Oktzim, Chapter Two, Mishnah Four
1) All kinds of peels defile and are defiled, and join together.
2) Rabbi Judah says: an onion has three skins: the innermost one whether it is in its entire state or whether it be pierced with holes joins together; the middle one when it is in a whole state joins together, but when it is pierced with holes does not join together; the outermost skin is in either case insusceptible to uncleanness.
Section one: Peels generally protect the fruitthat’s what they’re there for. So they count as part of the fruit, they defile and can be defiled and they join together to add up to the minimal amount.
Section two: Rabbi Judah distinguishes between the different layers of an onion. The inner part is always considered part of the onion. It’s probably edible so why shouldn’t it be. The middle part is part of the onion when it is whole. But if it has holes, meaning it’s not complete, it is not part of the onion. [This is probably the part I always try to keep because I don’t like to waste, but sometimes I can’t peel the outer part without taking this off as well]. The outer peel is not part of the onion because the onion is protected even without it.