Educator How-To: Cross-curricular Education Gets Cheesy

As educators, we all want students to understand the world holistically, but we still tend to teach each subject independent from all other subjects. Food is an effective way to capture the attention of students and provide a useful tool for creating a more global and cross-curricular learning environment. This global approach to learning has been shown to produce deeper understanding of the concepts being taught.

Making cheese, which seems on its face to be a fun break or a supplemental activity, can be used to discover important concepts and ideas that span an entire range of subjects.  These subjects include, but are not limited to, chemistry, history, and geography. Hands-on learning activities help to create interest and to create better retention of learned material.cheese meme

In that spirit, try one of my favorite activities. I use this activity at the Houston Museum of Natural Science to make learning and discovery memorable. It is a culminating activity for my Iron Age lab. It’s simple, affordable, and the kids love it! Why not give it a try?

A Little Bite of Cheesy History

Milk has been a major source of nutrition from the earliest of times. Milk is full of protein, fat, calcium and other important vitamins and minerals. It just so happens that it’s also full of water and sugars, which have no real nutritional value and cause the milk to spoil quickly without refrigeration. With the invention of cheese, man found an ingenious way to prolong the shelf-life of milk.

Because bacteria love a moist and nutrient-rich environment, milk spoils easily. In antiquity, there was no refrigeration, so unless it was cold outside, fresh milk could not be saved from day to day. No one knows how, but our ancestors figured out the trick to preserving milk. They discovered that calves have a substance called rennet in their stomachs that separates the milk solids and fats from the water in the milk they suckle from their mothers. We know that animal stomachs were used to transport and hold liquid, so it’s possible the milk turning to curds and whey was a fortuitous accidental discovery.


Goat stomach still used to make cheese in Sardinia. Photo by Ivano Atzori.

The first cheesemakers found that if they added some rennet to fresh milk, it would soon separate into two separate parts. We call these two parts the curds (where the good stuff is) and whey (mostly made up of water and some sugars). They learned that they could extract even more moisture from the curds if they cut them up and added salt to them, which also had the benefit of adding flavor to the cheese. Heating and pressing were also used to expel additional liquid from the curds. If left to age, molds and bacteria colonized the cheese, making it even more tasty! Thus was born an easy-to-make, non-perishable, transportable food for everyone!

Tasty Science: Make Your Own Ricotta!

Let’s get started! Here’s what you need:

  • 4 cups whole milk
  • 2 cups heavy cream
  • 1 teaspoon kosher salt
  • 3 tablespoons good white wine vinegar
  • Measuring cups
  • Measuring spoons
  • Pots
  • Hot plates (or a stove)
  • Mixing spoons
  • Large bowls
  • Sieves
  • Cheesecloth
  • Water
  • Paper towels

First, set a large sieve over a deep bowl. Dampen two layers of cheesecloth with water and line the sieve with the cheesecloth. Next, pour the milk and cream into a pot and stir in the salt.

Bring to a full boil over medium heat, stirring occasionally. Then, turn off the heat and stir in the vinegar. Allow the mixture to stand for one minute until it curdles. It will separate into thick parts (the curds) and milky parts (the whey).

Pour the mixture of curds and whey into the cheesecloth-lined sieve and allow it to drain into the bowl at room temperature for 20 to 25 minutes, occasionally discarding the liquid that collects in the bowl. The longer you let the mixture drain, the thicker the ricotta.

Transfer the ricotta to a bowl, discarding the cheesecloth and any remaining whey. Use immediately or cover with plastic wrap and refrigerate. The ricotta will keep refrigerated for four to five days.

This is a basic but tasty cheese and anyone can be successful in making it. If you decide to incorporate this activity into your classroom, please share your “cheesy” pictures with HMNS on Facebook or Instagram under the hashtag #HMNS. 

Chemistry in the Kitchen: The Science Behind Ice Cream

Legend has it that the Roman emperor Nero discovered ice cream. Runners brought snow from the mountains to make the first ice cream.

Making ice cream at home is easy – no mountain marathon required! Just read the instructions below and enjoy your very own homemade ice cream.

 Creative Commons LicensePhoto Credit: Jessicafm

Rock salt
Pint-size baggies – heavy duty
Gallon-size baggies – heavy duty
Measuring cup
Measuring spoons

1. Fill the large bag about ½ full of ice.  Add 6 tablespoons of rock salt to the ice.

2. Put ½ cup of milk, ¼ teaspoon of vanilla, and 1 tablespoon of sugar into a smaller baggie and seal.  Put this inside another small baggie and seal.  This will prevent saltwater from seeping into your ice cream.

3. Place the double bagged small baggie into the larger baggie and seal.

4. Shake the baggie until you have ice cream. 

5. Remove the smaller baggie from the larger one.  Wipe off the water, then open it carefully and enjoy your ice cream! 

UPDATE: Check out our Science of Ice Cream video to learn more!

Chemistry in the Kitchen: The Science Behind Butter

 Photo credit: booleansplit

People have been enjoying the rich and wonderful taste of butter for more than 6,000 years.  Archaeologists have found pounds of ancient butter buried in the peat bogs of Ireland.  Butter is still made in essentially the same way as it has been for thousands of years.  Roll up your sleeves and make butter like the ancients!

Heavy whipping cream – you can buy this at the grocery store
Crackers – any kind you like
Clean baby food jar
Butter knife

1. Fill your baby food jar about ½ full with whipping cream.
2. Add a pinch of salt for taste.
3. Seal the cap on tight.
4. Shake your jar up and down vigorously.
5. You will notice that soon you will have a creamy substance that we know as whipped cream.  You’re not done yet!  Keep shaking!
6. Soon you will have a clump surrounded by a liquid.  The clump is your butter and the liquid is buttermilk.
7. Drink the buttermilk if you like, it’s full of protein.
8. Place your butter in a piece of cheesecloth and squeeze the excess liquid out.
9. Use your butter knife to spread your creation on crackers and enjoy!

When milk straight from the cow is left to stand it separates into skim milk and cream.  The cream rises to the top.  The cream is full of proteins and fat.  When you shake the cream and agitate the fat globules, they stick together to form butter.  The leftover liquid is called buttermilk and it is full of protein. 

Interested in learning more about cooking and the science behind it? BEYONDbones will be bringing you The Science of Food – a series of videos exploring the science involved in the culinary creations of some of the best chefs in town. Its all part of Big Bite Nite on April 30, an event featuring food from over 30 restaurants all in one location – HMNS.

Science Doesn’t Sleep (9.8.08)

Bacteria loves milk.
Creative Commons License photo credit: IRRI Images

So here’s what went down after you logged off.

A NASA administrator insists he backs the upcoming retirement of the space shuttle (leaving the U.S. unable to send astronauts to the International Space Station)  – despite a leaked e-mail to the contrary. Oh – and, the BBC reports that Chinese astronauts (called yuhangyuan) will perform their first-ever spacewalk.

Got bacteria? New research indicates that you shouldn’t be washing your antibiotics down with milk.

Bad news for mathletes: using your brain might be making you fat.

NPR asks: Can physicists be funny? (The answer is YES.) Scientists at CERN are going through improv comedy training to help reassure the public that they’re not about to create a giant black hole that will swallow the Earth.

Arctic permafrost holds twice as much carbon as the atmosphere – making it a potential environmental threat. Good thing it’s not melting at a disturbingly fast pace.

Does the President need to be tech-savvy?