白兰地的蒸馏理论

白兰地中的挥发性化合物有的来源于葡萄原料，有的在发酵过程中形成，通过蒸馏进入粗馏白兰地，形成白兰地特有的香味，在蒸馏过程中，低沸点成分不发生化学变化，含量基本保持不变，高沸点成分要发生化学变化，有些物质的含量有所增加或减少，有些物质将重新形成，显著增长的是醛（74％）和酯类（17．4％），此外，蒸馏过程中还发生物质的分解，由于高温，中间氧化剂和溶解氧的存在，使酒精氧化成乙醛和乙酸，酯化作用的同时发生酯的分解，用铜，铁蒸馏釜蒸馏，挥发性成分形成多，用玻璃烧瓶蒸馏，挥发性成分形成少。

Distillation Theories of Brandy

The volatile compounds in Brandy come from grape material or form in the fermentation, and the specific flavour components come into the crude distillate by distillation. During distillation, the contents of low boiling components remained the original levels and no chemical reactions occured; the contents of high boiling components increased (aldehydes and esters with increase of 74% and 17.4% respectively) or decreased and some components reformed and chemical reactions occured. Besides, decompound also occured during distillation. The presence of high temperature, middle oxidizer and dissolved oxygen oxidized alcohol into aldehyde and acetic acid; decompound of ester was concomitant with esterification. Distillation by copper or iron kettles resulted in more volatile components compared with distillation by glass flasks.(