Don't buy a condenser for distillation. Build one using standard fittings 

My background is 20yrs+ in electrical soldering from BGA to SMD and all manner in between including automotive and AC. I have during that time I have also been a small manufacturer for the scrap metal industry and, seeing you work, I can give you one pretty good bit of advice I've learnt. After a light dry and preheat, start heating only from the bottom and feed solder in from only the top. Copper is an excellent conductor and doing it this way ensures everything it heated through enough for the solder to wick into the joint. It's also an absolute indicator because if the solder won't take from the top then you know the material is still too cold to make a solid joint. I hope this helps.

Another tip: use female fittings on pieces that take the most effort to build. If you drop that liebig and mash the soft copper threads you need to replace the fitting. When you remove the bad piece you can heat the other joints and cause leaks. Best to make it so that is less likely to happen in the first place. And definitely use the ready made tee fitting that already has the reducer as previously suggested. Cheaper and easier!

Nice job Robot, heat is either your enemy or your friend. If you're clean and fluxed like you were with just enough heat to cause capillary action and then stop solder joints will turn out like yours did.

good build!!

They make the T with the correct size outlets. 3/4-1/2-1/2 Reduces your parts count and $$$

quedo hermoso y fuerte felicitaciones

It would be better to have the water inlet and outlet on opposite sides with the inlet pointing down and the outlet up with the whole thing tilted down at the inlet end to ensure no air in the tube and a constant flow of fresh water all round the inner tube. It might work the way you did it but will probably need a strong current of water.

Hint, hint increase surface area on the inner 1/2" Pipe by sanding the entire length for increased condensing.

The way I was shown was to wrap a piece of solid 12 awg bare wire around 1/2 pipe and sweat it onto outside. I did 2 alternating wraps

cool!!!!

We don't have sodder here in Australia, would solder work?

Got to keep your heat on the work when you apply the solder. Taking the torch away as you’re feeding in solder just helps cool the parts.