At some point, people noticed that if they placed grape leaves in the crock or brine during fermentation, cucumbers were less likely to soften. Researchers later discovered that grape leaves contain varying amounts of a natural inhibitor that reduces the effect of a softening enzyme found on moldy cucumber blossoms. If you use fresh cucumbers and remove the blossom, there is no reason to add a grape leaf to your fermentation vessel.
So what can help ensure that you make crisp pickles?
Several tricks will help ensure crisp pickles:
Use freshly picked cucumbers.
Cucumbers begin to deteriorate soon after harvest. And cucumbers are susceptible to chill-injury, so storing them in the refrigerator for more than a day or so can result in poor quality pickles.
Carefully clean cucumbers prior to pickling.
Whether making genuine dills in a crock or quick-process pickles, carefully wash cucumbers in clean water, making sure to remove soil that may cling to area around the stem or blossom.
Remove a thin slice (1/16″) from the blossom end of each cucumber prior to pickling.
Enzymes which cause softening are concentrated in the blossom end.
Consider a commercial crisping agent (calcium chloride).
Commercial products, such as Pickle Crisp, which are designed to help cucumbers retain crispness are readily available. Use as directed.