Creating a pH Sensor Using Blackberries: A Step-by-step Guide
Discover a simple and cost-effective method to create a pH indicator at home using blackberries, requiring no specialized equipment or chemicals. This fun science project is perfect for introducing the concept of pH and indicators to students or as a DIY activity.
Materials Needed
- Water
- Blackberries
- A pan
- Heat source
- Spoon
- Vinegar
- Baking soda
- Toothpaste
- Containers for testing
Instructions
- Collect a handful of blackberries and add them to about 200ml of water. Optionally, add a little distilled water to help extract the pigment.
- Crush the blackberries gently to release their juice. Strain the mixture through a fine mesh or cheesecloth to remove solids, collecting the liquid which contains the anthocyanins.
- Anthocyanins change color depending on the pH of the solution they are in. In acidic solutions (pH < 7), the juice typically appears red or pink. In neutral solutions (around pH 7), the color shifts toward purple. In basic or alkaline solutions (pH > 7), the juice may change to blue, green, or yellowish hues.
- To preserve the anthocyanin pigment in your homemade indicator, store the extract in a cold, dark place or refrigerator, as exposure to light and heat speed up degradation.
Additional Tips
- If you want a more concentrated extract, you can heat the crushed fruit gently in a small amount of water (do not boil) to help release the pigments, then strain.
- Red cabbage is another popular and effective source of anthocyanin for pH indicators, often used in educational settings.
- Use small clear containers or white paper to observe color changes clearly.
- Avoid adding other substances that could interfere with the pigment's color.
By leveraging the natural pH-dependent color shifts of anthocyanins, blackberries and similar fruits become practical for creating homemade pH indicators. This simple natural indicator provides a visible color change to detect acidity or alkalinity of common household liquids.
Last updated on August 6, 2025 by Emma Vanstone.
- The homemade pH indicator created using blackberries can also serve as a valuable tool in the realm of health-and-wellness, as it allows individuals to easily test the pH levels of food-and-drink items, such as fruits or beverages.
- In addition to pH testing, this DIY science project can be extended to explore fitness-and-exercise, as the renewed interest in health and wellness might prompt users to consider the effects of diet and physical exercise on their overall pH balance.
- With an understanding of the concept of pH visually demonstrated through this simple science project, one can also gain appreciation for the role of pH in various aspects of lifestyle, such as skincare products or water purification systems.
