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Spring is in the air. What a wonderful opportunity to get outside and go for a walk. Do you have a favorite trail or park to visit? What about the local nature center, arboretum or botanical garden? Take a few minutes from your hectic schedule and go on a stroll.

While you are outside, take a look around at the spring flowers. In some areas you may see the pussy willows just starting to bud and snowdrops peaking through melting snow. In other areas, the poppies may be starting to wane as the heat builds up. Wherever you may be, stop and enjoy the color and beauty of flowers.

You might be wondering what a nature hike has to do with science, even though it is certainly fun. It turns out you can do science while on a nature hike and it won't even be hard.

Take a closer look at the flowers you find. Notice if you can smell anything. Are the flowers all one color or are they a mix of colors within a single flower, like the darker orange patches in the yellow flower below? Are there any insects around? Observing is an important science skill, which is simple to do and can lead to further explorations. Do you find the plants in a certain place, such as out in the open or hidden under some brush? Do the plants change over the season? All of these observations can lead to further questions and even to experiments.

Do you know what kind of plants you are finding? Classifying is another important science skill, but it doesn't necessarily mean you have to learn the scientific name of everything you see. Classifying can simply mean grouping things based on similarities and differences. For example, you can group all the flowers you see based on the their color, leaf shape or size. Is the flower you are seeing now is the same as the one you just saw over there, or is it different? With children, start a conversation about how they would name the flowers. You can also ask how they would find out the name others have given the flowers.

When you get home, you might want to look up the common and/or scientific names of one or two of the flowers. There are many excellent books or you can use Internet sites like this one from Texas. In any case, hope you have an enjoyable weekend.

nasturtium

The Science of Making Cheese

Little Miss Muffet
Sat on a tuffet,
Eating her curds and whey;
There came a big spider,
Who sat down beside her
And frightened Miss Muffet away.
~ Mother Goose

What are "curds and whey?" Where does cheese come from? Let's make some homemade cheeses and find out!

The easiest cheeses to make are the so-called soft cheeses like cottage and ricotta cheeses. To make a soft cheese, simply add an acidic substance like lemon juice or vinegar to warmed milk. The proteins in the milk clump or coagulate together forming the curds. The curds are then separated from the remaining cloudy, yellowish liquid, which is called the whey. When making cheese at home, the whey is discarded. When cheese is made commercially, the whey is often collected and added to baked goods and other foods.

In contrast, making hard cheeses, such as cheddar, is more complicated and requires more time. Usually, instead of the lemon juice or vinegar, an enzyme called rennin is used to coagulate the milk proteins. Once the curds are formed, they are ripened by the addition of special molds or bacteria to create distinctive flavors. The mold can actually be seen in blue cheese, it gives the cheese its blue color. During or after ripening, the curds are pressed to create blocks or bricks.

Following are recipes for two soft cheeses. One is made from cows' milk, the other from soymilk.

Cottage Cheese
Note: This project will require adult assistance and supervision. Hot, thick liquids like milk can boil over quickly and unexpectedly.

Utensils:
A colander or strainer
A large bowl
Cheesecloth (white cotton cloth for food use, available at many grocery stores, or use clean paper towels if no cheesecloth is available.)
Saucepan
Long-handled spoon
Stove

Ingredients:
2 cups of cows' milk, any kind
3 Tablespoons of lemon juice or vinegar
Directions:
1. Place the colander over the bowl (or in if the bowl is big enough). Line the colander by draping layers of cheesecloth (or paper towel) over the sides.
2. Pour the milk into the saucepan. Add the lemon juice or vinegar. Place the saucepan over low heat and stir slowly until the milk curdles (forms soft lumps and clumps). This usually takes about five minutes. Remove the saucepan from the heat. Let stand for ten minutes to let the curds (clumps) and whey (liquid) form and separate somewhat.
3. Pour the curdled milk into the cheesecloth. Allow the whey to drip through. Catch the solid part, the curds. Once most of the liquid seems to have moved through the cheesecloth, pull the edges of the cheesecloth over the curds and press gently to remove as much of the whey as possible. Once the curds are approximately the consistency of commercial cottage cheese, which should be in 15-20 minutes, they are ready to eat. Transfer to a clean container, cover and refrigerate if not used immediately.

Are you allergic to dairy products? Here is a dairy-free cheese.
Soy Ricotta Cheese
Note: This project will require adult assistance and supervision. Hot, thick liquids like soymilk can boil over quickly and unexpectedly.
Utensils:
A colander or strainer
A large bowl
Cheesecloth (white cotton cloth for food use, available at many grocery stores)
Sturdy, heavy-bottomed saucepan, or double boiler if available
Long-handled spoon
Stove

Ingredients:
1 Quart unsweetened, unflavored soymilk (or smoothly blend 1 cup soy flour in 1 quart of water)
3 Tablespoons of lemon juice or vinegar
Directions:
1. Place the colander over or in the bowl. Line the colander by draping layers of cheesecloth over the sides.
2. Pour the soymilk into the heavy-bottomed saucepan or top of the double-boiler. Place the saucepan over low heat and stir constantly until the soymilk boils. Watch closely and stir frequently, because the soymilk burns easily. If the soymilk begins to burn (brown or blacken at the bottom of the pan) quickly transfer to another pan and continue stirring. Transferring will lessen the chances of a burnt flavor.
3. Remove the saucepan from the heat. Add the lemon juice or vinegar and stir. Let stand for twenty minutes to let the curds (clumps) and whey (liquid) form and separate somewhat.
4. Pour the curdled milk into the cheesecloth. Allow the whey, or watery part to drip through. Catch the solid part, the curds. Once the liquid seems to have moved through the cheesecloth, pull the edges of the cheesecloth over the curd and press gently to remove as much of the whey as possible. Once the curds are the consistency of cottage cheese, they are ready to eat. Optional: add salt, diced tomatoes or herbs.

These soft cheeses work well in lasagna or in enchiladas, too.

Today let's do some bubble science. Most of us have used bubble formulas or solutions sold in stores, and they make great bubbles. But what if you are out of bubble formula and can't get to the store to buy any? Are there any other products you already have around the house that will make bubbles? You probably can think of a couple of things right off hand. Now let's give them a try.

Part 1. Testing the products
You will need:

-A bubble wand or similar tool for blowing bubbles, such as a spool
-A few small containers, such a small paper cups, big enough for the wand to easily fit inside
-Water
-Household products to test, such as dish detergent, shampoos, hair conditioners, toothpaste, laundry soap, hand soap, hand sanitizer, sunscreen and hand cream. You might also want to try blowing bubbles in milk and cream, without adding water. Use your imagination to come up with things to test. Note: Stay away from potentially dangerous products such as toilet bowl cleaners.

First, try to blow a bubble with just water. Can you do it? Put some water into a container, and then swish it with the bubble wand and blow. What happens?

Dump out your test compound after each test into a sink and rinse the container completely, or use a fresh container for each test so the products don't interfere with each other.

Squeeze a nickel-sized blob of household product in a container and add about the same amount of water. Stir the mixture with the bubble wand. What happens? Do any bubbles form? Now, load the wand and try to blow a bubble. Does it work? If not, try to add a bit more water and try again.

What about toothpaste? Doesn't it make small bubbles when you brush your teeth? Could you blow a bubble with your toothpaste?

After you have tested all the different products, which gave the best bubbles? Typically dish detergents and shampoos should work well, but some brands are better than others. If none of the products made good bubbles, then you might want to try again using bottled water with your products. Tap water can have minerals or other chemicals in it that make it difficult for bubbles to form.

Part 2. Improving the formula

You will need:
-Equipment from Part 1
-Household products that worked best for producing bubbles, from Part 1
-Sugar
-Corn syrup
-Water

Commercial bubble formulas often contain glycerin to help the bubbles last longer. But glycerin is expensive and may be an allergen. Will adding sugar or corn syrup make bubbles last longer?

Try this recipe. Mix 1/2 cup of your best product with 1/2 cup water in a container. Try a few bubbles. Then add 1/4 cup of granulated sugar and stir well. Try blowing a bubble. Do the bubbles seem any different after the sugar was added? What about the marks the bubbles leave after they pop? Do the marks seem different?

Now mix 1/2 cup of your best product with 1/2 cup water again. This time add 1/8 cup of corn syrup and mix well. What happens to the bubbles this time? Which mixture do you prefer?

If you are interested in finding out more about bubbles and doing more bubble experiments, be sure to check your local library for books on bubble and soap science.