In a large pot over medium high heat, add the water, vinegar, sugar, salt. and mustard to a boil. Lower the heat to low and keep simmering.
In 4 separate sterilized jars add sliced cucumbers till about 1 inch of headroom. Pack the cucumbers down using the back end of a serving spoon.
Add the coriander, peppercorn, dill seed, peppers, and garlic to each jar.
Using a sterilized funnel, pour the brine liquid into each jar till about 1 inch of head room remains. Screw the tops onto the jars.
Add the jars to your canner and process according to directions with your canner.
Carefully remove the jars using jar tongs to a towel and allow to cool before putting in storage.