Introduction
The iStill 50/250 family has programs for automated Fores and Heads collection. What do these programs do and what is the difference between them?
Fores and Heads, in general, refer to the first parts of the run, when very light alcohols come over. Very light alcohols like acetones, methanol, and ethyl acetate. "Fores" are the very first parts, where most of these alcohols are gathered. "Heads" refers to the phase after that, where lighter molecules from the alcohol family still blend over into Hearts.
Since the Fores and Heads associated alcohols cause hangovers (head-aches, to be more precise) and since you don't want your customers getting head-aches, after drinking your product, it is important to get rid of them. That's where our programs for Fores and Heads removal come in handy. At the same time ... some products, especially fruit brandy's, get most of their taste from some smearing of late Heads into Hearts. Our automation is therefore not only about removing them, but about removing them in a controled manner.
Fores removal
The iStills remove Fores right after the column is heated up. The Fores removal program helps you to achieve two goals:
- Clean out the column;
- Get rid of the most concentrated lower boiling point alcohols.
After the previous run, the iStill keeps some alcohol in the system. It helps sanitize the needle-valve as well as solenoid sections. During Fores collection this "old" alcohol is flushed out of the system.
During Fores removal, also the first parts of the alcohol of the current run is discarded. Since heating up the column in itsself causes some 100 re-distillations, these first alcohols are heavily contaminated with lower boiling point molecules. Alcohol that has just been used to give the column and its packing an extra cleaning and alcohol that's concentrated with head-ache causing molecules? Yeah, that's why we have a seperate Fores removal program. It is also why we want you to always toss this faction.
The standard factory setting for Fores removal of 78.5 C does a great job. But off course the total amounts of lower boiling point alcohols very much depend on the fermentation process that takes place prior to distillation. By upping or lowering the standard setting of 78.5 C to for instance 79 or 77.5 C, you can influence the size of the Fores cut. A higher temperature setting will lead to a bigger Fores cut. A lower temperature will cause your Fores cut to be smaller.
Heads removal
Once you got rid of Fores, thinking about how you want to deal with Heads is next. Heads is the phase during the distillation process where less and less lower boiling point alcohols contaminate Hearts. Early Heads are pretty bad. Late Heads have a lot of fruity notes to them that are very important when creating great fruit brandy.
In other words: we want you to be able to manage the Heads cut!
The Heads removal program usually starts after a prolongued stabilization period of 30 minutes. During stabilization we give all the molecules in the boiler a chance to enter the column to be sorted out: lower boiling point, lighter molecules gather at the top. Longer stabilization leads therefore to a more concentrated Heads cut. And a bigger, cleaner Hearts cut after that.
After stabilization, the iStill starts to collect Heads in a few drips per second. By manipulating the setting of the needle-valve opening (just push "+" or "-"), you can increase the collection rate. A higher needle-valve opening will lead to a bigger Heads cut.
How you can play around with that? Well, for a normal vodka, whiskey or rum, in the iStill 250, you may aim for 600 mls of collected Heads. Try 300 to 400 mls for a fruit brandy. And around 200 mls will serve a gin very well. Base line? You make the decisions, while iStill supports you by making Heads collection easy. And if you are happy with a setting, you can push "OK" and save that setting for future runs.
Regards, Odin.
