In 3 days the fermintation will be complete on a batch of rye, but I have been called away on a job and won't have time to distill the wash until 5 days later
I don't think I can leave it in the fermenter as it will get infected with bacteria or wild yeasts.
What would happen if I distilled it before fermentation has completly stopped?
Fermentation should have finished the night before I leave. Could I pump to pot still and heat enough to sterilise, then let it cool and leave in copper still for 5 days? Would there be any bad reaction between copper and wash in 5 days?
Any suggestions please.
Why don't you run it and find out? Next time you can let it ferment until it's done, whatever that might mean to you, and run that. Then you can see the difference for yourself.
A couple of things... Are your fermenters equipped with cooling jackets? If they are you should be able to chill the wash (once fermentation is complete) enough to keep it fresh for several days. I don't know what kind of system you are running or what your batch size is so this may or may not be an option.
Another option would be to keep the wash agitating while you are gone. You are probably running a thick mash (grain in) so keeping the agitator on will keep the solids from settling to the bottom and the beer from rising to the top. There should be enough alcohol in the wash after fermentation to keep it from spoiling to any great degree. We have had to leave mash in the fermenter for the number of days you are mentioning and seen no ill efects as long as the agitators were on.
Running it through the still is the option that the other distiller suggested and is always the safest bet. Consider how far along the fermentation is when doing this. If you've been fermenting for 4 days the majority of your fermentation has already taken place. Distilling on day 4 will probably result in a very minimal loss of volume.
Hope this helps...
A few questions, if you don't mind?
How many days does it take for your rye to reach terminal? What's the last day in that cycle that you'll be able to distill it before you leave? What's the 1st day in that cycle that you'll return? What's the shape, size of your fermenters? Are they open?
If you use properly designed fermenters... ie... with temperature control and glycol jackets, you could do what brewers do and crash cool it to 32 deg. F. This will hold the wash a long time to allow you to distill it later.
I had this case some time ago.
The fermentation was estimated in about 8% ABV, I had my staff adding a small quantity of diluted sugar every two days, that way we always had a small CO2 layer on the fermentation and was fine when I came back to distill it.
We couldn’t detect a big difference (if any) in flavor in comparison to earlier batches.
This is a rough method but worked in the emergency for some days.
Thanks for the suggestions. Distilling early seems to be the easiest option.
This is my first batch through my new distillery, 500 litres of wash in a 1100 L fermenter. I use a lauter tun so there are no grains in the wash. I don't have a cooling jacket on my fermenter and it is closed but not completly sealed.
My previous experience has been in "scotch" style distilleries where they were run on a 7 day cycle. I have not done rye before. The fermentation took off really quickly and this morning (I am in Australia) 2.5 days later the gassing is now very slow and the temperature is dropping. Maybe it will finish in time, another 2.5 days:)
This situation will probably happen again as I am an agricultural contractor and a farmer, so for the future, I will buy another tank so I can hold the wash in my coolstore.- thanks for the cooling suggestion.
I am not so sure about KB's suggestion of leaving agitator running. Having studied micro biology, in theory only, this is likley to increase the breeding of an infection, but in practice maybe not.
Thanks all again for your help.
PeteB, just a quick question andprobably off target: Are you using a whiskey yeast of a super start? 2.5 days seems fast for an semi open fermenter?
Sorry about the slow response! I have been working away, without internet.
I used an american Whiskey yeast. Fermentation appeared to have stopped after 5 days BRIX had stabilised so I ran it through my pot still (wash run) Very poor yield. Just starting another ferment now. Hope this yields better.