How, when I’m steaming broccoli, does the broccoli get more green and turn the water green?


Where does all that extra green come from?

In: Biology

My guess is that it is because the broccoli is dehydrated to some extent. When putting in water, the broccoli absorbs the moisture and returns to its more ‘normal’ shade of green

You’re physically changing the plant by cooking it. Some of those changes involve the parts that have the green bits in them, and it’s that change that makes the green brighter.

Because you’re boiling it in water, some of those bits leak out into the water, the same as what happens when you make tea or coffee. It happens because the hot water is hot, which means it has energy, and because hot water is water, which is good at dissolving things. Energetic dissolving means you get parts of the veggie sucked out into the water. Even when steaming, the steam will condense and make liquid water on the surface of the broccoli, and that water will mix with the rest of the water and steam and carry the green bits with it.

Steaming vegetables makes the surface less reflective and more transparent. Instead of bouncing off, light is more likely to be absorbed by the inside of the broccoli. Less light means a darker appearance. The amount of green pigment isn’t changing.

There are a lot of ways to change the color – others have given some answers.

One other thought – if you’re cooking in water that is more basic, or alkaline, it’ll make the green more vibrant and brighter because it preserved the chlorophyll in the vegetable. Add a few drops of vinegar or lemon to make the water more acidic, it’ll break down the magnesium and cause your green vegetables (not just broccoli..) to become dull and olive drab.

Many red and white vegetables have the opposite effect (brightening in acid, but becoming dull, dingy and gross looking in alkaline.)

Yellow veggies like carrots, bell peppers, pumpkin and corn don’t react either way and can be cooked in either acidic or basic water.

I’m sorry I don’t know the exact science behind it.. I’d have to look it up in my text books.