This has probably come up before, but i'm probably older than most of you and have the prerogative of forgetting or telling old stories over and over
I never got that thing about not cutting lettuce with a knife.
Supposedly it gets brown around the cut edge.
I have never had lettuce brown around a cut edge any more than it browns around a torn edge.
But tearing implies some rougher handling than the smooth cut of a sharp knife.
I think it's one of those old wives' tales, or rather, since most chefs are men, old men's tales.
I've heard two lines of reasoning:
- the "metal knife" explanation - presumably because iron and steel rust, cutting with an iron or steel knife will make the lettuce "rust". I don't know the science of this, but it would mean that there is a chemical reaction with the steel and the lettuce. It seems unlikely, but I'd be curious as to the explanation. And if that is true, then what possible chemical reaction would there be with a stainless steel knife?
- the bruising explanation - presumably cutting with a knife bruises the lettuce. Really? And grasping lettuce in your hands and tearing it doesn't bruise the lettuce? i think it bruises it more, tearing leaving more cells open, torn, more surface area on the cut side than a nice clean cut with a knife, and the holding in the fingers to pull it also would bruise it
What i notice is that lettuce left in the fridge will "rust" around any open edges, whether intentional cuts or tears or just the wear and tear of being shipped and all.
Has anyone tested this? Considering the excessive amount of time it takes to tear lettuce, as opposed to cut it with a good sharp knife, there should be some good evidence.