over a bowl as described in step 4, and transfer that liquid into one of the juice glasses. When the salted zucchini is ready, repeat squeezing and transfer the liquid to the second juice glass. Place the two juice glasses next to each other and compare the amounts of liquid. Ask kids: Did the salted or unsalted zucchini lose more liquid? (The salted zucchini should have lost about twice as much liquid as the unsalted zucchini.) 

Explain to kids that squeezing the shredded zucchini in a towel gets some of the water out, but salting it and letting osmosis do its work lets you squeeze out double the water. This is especially helpful when you’re cooking with zucchini, because about 95 percent of a zucchini is actually water! If you don’t salt your zucchini, you’ll wind up with more water in your muffin batter, which will bake into soggy, squat muffins.

After making their observations, have kids combine and stir the salted and unsalted zucchini back together and continue making the recipe from step 5.

These vegan tacos feature crisp-tender zucchini and corn paired with creamy mashed black beans. If you want to make the most of summer produce, try swapping fresh corn kernels for frozen. Serve these tacos with your favorite toppings, such as hot sauce, diced avocado, chopped cilantro, sour cream, Cabbage Slaw, and/or Pickled Red Onions.
[GET THE RECIPE]

What You’ll Need
1 (15-ounce) can black beans, opened
1 tablespoon lime juice, squeezed from 1 lime
2 teaspoons plus 1 tablespoon extra-virgin olive oil, measured separately
¼ teaspoon plus ½ teaspoon salt, measured separately
2 garlic cloves, peeled and minced
1 teaspoon ground cumin
½ to 1 teaspoon chili powder
1 zucchini, trimmed, quartered lengthwise, and cut into ½-inch pieces
1½ cups frozen corn
8–10 (6-inch) corn tortillas

Learning Moment
Math (Measurement):
Once kids start cooking, this recipe comes together quickly, so it’s important that they have all of their ingredients measured into individual bowls before they begin. Plus, some of the ingredients are measured twice, because they’re used in different recipe steps. Once kids have finished measuring, ask them to organize their ingredients from greatest amount to least, omitting the tortillas. Here’s the correct order of ingredients in this recipe with volume measurements, along with approximations for garlic and zucchini:

• 1 (15-ounce) can black beans, opened
• 1½ cups frozen corn
• 1 zucchini, trimmed, quartered lengthwise, and cut into ½-inch pieces (about 1 to 1½ cups)
• 1 tablespoon lime juice
• 1 tablespoon extra-virgin olive oil
• 2 garlic cloves, minced (about 2 teaspoons)
• 2 teaspoons extra virgin olive oil
• 1 teaspoon ground cumin
• ½ teaspoon salt
• ½ teaspoon chili powder
• ¼ teaspoon salt

Catching up on Kitchen Classroom? Find previous weeks using the links below:

• Kitchen Classroom: Week 18
• Kitchen Classroom: Week 17
• Kitchen Classroom: Week 16
• Kitchen Classroom: Week 15
• Kitchen Classroom: Week 14
• Kitchen Classroom: Week 13
• Kitchen Classroom: Week 12
• Kitchen Classroom: Week 11
• Kitchen Classroom: Week 10
• Kitchen Classroom: Week 9
• Kitchen Classroom: Week 8
• Kitchen Classroom: Week 7
• Kitchen Classroom: Week 6
• Kitchen Classroom: Week 5
• Kitchen Classroom: Week 4
• Kitchen Classroom: Week 3
• Kitchen Classroom: Week 2
• Kitchen Classroom: Week 1