What It Means When Deli Meat Feels Slimy (It's Not Spoiled)

Slime holds firm a place in our food landscape. We may wish to reject that notion, but facts are facts. We meet slime head-on in virtually every aisle of the supermarket: Fresh produce gets slimy, cooked salmon sprouts a white slime, and Lean Finely Textured Beef — also known as "pink slime" — remains not only available to consume, but was also rebranded as ground beef by the USDA in 2019 (so, you know, eat up). 

While slime on food as visually unappetizing, its presence is not always a sign of Lovecraftian corruption. The slime on white salmon, for example, is albumin, a harmless protein that develops when the fish is cooked. This is also case of deli meat, which may sports a ominous-looking layer of slime after spending time in your fridge. That deli meat slime, though arguably one of the most unpleasant phrases you'll encounter today, is simply a by-product of its creation.

The slime on deli meat is due to additives that are intended to make it more appealing to the customer. These range from dextrose (sugar) and sodium nitrate to carrageenan, which thickens meat, and are injected during processing. As butcher and Rastelli Foods Group president Ray Rastelli, Jr., explains, "The whole, unsliced initial product literally encases these added ingredients, so once opened and sliced, the dissolved ingredients that were injected into the meat originally now have a mode to leak out of the product." You're thinking it, so just say it out loud: Ick.

There's another equally unappealing reason why your deli meat has been slimed: Bacteria, and by which, we meant not the plague-carrying kind, but rather, the (largely) benevolent strain lactobacillus, which is found in fermented foods like yogurt and kimchi, as well as certain supplements. Lactobacillus can come into contact with meat during processing, and feeds on the sugar additives in deli meat. 

This consumption turns the sugar into lactic acid, and the end result of that transformation is slime. Gross? Definitely. But food gone bad? "Strong off-odors, not slime, indicate spoilage," Brian Nummer, a food safety professor at Utah State University, explained to Men's Health in 2011.

Those odors are also a by-product of lactobacillus. The fermentation process that produces lactic acid can also generate a variety of gasses, such as carbon dioxide, and acids which create the unpleasant odors and colors that indicate impending spoilage. Storage, time, and temperature issues aid in this grisly change, which is why deli meat should always be kept in airtight containers and at 40 degrees Fahrenheit or below, and consumed or disposed of within three to five days of purchase.

So while nothing that you would want to actively cultivate, slime is not your cold cuts' enemy. Chalk that up to modern food processing. It's the odor and discoloration that tell you it's time to part ways with that half-pound of mesquite smoked turkey breast.