Apparently, a minute amount is produced in the fermentation...
Something new every day.
https://www.abc.net.au/health/features/stories/2013/09/10/3845522.htm
“Methanol is formed in very small amounts during fermentation, the process by which alcohol is made from plant products like grape juice or cereal grains. There are small amounts in wine and beer, but not enough to cause problems when these products are made at home, says Leigh Schmidtke, a senior lecturer in wine microbiology and production at Charles Sturt University. But home distillation to make spirits like gin or rum concentrates the levels of both ethanol and methanol.”
Methanol is produced by the beakdown of the pectin. Different grains/grapes have different amounts of pectin.
Which is why freeze distilled products like early applejack were dangerous
Colonial would set bucket of hard cider outside in winter
Water would freeze concentrating alcohol and other esters including methanol in resulting liquid
Do it few times and could get really toxic