Gherkins are similar to cucumbers, and both fruits are perfect for pickling. Gherkins, however, should be pickled while still young and no more than three inches long, as they tend to become sour and spiny as they mature. Pickling gherkins is relatively simple, though it may take some trial and error to find a blend of spices and the right length of pickling time to suit your tastes. Pickled gherkins may be sweet, sour or spicy based on the ingredients used.
Rinse the raw gherkins and allow them to dry. Sprinkle salt on them liberally and let them sit for 24 hours. Rinse and dry them again.
Pack the gherkins tightly into Mason jars or similar containers. The containers do not have to be airtight, as oxygen aids in the fermentation process required for pickling.
Measure out enough white wine vinegar to completely saturate the gherkins in the jars. Pour the vinegar into a pan and bring to a boil.
Add the mustard seeds, salt, peppercorn, garlic and coriander to the vinegar. The amount you use will vary depending on your taste. For sweet gherkins, add a generous amount of white sugar. If you like your pickles spicy, add minced jalapeño peppers.
Bring the vinegar and spice mixture to a boil. Lower the heat and let the mixture simmer for about 10 minutes.
Pour the vinegar mixture over the gherkins in the jar, making sure to completely saturate the gherkins. This should be done when the mixture is still warm.
Seal the jars with lids or pieces of cloth fastened with a rubber band. Most recipes suggest allowing six weeks for fermentation but, as with the spice mixture, you will have to decide what best suits your taste.
Shorter fermentation periods will result in more crisp pickles with a taste closer to the original fruit. Allowing pickles to ferment for six weeks or more will result in slightly soggier pickles that are more sour (or sweet or spicy, depending on the spices).