Can Pickles and Fermented Foods Be Frozen?

Storage conditions for pickles depend on how they were prepared. Salt and acid alone do not make every pickle safe at room temperature. Only pickles canned according to a tested recipe, with an intact sealed lid, are stored in a cool, dark place; follow the storage label on commercial pickles. Refrigerate fully fermented homemade pickles that have not been heat-processed. Freezing can change their texture; choose the storage method specified by the recipe or product label.

The quality that suffers is crunch. The cells of vegetables used for pickling, such as cucumbers, cabbage, peppers, and carrots, are full of water; ice crystals that form during freezing rupture the cell walls. When thawed, water runs out, the vegetables wilt, and what remains is a soft, fibrous piece instead of a pickle that crunches when you bite into it. The crunch does not come back; vinegar, salt, or an ice-water soak cannot repair the damage. The pickles retain their flavor, but their texture no longer serves the purpose of the recipe.

A second kind of loss occurs in live fermented foods. Unheated products such as homemade pickles, sauerkraut, and fermented turnip juice contain microorganisms that remain active; their flavor deepens over time because fermentation continues, even if slowly. Freezing stops this activity, and some of the microorganisms do not survive thawing. The product remains safe but no longer develops; its flavor is fixed at the point when it was frozen, and it does not regain its former liveliness after thawing.

There are a few exceptions that tolerate freezing relatively well, and they share the quality of already being soft or intended for cooking. Roasted and fermented pepper pastes, chopped sauerkraut intended for a cooked dish, and some fermented sauces do not suffer a noticeable loss when frozen, because crunch is not expected in the finished dish. Divide these products into portions, drain them from the brine, and freeze them; pickles frozen with their brine become much more watery when thawed.

The real solution is proper storage, not freezing. An unopened jar of pickles keeps on a cool, dark shelf where the temperature does not fluctuate. Refrigerate an opened jar and keep all the vegetables submerged in the brine; pieces left above the liquid soften and grow mold. Always use a clean, dry fork to remove pickles from the jar; anything introduced into the brine shortens their shelf life, so this is the most effective precaution. If you have made too many pickles, dividing them among smaller jars gives a much better result than freezing them.