How to Open a Stubborn Jar
These are some tips I use, others I found on the Internet, for getting a stubborn jar lid off.
1. The first thing I try is to use something to get a better grip. I have this piece of drawer and shelf liner that I got at the Dollar store which works for me. Other suggestions on the Internet is to put on a rubber glove, use a piece of plastic wrap, even put a rubber band around the lid.
2. Tap the lid on top of the jar with the handle of a butter knife, but aim for the edges. Another suggestion is a wooden spoon. This should help loosen the seal.
3. Step three, if you are still having trouble, is to run hot water from the tap on the lid. It should help to expand the metal of the lid.
4. Slap Tactic. Tilt the jar downward at a 45-degree angle with your non-dominant hand. Aggressively slap the bottom of the jar with the center of your palm and listen for a pop. I have not tried this technique.
5. Another hot water technique is to place the jar, upside down, in a bowl of hot water. Similar to step 3.
6. Last is to use a dinner spoon or knife and place it in the crack between the lid and the glass and consistently push up (even twist) in an attempt to break the seal. One site even said you could use a flat-head screwdiver. You may need to work your way around the lid.
One time when having a hard time getting the lid off of a sauerkraut jar, I was soaking the jar in hot as in Step 5, then read about using the screwdiver as in Step 6. I took the jar out of the water, used the screwdriver on it, and the seal popped open allowing me to open the jar.