Blanching prevents the enzyme action that softens and discolors vegetables from taking place, exactly what you need to preserve the fresh, vibrant colors of juicy bell peppers. Typically, hot peppers don't need blanching because they have a large amount of capsicum, the chemical responsible for their heat, which naturally preserves them. Blanching kills any residual bacteria left on the peppers after rinsing, so you want to blanch before you freeze, can or pickle them. Blanching also helps peppers cook evenly in the oven, so you definitely want to blanch bells before stuffing them.
Rinse the peppers and slice them in half lengthwise. Trim off the stems and discard the seeds. Slice the peppers into rings or strips, whichever is desired.
If you are blanching the peppers to stuff later, cut off the stems and remove the seeds only.
Bring a pot of water to a boil and fill a large bowl or food container 3/4 full of ice. Top the ice off with water.
Place the peppers in the boiling water. If the whole peppers float, push them down with the tongs. Blanch whole peppers for three minutes, halved peppers for three minutes and rings for two minutes.
Lift the peppers from the boiling water with tongs and place them in the bowl of ice water. Chill the peppers for as longs as you blanched them. Refill with ice and water as needed when blanching in batches.
Remove the peppers and let them air dry on paper towels.