Shirley - the odds are not in your favor when it comes to preserving chopped or pressed garlic or even making garlic oil. If you must do this by the commercially prepared jars of it. Botulism is a real threat with garlic and unless you have commercial canning equipment, it's is strongly suggested that this not be done. Garlic grows under ground and even with peeling and washing well, you may not be able to remove all of the things that can cause botulism. In vinegar, it will work because the acid will inhibit the growth of botulism, but in either oil or water you need the high pressure canning equipment and I still wouldn't trust it if it were my mother. The jars available in the grocery are not that expensive.