Why peel tomatoes when making salsa

If you boil them for more than a few seconds, you'll start cooking the tomato, which can make it harder to work with -- you effectively want to cook just the bit under the skin, which only takes a few seconds.

I work with a paring knife and a set of spring loaded tongs (but you could use a spider or strainer).

• start a pot of water boiling
• cut an X in the bottom of the tomatoes
• once the pot of water is boiling, reduce to a simmer
• drop a tomato in the water for about 5 seconds.
• let the tomato cool for a few seconds. (you could use cold water, I just wait).
• hold the tomato in your off (non-dominant) hand
• hold the paring knife in your right, but not for cutting ... grab it like you'd hold a paint brush, with the tip of the knife blade near the end of your thumb, and your thumb against the flat side of the blade, and the sharp side facing towards your body. (this is one of those cases where pictures would help).
• slide the knife under one of the 4 flaps left from the X, grab the skin with your thumb and pull.
• repeat for the other 3 flaps.
• if there's any skin left, repeat until the tomato is clean.

If the skin was still sticking, increase the time for a second or two until you find the right time. If the tomato was getting difficult to hold, decrease the time.

Once you find the right time to cook the tomatoes for, I cook about 3 romas or two larger globe tomatoes at a time -- while one batch is cooling, I peel the previous batch, dip another set, repeat, and you'll have a batch done in no time.

When tomatoes are cooked (which I assume you plan on doing for canning or after freezing) the skins become tough and usually detach from the tomato. Since you usually don't mind this, you shouldn't mind it with canned tomatoes either, but many people do - even when pureed the texture is different.

When freezing you can freeze whole and the skin should come off easily when thawed.

One way to get around the texture issue would be to puree the tomatoes and then force them through a food mill, which will help to remove tough bits - do this either before canning or after freezing.