Distillate strength reduction.

Brewmeister · Post by **Brewmeister** » Tue Sep 26, 2006 11:31 pm

I finally done my run the other day - put 40 litres of 16% Sugar wash through my valved reflux still - took forever and a day from start to finish and I ended up with just under 5 litres of 'good' hearts at 94% ABV. (checked the following day with correct temp of spirit etc for the alcoholmeter)

After taking the advice of 'The Knowledgeable ones' on the board I decided to carbon polish the spirit to make sure I had no nasty flavours. Even though tasting it after it had sat for a day, it tasted quite good and ' bloody strong' with a BIG burn but there was something in there that I quite can't put my finger on as to its taste - a bit sweet but not overly though.

Somewhere in my readings of all the posts on carbon polishing etc I found that a few guys had experienced a drop in %abv strength after running it through the carbon and some had mentioned that they cut to a higher %abv before polishing to compensate for the loss.

With this in mind I decided cut to 55% 'just in case' - checked with alcholmeter before I put it in the filter and it was at 55% - now I have just checked the %abv on 250ml of the output I have so far and sure enough it is down to 40%.

Can anyone explain the reasoning for this and is there a way to stop losing the strength (other than the obvious and make a clean spirit that doesn't need polishing)

Thanks in advance.

junkyard dawg · Post by **junkyard dawg** » Wed Sep 27, 2006 12:31 pm

I haven't read any posts that lead me to believe that carbon polishing will lower the ABV. If I had to guess what that might refer to, it would be that the water used to hydrate the carbon dilutes the spirits. Not hard to correct for... Just add spirit at the correct proof to account for the water in the carbon. I bet that the weight of the hydrated carbon would be the best way to judge the water content.

junkyard dawg · Post by **junkyard dawg** » Wed Sep 27, 2006 12:33 pm

oh, and I also thought, doing a stripping run first, before the 94% spirit run will save you some time overall.

Brewmeister · Post by **Brewmeister** » Wed Sep 27, 2006 1:58 pm

junkyard dawg :- I haven't read any posts that lead me to believe that carbon polishing will lower the ABV. If I had to guess what that might refer to, it would be that the water used to hydrate the carbon dilutes the spirits. Not hard to correct for... Just add spirit at the correct proof to account for the water in the carbon. I bet that the weight of the hydrated carbon would be the best way to judge the water content.

I definitley have read it somewhere - as I have mentioned before in one of my posts - I have done that much reading of late am getting 'square eyes' and maybe a bit of information overload - but I definitley did read it as someone did mention only cutting to 55%ABV because of that very same reason of getting a further diluted outcome - which is what I have.
I didn't Hydrate the carbon before polishing - the carbon I use is pre-washed and also the instructions that came with my Fuselex filter stated to fill the column with carbon, then pour the spirit on - let is sit for min 45 mins and then take off at 2 drops/sec which I have done except I let it sit for about 1.5 hrs.
So there has been no dilution by any 'extra' water etc.

oh, and I also thought, doing a stripping run first, before the 94% spirit run will save you some time overall.

I didn't do a stripping run this time as being my first run I wanted to go through all the motions 1st to see how everything works etc and boy did I find out the 'hard way' - I think I will be doing stripping runs from now on.

Enlikil · Post by **Enlikil** » Wed Sep 27, 2006 2:55 pm

When you filtered did you use a Filter appurates or did you toss it on carbon in a container?
I noticed when I used the Z-filter my first 750 ml bottle was considerably lower in ABV. I think it is becuase i started collecting right away and there was more water in that filter then i anticipated.
My Stuff that comes out of my carboy doesn't seem to have the same problem.

Brewmeister · Post by **Brewmeister** » Wed Sep 27, 2006 3:18 pm

Enlikil :-When you filtered did you use a Filter appurates or did you toss it on carbon in a container?
I noticed when I used the Z-filter my first 750 ml bottle was considerably lower in ABV. I think it is becuase i started collecting right away and there was more water in that filter then i anticipated.
My Stuff that comes out of my carboy doesn't seem to have the same problem.

No I used a filter apperatus - it is this one here
http://www.homebrewkegs.com/filter.php" onclick="window.open(this.href);return false;" rel="nofollow
works well and is very easy to use plus as I mentioned before I didn't put water in with the carbon to start with and also I waited at least 1.5 hrs before I started to take off at 2 drips /second.

junkyard dawg · Post by **junkyard dawg** » Wed Sep 27, 2006 4:25 pm

thats a nice filter rig... Let us know how your distillate comes out. No more problems with precipitates?

Brewmeister · Post by **Brewmeister** » Wed Sep 27, 2006 4:33 pm

junkyard dawg :- thats a nice filter rig... Let us know how your distillate comes out. No more problems with precipitates?

Thanks for that - they're not cheap but are really easy to use and work very well - the one I have actually has a small tap on the bototm of it so as to be able to adjust the flow rate - you can see it pictured on this site
http://www.qualityhomebrew.com/store/co ... roduct=909" onclick="window.open(this.href);return false;" rel="nofollow
the cook decided she would buy it for me for Father's Day and I couldn't get the money off her to pay for it quick enough.

The distillate is coming out clear as crystal - no precipitates etc at all - I think the problem I had with that other stuff was because it was a 'cheap cardboard wine'.

I have over 2 Litres filtered now and just checked the %ABV reading and it is now just below 55% ABV again - this is weird - the only thing I could put it down to is as you have suggested JD maybe some water within the carbon - it comes already prewashed very little dust etc so maybe this could be the cause as the readings are now back to what they should be.

Thanks again for all your help.