Folk Wisdom: not always correct

Piper’s first day of school is today, and last night I was all kinds of anxious about what kind of day she’d have, wanting to send her with the best lunch I could … so when she said she’d like a ham and cheese sandwich, I agreed.

But we had no mayonnaise. Kate finds the stuff abhorrent.

So I whipped up a quick batch of mayo, using Alton Brown’s recipe . It’s basically the same as every other version – egg yolk, lemon juice and vinegar, with which you carefully start an emulsion with a few scant drops of the oil of your choice and then slowly nurture it along, your arm muscles protesting as you whisk with one hand and dribble oil into the bowl with the other, hoping all the while that the bowl doesn’t amble off the counter.

The mayonnaise, my mayonnaise, comes out just fine – tangy and creamy, just like I like it – and I then remember Alton Brown recommending an extra safety step that seemed counter-intuitive at the time: leaving the freshly made mayo out for a couple of hours, because something something the acidity something room temperature. That level of fuzzy recall won’t do, so I go looking for the truth.

Turns out there’s a problem with Brown’s recommendation: it’s not long enough . The acidity from the vinegar and lemon juice will kill salmonella dead … but only if it’s at room temperature for at least 24 hours.

So now, contrary to all the folk wisdom about mayonnaise being something that will kill you if left out at room temperature, I’ve got a jar of garlicky mayo that I am deliberately leaving out for 24 hours. Weird.