Examples of Homemade pH Indicator: 3 Easy Examples You Can Actually Do

Before we talk theory, let’s get to the fun part: color changes. When people ask for examples of homemade pH indicator: 3 easy examples, I always come back to the same trio because they’re cheap, safe, and dramatic:

• Red cabbage juice
• Turmeric solution
• Hibiscus tea

These three are some of the best examples of kitchen chemistry in action. They each behave a little differently, which is perfect if you’re planning a science fair project and need data to compare.

Example of a Classic: Red Cabbage pH Indicator

If you only try one homemade pH indicator, make it red cabbage. It’s the classic example of homemade pH indicator you’ll see in textbooks, classrooms, and science museums.

Why red cabbage works

Red cabbage is packed with pigments called anthocyanins. These natural dyes change color depending on how acidic or basic a solution is. The same family of pigments shows up in blueberries, blackberries, and some purple flowers. According to chemistry education resources from the American Chemical Society and university outreach programs, these anthocyanins are widely used as teaching tools for acids and bases.

How to make the indicator

You can describe this in your science fair logbook as a simple extraction:

1. Chop about 1 cup of red cabbage into small pieces.
2. Add the cabbage to a blender with 2 cups of water and blend until the water is a deep purple.
3. Strain out the solid pieces using a coffee filter, paper towel, or fine strainer.
4. Collect the purple liquid in a clear jar or cup—this is your cabbage pH indicator.

If you don’t have a blender, you can pour hot (not boiling) water over the chopped cabbage and let it sit for 15–20 minutes, then strain.

Real examples of acids and bases to test

Here are several real examples of household liquids you can test with your cabbage indicator:

• White vinegar
• Lemon juice
• Baking soda dissolved in water
• Soapy water (dish soap in water)
• Club soda or seltzer
• Milk
• Tap water
• Window cleaner (check the label and use with an adult)

When you add a small amount of cabbage indicator to each sample (or vice versa), you’ll see a rainbow of colors:

• Strong acids (like vinegar, lemon juice) turn the indicator pink or red.
• Weak acids (like soda) may turn it light pink.
• Neutral or close-to-neutral solutions (like plain water or milk) stay purple or slightly blue.
• Bases (like baking soda solution, some soaps) turn it blue, green, or even yellowish-green.

These color changes give you one of the clearest examples of homemade pH indicator: 3 easy examples in action, because you can line up the cups and see a full gradient.

How to turn this into a science fair project

If you want more than just a pretty row of cups, you can:

• Create a color chart: Start with known substances (like vinegar and baking soda) and label the colors. Compare your chart to a standard pH scale from a chemistry textbook or a reputable site such as the U.S. Geological Survey’s pH resources (https://www.usgs.gov/special-topics/water-science-school/science/ph-and-water).
• Measure pH: If you have access to pH strips or a digital pH meter, record the actual pH numbers and match them to your cabbage colors.
• Test natural waters: Compare rainwater, tap water, bottled water, and water from a local stream or pond (with adult supervision and proper hygiene).

In your report, you can say that cabbage juice is one of the best examples of homemade pH indicator because it covers a wide pH range and shows multiple colors, not just one.

Bright Yellow Science: Turmeric as an Example of Homemade pH Indicator

If you like bold colors, turmeric is your friend. This yellow spice from your kitchen cabinet is another excellent example of homemade pH indicator, but it behaves differently than cabbage.

Why turmeric works

Turmeric contains a compound called curcumin. Curcumin is sensitive to bases, which means it changes color when it meets alkaline substances. In neutral or acidic solutions, it stays yellow. In basic solutions, it shifts toward reddish-brown or orange.

Curcumin is widely studied in chemistry and medical research; if you’re curious about its health-related research, the National Institutes of Health has summaries of curcumin studies (https://www.ncbi.nlm.nih.gov/books/NBK92752/), though that’s beyond the scope of a school project.

Making a turmeric indicator solution

You can use either ground turmeric or turmeric tablets (crushed). Ground spice from the grocery store works fine.

• Stir 1 teaspoon of ground turmeric into 1/2 cup of rubbing alcohol or warm water.
• Mix well. If you use alcohol, the color tends to be more intense, but water is safer for younger students.
• Let the mixture sit for a few minutes.
• Optionally strain out the solid bits with a coffee filter, or just use it as a suspension.

You’ll get a bright yellow liquid that’s ready to test.

Testing real examples of household bases

Turmeric is not very sensitive to acids—it mostly stays yellow. It shines when you test bases. Some real examples to try:

• Baking soda solution
• Washing soda solution (if available, and with adult supervision)
• Liquid soap or laundry detergent diluted in water
• Household ammonia diluted heavily in water (only with an adult and good ventilation)

When turmeric meets a base, the yellow color usually turns orange, brownish, or even reddish. This gives you one of the clearest examples of homemade pH indicator: 3 easy examples for detecting bases.

Turning turmeric into indicator paper

For a more advanced twist, you can create your own “pH paper”:

• Dip strips of white coffee filter or plain paper towel into your turmeric solution.
• Lay them flat to dry completely.
• Once dry, touch the strips to drops of your test liquids.

Acids and neutral solutions will keep the strip yellow. Bases will turn the strip orange-brown. You can compare this to commercial pH paper and describe the similarities and differences in your science fair board.

This gives you one of the best examples of homemade pH indicator that behaves like lab test strips.

Flower Power: Hibiscus Tea as a Colorful Example of Homemade pH Indicator

For the third member of our trio, hibiscus tea is a beautiful example of homemade pH indicator that’s easy to find in most grocery stores.

Why hibiscus works

Like red cabbage, hibiscus flowers contain anthocyanins. When you brew hibiscus tea, those pigments dissolve into the water, creating a deep red or magenta color. These pigments respond to acids and bases with noticeable color shifts.

Making hibiscus indicator

You can use hibiscus tea bags or dried hibiscus petals sold for making tea.

• Steep 1–2 hibiscus tea bags in 1 cup of hot water for 5–10 minutes.
• Let the tea cool to room temperature.
• Remove the tea bags. The liquid should be a rich red or pink.

That’s it—you now have a hibiscus indicator solution.

Real examples to test with hibiscus

Hibiscus tends to:

• Turn brighter red or pink in acidic solutions (like vinegar or lemon juice).
• Shift toward purple or bluish tones in neutral to mildly basic solutions.

Try these real examples:

• Vinegar
• Lemon or lime juice
• Carbonated water
• Baking soda solution
• Weak soap solution
• Tap water

You’ll notice that hibiscus doesn’t always show as wide a range of colors as red cabbage, but it still gives clear evidence of acidity versus mild basicity.

Comparing the 3 easy examples

Now that you’ve seen all three, you can compare these examples of homemade pH indicator: 3 easy examples in a table or chart:

• Red cabbage: Multiple colors across a wide pH range (red → purple → blue → green → yellowish).
• Turmeric: Strong yellow that turns orange-brown only in bases.
• Hibiscus: Red/pink in acids, purple-ish in less acidic or slightly basic solutions.

This comparison is great for a science fair conclusion section where you explain which indicator you think works best and why.

More Real Examples: Other Homemade pH Indicator Ideas

If you want to go beyond the classic three, there are several other examples of homemade pH indicator you can mention or test briefly:

• Blueberry or blackberry juice: Similar anthocyanin behavior to red cabbage, but sometimes less dramatic.
• Purple grape juice: Can show subtle shifts from purple to red or bluish tones.
• Beet juice: Not as sensitive, but may show slight color changes.
• Red onion skins: Boiling the skins in water can produce another anthocyanin-rich indicator.
• Some red or purple flower petals (like pansies or purple morning glories): With adult help, you can soak the petals in warm water to extract pigments.

These are great to list in your background research section as additional examples include many natural plant pigments that respond to pH.

How to Turn These 3 Easy Examples into a Strong Science Fair Project

To move from “fun experiment” to “solid project,” you’ll want a clear question, a hypothesis, and data.

Here are a few project ideas using these examples of homemade pH indicator: 3 easy examples:

Project idea 1: Which homemade pH indicator is most sensitive?

• Question: Which indicator (red cabbage, turmeric, or hibiscus) shows the biggest and most useful color changes over a range of pH values?
• Method: Test each indicator with the same set of liquids: vinegar, lemon juice, soda, water, milk, baking soda solution, and soap solution.
• Data: Take notes on color changes, or use a color chart. If you can borrow a pH meter from school, record pH values and match them to colors.

Project idea 2: Can homemade indicators estimate pH accurately?

• Question: How close are homemade indicators to actual pH values measured with a meter or commercial strips?
• Method: For each indicator, match the observed color to a pH number from a chart. Then compare your estimate to the measured pH.
• Data: Create a table with columns for “Sample,” “Indicator Color,” “Estimated pH,” and “Measured pH.”

The U.S. Environmental Protection Agency and USGS have educational resources on pH of natural waters that you can reference in your background research, such as the USGS page on pH and water (https://www.usgs.gov/special-topics/water-science-school/science/ph-and-water).

Project idea 3: Does temperature affect homemade pH indicators?

• Question: Do color changes from your indicators look different at cold, room temperature, and warm conditions?
• Method: Prepare three identical sets of samples, but keep one set cold (in the fridge), one at room temperature, and one slightly warm (around 90–100°F, not hot enough to burn). Add your indicators and compare colors.

You can discuss in your conclusion how stable these examples of homemade pH indicator: 3 easy examples are under different conditions.

Safety, Accuracy, and Real-World Context

Even though these are homemade experiments, treat them like real chemistry.

• Wear eye protection if you’re handling anything stronger than vinegar.
• Don’t taste test liquids once they’ve been mixed with indicators.
• Label all cups clearly.
• Dispose of solutions down the sink with plenty of water, unless you used a stronger chemical (follow label instructions).

For background info about acids, bases, and pH in biology and health, you can look at educational content from places like the National Library of Medicine (https://medlineplus.gov/ency/article/001181.htm) or university chemistry departments. These sources help you tie your examples of homemade pH indicator to real-world topics like stomach acid, blood pH, and environmental science.

FAQ About Homemade pH Indicators

What are the best examples of homemade pH indicator for a school project?

Some of the best examples of homemade pH indicator for school are red cabbage juice, turmeric solution, and hibiscus tea. Together, these 3 easy examples cover acids and bases with clear, visible color changes and use ingredients many families already have.

Can you give another example of a natural pH indicator besides cabbage?

Yes. A good example of a natural pH indicator is blueberry or blackberry juice. These fruits contain anthocyanins, similar to red cabbage, and can shift color when mixed with acidic or basic solutions.

Are homemade pH indicators accurate enough for real science?

They’re excellent for showing patterns—acid versus base and relative strength—but they’re not as precise as calibrated pH meters or high-quality pH strips. For a science fair, you can use them to estimate pH and then compare your estimates to measurements from a meter or strips.

Which of the 3 easy examples works best with younger kids?

Turmeric and red cabbage are usually the best examples for younger students. Turmeric is very simple—yellow turns orange-brown with bases—and cabbage gives dramatic color changes with safe household acids and bases like vinegar and baking soda.

Can I store these examples of homemade pH indicator for later use?

Yes, but not forever. Red cabbage and hibiscus indicators can be kept in a sealed container in the refrigerator for a few days. Turmeric solutions last a bit longer, especially if made with alcohol instead of water. Always label containers and throw them out if they start to smell bad or grow mold.

By the time you try these examples of homemade pH indicator: 3 easy examples, you’ll see that chemistry isn’t just something that happens in a lab. It’s happening quietly in your kitchen, your garden, and your grocery store—just waiting for you to shine a light (or in this case, a color change) on it.