Last year I cut up some chunks of cucumber and put them into a gallon pickle jar in the fridge that was half full of store bought pickles. I didn't eat them right away, then thought maybe I should never eat them since they had been in there so long.

Its been a year, the cucumber chunks are big, like 2-3 inches thick, not slices. Should I eat them or throw them out? I didn't can them, just peeled and put in the pickle jar with the other pickles in the pickle brine. Is it safe, could the brine have gotten into the middle of those big chunks and preserved it?

Information on lacto-fermented pickles gives recipes similar to what I did, saying to put cukes in cold water with salt, with or even without whey. Is lacto-fermentation not considered safe?

Fermented foods such as sauerkraut and fermented pickles are preserved with lactic acid. Other fresh packed or quick-packed pickled foods (such as store-bought pickles) are made with vinegar and are NOT fermented.

Lacto-fermentation is safe when properly done but it is not the same thing as what you did. Fermented pickles are made with very specific amounts of salt and water and the interaction of the 2 creates lactic acid. It is that lactic acid that makes them safe and little or no vinegar is involved.

You can find detailed information about the 3 different types of pickles - fermented, brined, and quick-pack - at NCHFP.

Store bought pickles are fresh-packed pickles and the primary ingredients of them is vinegar. The store-bought pickles are made with a specific amount of vinegar, measured for the specific amount of pickles in the recipe and for the size and shape of the cucumber chunks in that recipe. As those pickles sit in that vinegar mix the water in them is exchanged for the vinegar and the liquid in the jars is diluted/weakened. That is why they have an expiration date and must be kept refrigerated.

Now when you add fresh cucumbers, regardless of the shape, to that already weakened brine the water in those new cucumbers further dilutes the brine so what you end up with is low-acid cucumbers in a very watered down vinegar. Vinegar that is now so diluted as to be considered unable to prevent bacterial growth and so is unsafe.

OK?

Dave

PS: if interested you'll find several previous discussions here on why using used brine is not considered safe for pickles.

What if I had added more vinegar and salt at the time I put the cukes in, would it have fermented and been safe then?