Heymatt: I read recently that mushrooms (commercial mushrooms) are grown in hay and straw that has been used in the stalls of horse barns. So, I presume that they are also grown in horse manure, since that substance would naturally be a part of it. I have a mushroom cookbook which states that you should not wash mushrooms because it destroys some of the flavor. Just wipe them off with a damp paper towel, it says. Well, I like mushrooms, especially raw ones in a salad and I have always washed them thoroughly with cold water and sometimes a brush. My question is, are commercial mushrooms contaminated with horse manure? One store that I frequent has mushrooms with a label that says they have been washed. What assurances do we have that even the washed ones are clean? And what of the other ones, the ones that are not washed? Is it likely that we have been ingesting horse manure? — Jack in Sandy Yaygo

You’ll be glad to know that the mushroom industry has anticipated your hysteria and done something about it. Commercially grown mushrooms are pretty clean eatables. The Mushroom Council is ready to pat you on the head and give you a reassuring shoulder-squeeze and lay out the precautionary steps involved in popping ’shrooms out of their commercial growing medium.

Each grower has his own recipe for mushroom medium, but you can bet it includes a lot of straw, maybe taken from the stalls of horses, maybe not. Then add a dollop of manure (horse or chicken is best), then various grain meals, gypsum, and possibly some exotics like molasses or peat moss or wine-making leftovers. Make a big compost pile of this stuff, add some water, toss it around every couple of days, then let the natural bacteria do their thing. The temp inside the pile should rise to 150 to 160 degrees, killing off a whole slew of bad bacteria in a week or two.

Step two is pasteurization, usually done by shooting steam into the mass. After a day or so, we’ve got clean, clean medium. Yeah, there’s still horse poop in it somewhere — hard to tell where, since the medium’s been reduced to a dark, soil-like material — but there are no bad horse-poop bugs. I suspect you’re as worried about the clean poop as you are about the bacteria, but I’m sorry, unless the grower has used a synthetic medium, you gots poop.

Photo by Rick Geary

Food-safety faculties have spent many hours testing various ’shroom-growing recipes, checking bacteria levels on the final product, so the procedure is trustworthy. And there’s never been a reported illness due to mushroom-growing medium. You’re unlikely to be the first. So, take home your stash, leave it in the container (making sure there are plenty of air holes) or put your loose mushrooms in a brown paper bag (not plastic!) and put them in the fridge. On cooking day, dust off any loose medium (check under the cap). Give ’em a quick rinse, then pat them dry if it makes you feel safer. And there you have it. Nontoxic, non-gross-out omelet filling.

I have to congratulate you at not being so horrified by mushrooms that you peel them. Some people actually peel mushrooms. Mushrooms don’t have skins. What do they think they’re removing?

Heymatt: For the past couple of days I’ve been saying a phrase that I don’t quite understand. The phrase is “jeez Louise.” Where did it come from, and who in the world is Louise in the first place? Help. — TR, via email

Louise is one of Ma Alice’s cousins. Jeez Louise is somebody else, though. Your Louise is one of thousands of exasperated oaths glossed over so it isn’t blasphemous. “Jeez” is short for “Jesus” in lots of expressions. Like, “jeez-o-Pete,” a favorite of Grandma Alice and maybe Jeez Louise’s boyfriend. Pete also stands in for God in “for Pete’s sake!” Criminy, Judas priest, and Jimminy Christmas are also part of the pack of “Jesus Christ” euphemisms. “Heck” was somebody’s bright idea for “hell.” “Gosh,” “gad,” and “golly” substitute for “God.” That makes “Good golly Miss Molly” a distant cousin of “Jeez Louise.”

Truth be told, since these are spoken expressions, written rarely and always long after the expression has entered common speech, it’s hard for the word guys to pin down an origin. As for Louise, the only reason she’s there is probably because she rhymes with “Jeez.” It’s one of mankind’s quirks to be attracted to expressions that rhyme or expressions with words that begin with the same letter.