Step 1 In a heavy saucepan, combine the vinegar, water, salt and sugar over high heat until it comes to a boil. Remove from heat. Place the jalapeños in a large jar or medium glass bowl and pour over the liquid. Weight the jalapeños down so they stay submerged, and set aside until cool. Cover and refrigerate the submerged jalapeños for at least 12 hours to pickle. The jalapeños will keep for up to 2 weeks, covered and refrigerated.