Other methods exist for opening jars without jar openers, but many of them are not as easy to use as jar openers. A hot water tap can be used to open glass or plastic jars, for example. It is possible that this method can harm your health since heating plastic can release BPA. Submerging glass in hot water can break it. In fact, the jar opener is the fastest and easiest method. You can enjoy these advantages by using the jar opener.