Butterfly pea flowers (hoa đậu biếc) is a climbing vine. I am documenting how we grow and use our butterfly pea flowers. There is a single-layer petal variety that resembles a butterfly when in full bloom. I have the double-petal layers so it doesn’t look anything like a butterfly. The blue flowers can be extracted to make a natural blue food coloring.
The butterfly pea vine likes to be planted in well drained soil and partial sun. One year, I planted my vine against my neighbor’s fence in the front next to my starfruit tree. It covered the fence beautifully within two months. My neighbor likes looking out her patio to see the beautiful flowers blooming too. It grew so fast that it started strangling my starfruit tree branches. So I ended up taking the entire vine out by late fall. I don’t know if it will survive the climate zone 9B here or not. The following year, I planted the vine in the backyard in hope it would be a nice shade around my patio. That’s when I learned the plant doesn’t like a lot of water and too much direct sunlight on it. It’s been three months and it’s not covering the trellis like it did with the neighbor’s fence last year.
To make a natural blue food coloring, collect the blue pea flowers, simmer it in water until the blue food coloring is a concentrated deep blue color like shown in the picture. Pour the dark blue water through a mesh to filter the liquid out. Let cool and store it in air tight containers. I use small containers (2 or 4-ounces) to store the natural blue food coloring and freeze it.
We can use the flowers to make a nice blue, purple, or pink colored butterfly pea flower tea or limeade/lemonade tea drink.
My kids like me to use the blue extract to make some Vietnamese coconut agar agar jello. It gives it a nice elegant look. (I’ll post the link to my pictorial recipe when I publish it.)
The extract from the flowers can be used to make blue sticky rice. I will update this post with a link sometime.