Choose small, firm cucumbers and wash with cold water. Allow to air dry.
Pack a quart jar with cucumbers, two heads of dill and two cloves of garlic.
Add ΒΌ teaspoon of alum to each jar.
Heat the water, vinegar and salt to a boil.
Pour the boiling mixture over the cucumbers and seal the jars.
Flip the jars upside down, resting them on the sealed lids, for a couple of hours.
Then return to the upright position. They will make a popping noise when the lids have sealed.
Press your finger down in to the middle of each lid. If the lid bounces back up under your finger, the jar has not sealed. If the lid does not bounce, it has sealed.
Wash the jars and write the date on the lids with a Sharpie. The pickles are ready to eat after three months!