Here is a graphic illustration of a typical reflux run collected into 20 containers. The top row shows blended colours in each container, and the bottom row shows the the same run with colours separated into layers in each container. The last (21st) container is what's left inside the boiler with <1.0% ethanol.
Main points are:
- Foreshots contain a small quantity of meths and acetones but take a lot of heads along with them to be sure.
- There's a lot of ethanol in the heads and tails.
- The hearts contain very little heads and tails.
- Re-running the heads and tails should produce a similar picture; only the hearts cut may be a bottle or two less.
The problem is they are all colourless and you have to 'see' by taste and smell
Edit..here is another pic for the pot stillers There will be some over-run of heads and tails into the hearts. There are skills in getting good heads and tails into the hearts. This is beyond my scope.
When stripping a wash you may find the following in order... Main points are
- the water content will rise constantly while the ABV drops constantly.
- the heads and tails will overlap but this is of no concern.
- the aim is to get the average ABV up to at least 40% and then do a proper run.
(Click the pic for a sharper image, then click the back button to get back to here...if you click the 'X' you will start all over again).