You can do a simple test for methanol by placing some in a non-flammable container and burning it (putting some on a spoon will work fine):
- Turn off the lights and watch the color of the flames.
- If there are red or yellow flames, these are impurities and you should not drink it. (With experience you can redistill this alcohol to remove the impurities.)
- Taste it, if it tastes like rubbing alcohol or acetone spit it out and don’t drink it.