The power of sayings and beliefs in the kitchen

In the 3rd millennium (that really is where we are), this kind of idea leaves one reeling, but, well, I suppose (I hope, even) that behind it there's a large measure of what we might call “continuity”: we've been told this when we were very young (or at an age when we were more inclined to believe what others said, especially if they were adults), we took it at face value, then later never gave it another thought, the saying having become an accepted truth.

This belief that “women who are having their periods can't make good mayonnaise” is actually quite widespread. I heard the chimist Hervé This telling a conference that he'd discussed this with a senior schools inspector, a woman who was convinced it was true!

Quite a few wine growers of, let's say, a generation ago, would bar the ladies from going down into the cellar for fear that they'd “spoil” the wine.

So for some, a woman's normal physiological processes can affect food that she is preparing – and that without her even touching it? Must be magic…

Of course, like any man who pays attention to and cares for the woman in his life, I know that this is a time when one can be rather more sensitive, irritable, or a bit tense, so managing tricky operations might be a little more risky, but quite frankly, when it comes to beating eggs or making mayonnaise, it's hardly an issue.

But apart from these medieval (and chauvinistic) sayings about women's periods, there are plenty of other more innocuous sayings that work pretty much the same way: everyone knows that… You know, the sort of phrases that start something like, “You should always cover a pan while it heats, so that it comes to the boil more quickly”, or “You should leave the stone in with the avocado flesh to stop it turning brown”.

And I'm sure that you must know loads of others. I've been wondering just how true they are. And, above all, how can we test them?

With this in mind, a while ago I set up a new category of recipes (not that they are that really) dedicated to such kitchen sayings. The principle is more or less this: I take a saying and I attempt to test by simple means if what we've been told is true or false. Of course, I wouldn't pretend to announce the result as scientific fact. It's just a matter of common sense; the saying says this: OK, let's do it to see if it's true, and let's do precisely the opposite to see if it really doesn't work and therefore if there is any rule we might apply.

As I don't have any sophisticated apparatus to hand, we're in Mr Average's kitchen after all, I make a point of doing it with the most basic of means: a thermometer, scales, etc. I started with a saying that I believed myself: “You should always cover a pan while it heats, so that it comes to the boil more quickly”, a phrase I'd heard many times, even from the mouths of chefs on television.

To test if this was true, I just measured the time a pan of water took to come to the boil, both covered and uncovered. And what a surprise! Covered or not makes no difference (or so little that it's negligible). Yet at the outset I would have bet that that it was true; it seemed to be so obvious.

If we need a maxim or a way of summing this up, it might be, “Don't take any rule or tradition for granted, test it first”.