Moooooo Science! Making glue

Moooo Science Overview: Students will add vinegar to milk to separate the curds and whey. The curds will be mixed with baking soda and water to create the glue!

Materials: Safety goggles (this is chemistry), 9-ounce paper cups, plastic spoons, coffee filter, powdered milk, vinegar, baking soda, measuring spoons, measuring cups, hot water, zip-lock baggies.

Procedure: Per Group Measure ¼ cup hot tap water (not boiling, but very hot) and put into a 9-ounce paper cup. Add 2 tablespoons of powdered milk to this water. Stir to dissolve. Add 1-tablespoon vinegar to this mixture. Stir until well separated. You should see chunks of curd and watery whey. (It works best with very warm to hot milk, that is why we use powdered milk and hot water.) (If the milk does not separate well, try a little more vinegar)

3. Milk has a protein called casein (Kay-seen) in it 3.      Milk has a protein called casein (Kay-seen) in it. When milk sours, or has a slight acid (vinegar) added, the casein clumps to form curds (also used to make cheese). Whey is the watery material left behind. To separate the curd and whey, you line the second paper cup with a coffee filter, and then pour the mixture into the filter. Slowly lift the filter out. The whey will stay in the cup and the curd will be on the filter. We want the curd. 4.      Squeeze the filter to remove as much of the whey as possible from the curd. Drop the clump of curd back into your first cup. Discard the whey in the sink. Do not throw away this cup and rinse the sink.

5. Use a spoon to break up the curd. This is important! 6. Add one teaspoon of hot water and 1/8-1/4 teaspoon baking soda and mix thoroughly. You should see some slight foaming. The baking soda reacts with the vinegar in the curd. This should make the curd un-clump! It is now glue! If it is too thick, carefully add some extra water. If it’s too lumpy another pinch of baking soda should help. It should have the consistence of a thick liquid to a paste.

7. The liquefied casein is natural glue 7. The liquefied casein is natural glue. It is used in food products such as non-dairy creamers. We will use the glue tomorrow in class

8. Write your name on a baggie 8.       Write your name on a baggie. Spoon glue into the baggie, squeeze out all air possible and close. Leave at you lab area for tomorrow. Plus

There is no “whey” you can mess this up!