You never know with store bought jals. Sometimes they are bred for low heat and other times they are picked way too early for shipping and distribution. When I do get a real hot one it reminds me of what a jal should taste/burn like. One of the reaons I started growing pepper many years ago was so I could get good, hot, ripe jalapenos, although these days I seem to prefer growing fresnos which always seem to outperform my jals