It turns out that the first canned foods where in “hole and cap” cans or “solder dot” cans. To open one of these cans, you would stab a hole into the top with a knife and then pull the the cap off. Obviously, this method isn’t going to work well with today’s cans.
1. Cut Lid Off With Knife
This is the easiest method of opening a can without a can opener. Obviously, you’ve got to be careful that you don’t hurt yourself with the knife. You’ll also end up with a very sharp, jagged edge around the can where you can slice yourself. Pierce the can with the tip of a sharp, pointy knife: You’ll want to use something as a “hammer.” A metal cup or wooden mallet work well. Position the knife upright and then hammer the butt end of the knife gently until the tip pieces through the can. Grip the knife firmly: Choose a position on the blade or handle (depending on the type of knife) so you have good leverage. Rock the knife back and forth: This will slice the lid of the can as you move the blade around the lid.