Enough 6-inch cucumbers, quartered, to fill 8 quart jars (leave any small cucumbers whole)
Mix together vinegar, pickling salt, mustard, brown sugar, alum, and turmeric. Pack cucumbers on end in quart jars. Fill jars with the cold brine and let jars stand, covered, on a shelf for 3 or 4 days. Pour brine off into a large kettle and add additional cucumbers to jars wherever there's space. Heat the brine to boiling and pour over the cucumbers. Cover and process for 5 minutes in a boiling-water bath.