Shuck the corn by pulling back the husks and removing the silky strands. Rinse and pat dry. Lay each ear flat on the cutting board and use a sharp knife to slice the kernels off the cob, rotating to keep a flat surface. Collect the corn kernels in a large mixing bowl.
Rinse the jalapeños and dry them. Cut off the stem end, slice in half lengthwise, and remove the white membrane and seeds with a spoon for a milder result. Finely mince the jalapeño flesh into small pieces (about ⅛-inch or 3mm). Wash your hands thoroughly after handling.
Peel the red onion, cut in half through the root end, and finely dice to about ¾ cup (115g). Wash the red bell pepper, remove the stem, seeds, and white pith, and finely dice to about ¾ cup (115g). Peel and mince the garlic as finely as possible.
Rinse the cilantro, shake dry, and pat gently with a towel. Gather the leaves and tender upper stems, discarding the thick lower stems. Roughly chop until you have about ½ cup (20g).
Roll each lime firmly on the counter before cutting to release more juice. Cut in half and juice using a citrus juicer or reamer until you have 3 tablespoons (45ml). Strain to remove seeds if needed.
Add the corn kernels, diced red onion, diced red bell pepper, minced jalapeño, minced garlic, and chopped cilantro to the large mixing bowl. Pour the fresh lime juice over the top and season with salt and pepper. Gently stir everything together until evenly coated and combined.
Taste the salsa and adjust the seasoning as needed. Add more lime juice for brightness, more salt if it tastes flat, or additional jalapeño for more heat. If it's too spicy, balance it with a tiny pinch of sugar.
Cover the bowl tightly or transfer to an airtight container and refrigerate for at least 20 to 30 minutes before serving. This allows the flavors to meld together. Give the salsa a gentle stir and taste again before serving.