Tuesday, January 7, 2014

simple potato osmosis lab

Osmosis is best defined as the movement of water molecules across a membrane from an area of high water concentration to an area of lower concentration. This lab shows osmosis in action.  All you need are a few potatoes, 3 plates, some water, and a couple spoons of brown sugar.

  1. Cut 2 potatoes in half, you will need 3 potato halves for this experiment. 
  2. Remove the skin on one side so the potato has a good flat surface to place in the water.
  3. Cut a ~1 inch square out of the rounded side of each potato.
  4. Place 1 prepared potato in boiling water for 10 minutes; cool for 5.
  5. Place all 3 potatoes flat side down on a plate with a shallow water reservoir and label them.
  6. Potato 1 is the control. Potatoes 2 & 3 carefully add brown sugar to the square cut, lightly packing it.
  7. Leave overnight and observe the changes.

We saw results within 6 hrs.  The control potato did nothing whereas potato #2 (the raw sugar packed potato) water had traveled through the potato to the sugar.  Potato #3 (the boiled potato with sugar) water had also traveled through the potato to the sugar but at a much slower rate do to the damage done to the cells by heating it.

 We love science! 


  1. Brilliant, I've never seen this one before - thank you! We finally got round to doing celery in coloured water recently so this will be a perfect follow-up.

  2. That's interesting, fun and perhaps tasty too. Would it work if the potatoes were in the refrigerator?