1/2 cup soy sauce
1/4 cup apple juice concentrate
3 tablespoons spicy mustard
2 medium sweet red peppers, cut into 1-inch pieces
1 medium green pepper, cut into 1-inch pieces
1 medium yellow summer squash, cut into 1/2-inch cubes
1 package (19 ounces) Cheddar Brats
In a large resealable plastic bag, combine the soy sauce, apple juice concentrate and mustard; add vegetables. Seal bag; refrigerate for one hour.
Place brats in large sauce pan and add enough water to cover brats. Parboil on med-high heat for about 10 minutes.
Remove from pan and allow to cool slightly. Slice each brat into 5 equal pieces and thread onto metal or soaked wooden skewers, alternating with the vegetables.
Brush with reserved marinade and grill over medium heat until vegetables are tender and brats are golden brown, turning and basting frequently with reserved marinade. Serve immediately.