For context, I’m a chemical engineering student currently taking organic chemistry, and my group recently performed a distillation of an alcoholic beverage (wine, ~15 mL sample). We used a small distilling flask, a vertical column, a thermometer at the head, and a condenser connected through an adaptor (the connector between the column and condenser, which I’ll call #2). Cooling water was run at a moderate rate (bottom-in, top-out), we added boiling chips, and greased all joints to prevent vapor leaks. At the start, we observed a short forerun of 2–3 drops, during which adaptor #2 became hot and the thermometer climbed to about ~70 °C. But after that, the adaptor suddenly cooled down drastically, the thermometer reading dropped, and no further ethanol distillate came over, even though the column itself stayed hot. This confused us because we expected that if the column was hot, vapors should have continued into the adaptor and condenser (with ethanol boiling around 78 °C). Could this cooling be due to premature condensation inside the column before the vapor reached the head, or does this suggest an issue with the adaptor itself? I’d appreciate any insights on why this happened and what adjustments (heat input, condenser water rate, etc.) we should try to maintain a steady ethanol distillation. (Attached is our set up)