(03-17-2012, 02:20 AM)abridgetoofar Wrote: Digging up this old topic because I have discovered the reason behind this, and you are correct, it is a naturally occurring condition of romaine lettuce.
This happens during winter months particularly on romaine lettuces. When temperatures drop below freezing, the "skin" of the lettuce gets damaged from freezing and separates from the lettuce itself, which can then easily be peeled off and seem very much like a type of plastic coating. It's only seen on certain types of lettuces which can withstand the cold temperatures which cause this to happen. There is no substance or coating on the lettuce itself and it is perfectly safe to eat.
I'm not saying that there doesn't exist types of wax and cellulose coatings for protection and shipping, even in organic production, but if you see this on lettuce (romaine particularly) in the winter months, you can safely assume that it is simply skin damaged in a freeze.
Thanks, Austin! Very helpful! I was just about to say, my lettuce doesn't have it! But we didn't get a winter this year so that explains it.
Austin is right. Now that I think about it, last year (when we did get some hard freezes) my greens did take on a different texture sometimes. That was before I knew about this but I seem to remember something like that.