Combine the salt, sugar, juniper berries, peppercorns, cloves, thyme and bay leaves with 1 gallon water in a large stockpot. Bring to a boil over high heat and stir until the salt and sugar are dissolved, about 3 minutes. Remove from the heat and allow to cool completely, about an hour.
Pour the brine over the brisket, weighting the brisket down with a heavy plate to ensure it's completely submerged. Cover, and transfer to the refrigerator to brine for 1 week.
Remove the brisket from the brine and discard the brine. Rinse the brisket well in cold water.