Rarely does a week pass these days without another food scare or outbreak of contamination in our modern industrialized food system. This year alone we’ve had a beef recall (thanks to the documented slaughter of cattle too sick or weak to walk), E. coli contamination of lettuce, and salmonella outbreaks linked to melons and dry cereal. Most recently, tomatoes contaminated with a rare strain of salmonella (Salmonella saintpaul) have turned up in 17 states. While the first case was detected in April, the outbreak is only now making headlines, and many stores and restaurants have pulled raw tomatoes from their shelves and menus.

Until the salmonella tomato outbreak is contained, the U.S. Food and Drug Administration recommends that consumers avoid raw plum, Roma, and red round slicing tomatoes, and limit their tomato consumption to cherry tomatoes, grape tomatoes, tomatoes grown at home, and any tomato sold with the vine still attached– a criteria I’ll investigate momentarily. If you want to be sure to avoid contaminated tomatoes, of course, you’ll have to avoid fresh salsa, salads, and other store- or restaurant-purchased raw tomato products as well, unless you know what kinds of tomatoes went into it.

Other than naming the states, regions, and countries that the FDA has ruled are not associated with the outbreak’s source– see www.fda.gov/oc/opacom/hottopics/tomatoes.html– the agency doesn’t seem to know anything about where the salmonella is coming from.

But the FDA’s recommendation that tomatoes of any kind are OK, so long as they have a portion of vine still attached, offers a clue into what might be going on.

Assuming the skin isn’t broken, the stem spot on top presents the only entrance into a grown tomato that salmonella can access (salmonella could also enter the tomato if it were present on the flower, but if that were the case here, tomatoes with stems attached would be affected by the current outbreak). Thus, the contamination was likely spread during the processing of these tomatoes, and I suspect the FDA is searching for a tomato-processing plant where tomatoes are being washed with salmonella-contaminated water, which is entering the tomatoes through the stem spots.

Even if my salmonella-tainted wash water hypothesis is wrong, it’s possible that the existence of a stem indicates that the tomato couldn’t have passed through certain large-scale, assembly-line, tomato-processing operations suspected by the FDA of being to blame. However you slice it, the stem signifies less processing. And in this case, less processing appears to mean a safer tomato.

You may not hear this from the FDA, but I think you’d be fine buying any kind of tomato directly from a farmer. The act of buying locally grown produce at the farmers market is sometimes branded as “elitist” by those who consider it their god-given right to have dirt-cheap food, as conventional wisdom holds that local, sustainably grown, heirloom, and other such hippy-dippy foods tend to be more expensive than store-bought produce. But now that prices for distantly grown factory-farmed foods are rising along with energy prices, farmers market prices soon may become competitive with supermarket prices.

Meanwhile, bucking the trend of rising commodity food prices, the price of bacon is dropping– and this is no coincidence. On June 5, pork belly futures fell nearly 20 percent on traders’ worries that the salmonella tomato scare might reduce consumer demand this summer– at home and at restaurants– for bacon, lettuce, and tomato sandwiches.

“Realistically, the idea that people are going to be wary of buying tomatoes can’t have been viewed as a favorable development by [pork] belly traders,” said Dan Vaught, Wachovia Securities’ livestock analyst, according to Reuters.

While we’re on the subject of this wonderful sandwich, a few notes on the BLT are in order.

First of all, there should be onions on it. Call it the BLOT, if you wish, but please don’t hold the onions. Also, the bread should be toasted– otherwise the juice of the tomatoes, combined with the penetrating action of the mayo, will quickly turn your bread to mush.

The arrangement of the BLT’s contents is crucial. The tomato must have direct contact with the mayo, and the bacon must have contact with the tomato. And while commodity bacon is cheap these days, I would still encourage you to pay the extra money and make your BLT with locally grown, elitist bacon.

Meanwhile, if you can get your hands on some green tomatoes, consider frying them (the heat will kill salmonella) and making a fried green tomato BLT.

Sprinkle your green tomato slices with salt and pepper. Place some flour in a shallow bowl. Mix equal parts flour with cornmeal in another shallow bowl. Working with one green tomato slice at a time, coat with flour, then dip in beaten egg, then toss in the flour-cornmeal mixture, and transfer to a skillet in which 1/4-inch of olive oil is heating over medium-high heat, and fry coated tomato slices until golden brown– about two minutes per side. Remove with slotted spoon and season to taste with salt and pepper.

For a nice touch that’s in keeping with the green theme of those fried green tomatoes, consider blending the mayo for your fried green tomato BLT with a handful of fresh basil leaves and a touch of mustard, lemon juice, and chopped garlic. Ideally you’d do this ahead of time and leave the green mayo in the fridge, covered, until needed.

If the green theme isn’t your scene, and you can’t find tomatoes with stems, and the FDA stays mum about where the salmonella contamination is coming from, then I recommend you hold off on that BLT until the tomatoes in your backyard or local farmers market come in. But if this local-schmokel food elitism is too much for your populist sensibilities, feel free to choke down your BLT, with or without onions, with the salmonella-laced tomato of your choice. If the supermarkets still stock them, they might be on sale.