pH at the Botanic Garden

Why do lemons taste sour?

by Shakayla Clark-Day

On the first day of HOPS at the Botanic Garden we tested the pH levels of sterem water, orange juice, and lemon juice. The lemon juice was not processed or watered down, so it stood out the most to me. I wondered what kind of acid was in lemons to make lemons taste the way they do. The ph value in lemons is 2.0. I have tasted a lemon before so I know that they are sour. Lemons smell fresh and pure. Lemons feel smooth and soft.

You may not know that lemons have mild acids. Lemons have ascorbic acid and vitamin C.

Lemons are sour because they have what we call citric acid. When you bite into a lemon it triggers your taste buds. ‘’Your taste buds let you know when something is sour.” To explain what I just said in a scientific way, you need to understand what acid is. Acid is a solution of molecules that produce hydrogen ions. Hydrogen ions is a proton without its electron. The symbol for a hydrogen ion is H+ . Your tongue has 3 receptors. One of them detects when something is sour, and it's located on the side of your tongue.

Why do you think lemon taste sour? There are tiny receptors in your mouth, letting your brain when something is sour, salty, bitter and sweet. Some of those H+ ions land on those tiny receptors send a signal to your brain. All lemons don't taste the same; they taste different. It's because some lemons have higher doses of citric acid then others. When you bite into a lemon the side of your mouth is telling your brain that something is sour or bitter.

pH is the measurement of hydrogen that focuses on H+ ions. A ph chart measures the acidity of a solution. pH charts usually range from 0-14. The lower the solution is on the chart the more acid is the substances in it. Lemons have a ph of 2.0 and 2 is close to zero and because lemons are close to zero that means that the lemons have a lot of acid in them.

When you eat lemons you feel a sour taste on your mouth. Y'all need to remember that citric acid gives lemons its sour taste . The next time you drink or eat something, think about what might be in it. The next time you make lemonade and it's sour, add water to dilute the citric acid. There are many uses for lemons. Lemons can help your throat if it's sore; lemons can also help if your stomach is upset. Lemons can be used for cleaning, in particular, pots and pans. If you rub a lemons on a fork then run hot water on the fork it will be clean. Research on what why are lemons are sour will continue because it was so much fun learning about lemons .


-CITRIC- fruits having a slightly sweet taste taste

-ION- an atom or molecule that has a charge

-pH - a measurement of hydrogen ions in a solution; tells how acid a solution is