Why Cauliflower Turns Purple
Genetically, many cauliflowers tend toward purple, red, or blue pigments.
Anthocyanin is the same pigment found in red cabbage.
Sun exposure exaggerates its effect on the developing cauliflower head.
The Spruce / K. Dave
Ways to Prevent a Purple Tinge
Cauliflower is usually ready to harvest within 60 days.
It needs daytime temps of between 70 to 85 Fahrenheit to avoid turning purple.
Because if you plant too early, a late seasonfrost can kill young cauliflower.
The Spruce / K. Dave
Also, low soil fertility can cause white cauliflower to turn purplish.
Cauliflower grows best in well-drained yet moisture-retentive, fertile soil with a pH of 6 to 7.
Use a pH probe to test the pH level.
To ensure you have a fertile soil, enrich the soil with compost when planting.
If you use a compost rich inorganic matteryou will not need to fertilize.
To blanch the cauliflower, draw the surrounding leaves up and around the head of the cauliflower.
When to Blanch
Start checking your plants about 30 days aftertransplantingthem into the garden.
When you see a cauliflower curd about the size of an egg, it is time to blanch.
Is Purple Cauliflower Safe to Eat?
If your cauliflower has already turned purple on the edges, don’t despair.
Its appearance may look unappetizing, but a bit of vinegar added to the water minimizes the color change.
Some cooks prefer to use purple cauliflower when composing dishes because it gives plates more visual interest.
Discard cauliflower with disease-like blemishes, meaning it looks brownish, blackish, mushy, or foul-smelling.
Other popularpurple-colored varietiesare Sicilian Violet, Violet Queen, Rambo Purple, and Purple Cape.
Bright sunlight intensifies the color of the curds.
Purple cauliflower is not genetically modified.
Purple cauliflower varieties should be picked after the center leaves covering the head of cauliflower begin to open.
The head should be compact and quite firm.
