Butterfly pea flower tea changes color with lemon

The vibrant blue hue of butterfly pea flower tea is a result of anthocyanins, a type of flavonoid pigment found in the flowers. These pigments are pH-sensitive, meaning their color can change depending on the acidity or alkalinity of the liquid they are in. When you add lemon juice, which is acidic due to the presence of citric acid, the pH of the tea decreases. This shift in pH causes the anthocyanins to undergo a chemical reaction, altering their molecular structure and, consequently, their light absorption properties. As a result, the blue color transforms into shades of purple and pink. The more lemon juice you add, the more acidic the tea becomes, and the more pronounced the color change will be, moving towards a vibrant fuchsia or magenta.

To observe this fascinating color change, you'll need a few simple ingredients and tools.

First, gather your butterfly pea flowers. You can purchase dried butterfly pea flowers online or at specialty tea shops. The amount you need will depend on how much tea you want to make, but a good starting point is about 1-2 tablespoons of dried flowers per cup of water.

Next, you'll need water. Use fresh, cold water for the best flavor.

Then, prepare your lemon. A slice or two of fresh lemon, or a small amount of lemon juice, will suffice. The amount of lemon juice will directly impact the intensity of the color change.

Finally, you'll need a kettle or a pot to heat the water, and a mug or a clear glass to brew and observe your tea. A clear glass is particularly recommended to fully appreciate the visual transformation.

The process is straightforward.

1. Heat your water to a near boil. For optimal extraction of the pigments, aim for a temperature between 90-95 degrees Celsius (194-203 degrees Fahrenheit). Avoid boiling the water vigorously, as this can sometimes lead to a duller color.

2. Place the dried butterfly pea flowers into your mug or teapot.

3. Pour the hot water over the flowers.

4. Let the tea steep for about 5-7 minutes. You'll notice the water gradually turning a deep, beautiful blue. The longer you steep, the more intense the blue will be.

5. Strain out the flowers. You can use a fine-mesh sieve for this.

6. Now comes the magic. Take your lemon slice or squeeze some lemon juice into the blue tea.

7. Watch as the color begins to shift. Initially, you might see streaks of purple appear where the lemon juice makes contact. As you stir, the entire cup of tea will transform into a lovely shade of purple or pink.

For a more dramatic effect, you can experiment with different amounts of lemon juice. A small squeeze will yield a purple hue, while adding more juice will push the color towards a vibrant pink. You can even prepare two cups of blue tea and add varying amounts of lemon to each to see the spectrum of colors.

The science behind this color change is a wonderful illustration of how chemistry can create beautiful and engaging experiences. The anthocyanins in butterfly pea flowers are part of a larger family of compounds called flavonoids, which are common in many fruits and vegetables and are responsible for a wide range of colors, from the red of apples to the purple of blueberries.