Making ice cream in three minutes or cooking pasta using one minute of power is possible with a sprinkle of science.
Yokohama National University professor Shoko Shibukawa has been researching the science of cooking for more than 20 years. Last week on Japanese television, she showed how to cook a few things in a small period of time.
1. Homemade icecream in three minutes.
Ingredients: 100mL milk, 100mL full cream, 2.5 tablespoons of sugar
Step 1: Mix the ingredients together.
Step 2: pour the mixture into a resealable bag, and try to flatten out the bag as much as possible when closing it up to make sure there is little air inside.
Step 3: place the bag inside a larger bag filled with ice cubes and salt.
Step 4: wrap the step 3 in a large towel.
Step 5: spin or shake the towel and its contents around for about three minutes. To make sure the bag does not fall out of the towel, it may be an idea to tie knots around the bag using the towel.
Step 6: Take out your ice cream and serve.
Why does it work?
According to Ms Shibukawa, the temperature inside both a freezer and a bag containing ice and salt is -10 to -20C. The difference is that a freezer cools things down by blowing around cold air, but the ice cream bag contains little or no air. Ms Shibukawa says cream cools down faster in an environment where there is no air. The shaking and spinning ensures that the rapidly cooling cream mixes with the warmer cream in the middle of the bag.
2. The eco-friendly way to cook pasta.
Step 1: Heat up water in a pot until it boils, then add pasta.
Step 2: After a minute or so, switch off the stove, cover the pot with a lid, and leave for seven, eight minutes.
Step 3: serve pasta.
Why does it work?
Boiling water has a temperature of about 100C. According to Ms Shibukawa, you only need the water to be more than 80C to break down the starch in pasta. The temperature will only drop down to about 90C seven or eight minutes after switching off the stove.
The rate the temperature drops can vary depending on the size of the pot, and amount of water, she says. It is important to make sure there is more than enough water to cover the pasta, but not too much it looks like the pasta is drowning in the pot.
Photos from Japan’s NTV television network show “The Most Useful School In The World”. http://www.ntv.co.jp/sekaju/onair/091128/02.html