In a large bowl, combine the corn, red pepper, onion, and poblano pepper. Set aside.
In a large pot, combine the vinegar, sugar, mustard seed, cumin, coriander seed, celery seed, crushed red pepper, salt, and black pepper. Bring to a boil over medium-high heat, then add the corn mixture. Return to a boil and then reduce heat to low. Simmer uncovered for 15 minutes. Spoon off any accumulated foam.
Whisk together the water and cornstarch and then stir it into the corn mixture. Turn heat up to medium and cook for 5 minutes, or until mixture starts to thicken, stirring occasionally.
Ladle into 4 pint or 8 half-pint sterilized canning jars. Cover jars with lids and screw on the bands. Let cool to room temperature and then refrigerate for up to 3 months.
