Distillation of alcohol beverage not working.

[u/Any-Concept3271]

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)

[u/ChemSciGuy]

Use more wine. Starting with only 15 mL means you will get 1.5 mL if you had an ABV of 10%. Your glassware has too much surface area for such a small volume of distillate.

[u/Ok_Path8613 → u/ChemSciGuy]

This. 15 ml wine is roughly 1,5 ml ethanol. Depending on the setup not enough to even fill the columb completely with vapor.

[u/SauceyMerchant → u/Ok_Path8613]

Agreed with the above comments. One thing to add is to consider making the column shorter. One lesson learned from hobby distilling is you want just a little more head space (20-30%) than what is necessary to keep from boiling over. Extra unnecessary space will ultimately mess with your yield towards the end.

Make fine, slow temp increases as you approach the BP of water. I only increase the temp by a degree once I stop seeing distillate. It's a long and slow process, but if the goal is to have something potable at a significant yield that's what it takes.

[u/_Estimated_Prophet_ → u/ChemSciGuy]

This is the answer

[u/Ore-igger]

Listen here son, you need atleast 5 gallons of corn beer at a minimum 12% AVB. Then you need yourself a copper stil atleast 500 watts, a -500 watt condenser. Then ooh baby you got some moonshine.

[u/yycTechGuy → u/Ore-igger]

Oddly specific ! LOL.

[u/kugelschreibaer]

Insulate 11&2

[u/Any-Concept3271 → u/kugelschreibaer]

Would definitely try this. Thank you!

[u/Cyrlllc]

Might be a stupid comment but have you checked if your sample is boiling?

[u/Any-Concept3271 → u/Cyrlllc]

Yes it was. We already collected and discarded the forerun. However, #2 drastically changed temperature even though the wine is boiling and the column (#11) stays hot.

[u/Cyrlllc → u/Any-Concept3271]

What is your thermometer reading at the top? Are you seeing a lot of condensate flowing back down the walls of 11?

[u/Any-Concept3271 → u/Cyrlllc]

The thermometer reading actually reached about 70 °C at the top, and we got a few drops of forerun. But right after that, the temperature dropped to below 50 °C and stayed there. I also noticed that the column (11) was hot, but we didn’t really see a lot of condensate flowing back down the walls — it just seemed like the vapor wasn’t pushing through to the adaptor anymore.

[u/Cyrlllc → u/Any-Concept3271]

Try running it with just water and see if youre getting any condensate.

A temperature drop usually means that youre starting to distill over the heavy component. 

[u/karlnite]

I bet all that alcohol in 15ml of wine could adhere to the glass itself and never make it through that rig.