A Second Course

Science Experiment

I couldn’t wait to get home and share my tip of the day!!!  Ever wonder why your green beans turn into “olive” beans while cooking? Or your Cauliflower becomes a yellow mush when you boil it?  Well I have the answer to colorful food (no not food coloring) and it all stems from the pigment in these vegetables. Think back to middle school science…

Green = Chlorophyll

Red/Purple = Anthocyanins

White = Flavones

Orange/Yellow = Carotenes

Chlorophyll is destroyed by acid, so adding acid (i.e. lemon, wine or vinegar) and heat will cause it to turn into a pukey green color reminiscent of canned veggies.  So stop squeezing lemon into your cooking liquid! For bright crayon green, just boil your vegetables in salted water uncovered until al dente. Please take note, vegetables are naturally acidic and their acids are released during cooking. So if you boil it covered, the acid will steam within the pot causing your veggies to change color, exactly what we are trying to avoid.*

Red/purple and white vegetables have opposite pigments. Color is enhanced with the addition of an acid. Cauliflower becomes whiter and purple cabbage becomes brighter! So squeeze in just a drop of lemon, vinegar or white wine and watch the colors on your plate explode.

Don’t believe me – try it like we did! You can see our experiment on the plate above (clockwise) starting with the purple cabbage in acid, green beans (sorry there are only two, we got hungry) in salted water, cabbage in alkaline (blue mush), white cauliflower in acid, green beans in acid, cauliflower in alkaline.

Carotenes are not water soluble, so the condition of the water has little effect on the pigments.

And you thought consomme was cool!

*If you are only cooking your green vegetables for a minute or two, it would be okay to steam since there really isn’t enough time for the acid to affect the color. But prolonged cooking/steaming in acid will cause them to turn olive colored.

**Artichokes are considered a white vegetable (the inner stalk is white) so cook with an acid.