We buy the big jar of capers, and we don't refrigerate them, and they seem to last a long time just fine. We follow the same
rule for our capers that we follow for the many, many other items that say "refrigerate after opening" that we store in our
boat temperature cupboard - we ONLY USE A CLEAN UTENSIL TO DIP INTO THE CONTAINER. Mayonaise in the squeeze bottle lasts months without
refrigeration, as to sundried tomatos, mustard, pickles, anchovies in jars, olives, jams and jellies, sauces, salad dressings, etc. But we are pretty fastidious (even the
kids, I think) about using a fresh utensil - PBJ sandwiches require a knife and a spoon, and NO LICKING THE PEANUT BUTTER OR NUTELA OR WHATEVER AND PUTTING BACK INTO THE JAR!
I will agree that after a while, firmness/quality of the product may suffer a bit, but hey, its
boat life. Showers also suffer from not enough
water that is not hot enough, mattresses that are not comfortable enough, roofs that are not quiet enough (or, heaven forbid, leak proof enough) in a pounding rainstorm, etc. That we even get to enjoy our fresh snapper filets in lemon-caper sauce while anchored off a white sand beach in gin clear
water 30 miles from the closest settlement allows me to overlook a slightly less crisp bite in each individual caper berry.
Dang, we gotta get south to enjoy those capers!