Diskussion: Die Schnaps – Destillation

Wenn der Geschmack von Methanol aufällig wäre, dann würde es nicht funktionieren, damit Wein oder Schnaps zu panschen, wie es ja leider immer wieder passiert.
Aber auch heute denken noch die meisten professionellen Brenner, daß sich Methanol im Vorlauf konzentriert. Und daß Methanol der Grund ist, daß Vorlauf schlecht riecht und schmeckt. Viele prof. Brenner haben ja auch keinerlei Ausbildung genossen oder Prüfung abgelegt.
Jedenfalls gibt es deutlich mehr Studien, die belegen, daß Methanol sich eher am Ende des Brandes konzentriert, als welche, die das Gegenteil rausgefunden haben.
ZB hier:
https://publications.europa.eu/de/publication-detail/-/publication/0b908be6-2673-45a5-8c2f-b3b6abc1aa37

"The investigation shows that there is in g/hl p.a. an increase of methanol contents during the distillation and especially in the last fractions (tailings). This is caused by the fact that methanol is, in spite of the lower boiling point (64,8°C) compared to ethanol (78,3 °C), carried over in the distillate later than ethanol, an observation that is also confirmed by former investigations and in the literature. This explains the effect that the separation of tailings, which is done for sensorial reasons (2.3), also leads to a reduction of methanol contents of the middlecuts in g/hl p.a. and compared to mash of between 20 and 30 %.

"An extremely late separation of tailing can perhaps cause an increase of methanol contents of about 20 % in the middlecut."

"methanol contents keep a higher value for a longer time than ethanol contents."

oder hier:
https://www.bostonapothecary.com/wp-content/uploads/2013/01/peardistillatesfrompearjuiceconcentrate.pdf

"it can be seen that methanol concentration increased from values around 10-15 mg/L in the first fraction to values around 40-55 mg/L in the middle of the distillation, and then remained constant or slowly decreased until the end of the process. Le´aute´ suggests that because of its low boiling point (65.5 °C), and high solubility in water and ethanol, methanol distills in the head and heart of the distillate only (16). However, studies made by Herna´ndez-Go´mez et al. on melon fruit distillates found methanol in all of the distillation fractions (17). They indicated that this behavior is only to be expected due to the formation of azeotropic mixtures. Apostolopoulou et al. also found methanol in all of the fractions (heads, hearts, and tails) of traditional Greek distillates (18). Finally, Glatthar et al. found the same behavior for pear distillates (11). So, our results are in agreement with these last publications."
"Methanol, specified in ml/100 ml p.a., increases during the donation, while the ratio ethanol : methanol is lowering down. This effect seems to be rather surprising regarding the different boiling points of the two substances: methanol boils at 64,7°C, while ethanol needs 78,3°C. So methanol would be regarded to be carried over earlier than ethanol."

"The main factor that leads to an increase of methanol in the distillates is the recycling of the tailings. Tailings are either add to the next mash to be distilled or collected separately and re-distilled in a separate distillation. Both procedures lead to an increase of methanol contents of between 10 and 20 % gathering all achieved distillates."

"The main reason for high methanol contents (above 1200 mg/100 ml p.a.) is the recycling of tailings, which is practiced in many distilleries, especially in small ones."

"The analysis of the behaviour of methanol during the distillation shows that it is carried over later than ethanol in spite of the lower boiling point. So when the contents of the different fractions are referred to pure alcohol, methanol appears in the highest concentrations in the tailings."