You don't really. Although if one were say a good methamphetamine cook and knew what mostly pure meth tasted like. That or the distributor that buys that pure meth and then cuts it. But they could be fooled based on taste.
Point is it actually probably is possible to a degree but you'd need a great deal of experience, and it still it would only get you so far. Human taste receptors are pretty precise machinery. Obviously things like unusual sweetness or saltiness are indicators of something.
But there are plenty of things like taste like meth. For instance phenethylamine crystals taste alot like meth. When smoked they also are reminiscent of meth. So again its hard to do without tasting a large variety of things.