There are over 200 different types of potatoes in the world but all of them contain mainly 2 things: starch and moisture. That being said the amount of water a potato can absorb is directly related to the amount of starch it contains (The Science of Good Cooking). For this reason I am testing two types of potato to see if one absorbs more water than the other.
Picture 1 - From left to right red bliss, russet, and sweet potatoes. I didn't collect any data on the sweet potatoes because the red dye was too hard to see in the orange color.
Picture 2 - pieces of potato after they had been boiled in the red water
My hypothesis for this experiment was: If a potato has a lot of starch they will absorb more water than if the potato does not contain a lot of starch. The null hypothesis for this experiment was that the amount of starch in the potato would not affect the amount of water absorbed by the potato. The standardized variables for this experiment was the same pot and amount of water and amount of dye in the water.
For this experiment I needed:
- potato (russet and red bliss)
- pot
- food coloring (preferably blue but I only had red)
- ruler
I cut up multiple half inch sections of each type of potato (red bliss and russet). I added water to a pot (enough to cover the potatoes) and added the red food coloring until it was a dark red color. Once the water came to a boil I placed my potato pieces into the water and boiled them until they were cooked through.
After the potatoes had cooked I took them out of the water and measured the amount that the red dye had soaked into the potato in millimeters.
Picture 4 - This graph shows the average absorption of the dyed water by the potato. Clearly the Russet Potato absorbed way more water than the Red Bliss Potato.
As shown above in the graph you can clearly see that the russet potatoes absorbed more water than the red bliss potatoes. This is directly due to the amount of starch in russet potatoes. Because of this I can accept my hypothesis and say the amount of starch does have an effect on the amount of water absorbed. According to The Science of Good Cooking russet potatoes have a higher starch content than red bliss potatoes they absorbed more water and turned red all the way through versus the red bliss potato that only turned red on the outside but none soaked in.
Until next time.


