In my early days as a piper I thought it was necessary to dump the ash and restart from scratch on relight. DON'T ! I now do what others described - light tamping and no dumping before proceeding. The only thing I don't think has already been mentioned is this -- if a pipe is acting like it's going to go out, it's best to let it do so. Forget the idea that you're doing Somthing Wrong if you use more than a few matches per bowl. Heroic puffing to keep a pipe lit just heats everything up, encourages moisture and is just plumb unnecessary and counter productive. If your pipe tastes bitter after relight, it's possible that you've lit a hot pipe with wet tobak. So after the pipe goes out, let it cool off. After the cool-off period, tamp lightly and then apply the match. (Actually, it doesn't matter which order you do cool off/tamp.) As mentioned by other posters, the relight is affected by a number of factors which you'll get the hang of with a bit of patience and experimentation. But let your pipe cool off before relighting.
