patrick260z

Just to expand on what PeteB said concerning the regs for using bad wine. You must call it substandard brandy, but that is only for wine with major microbial spoilage. So high VA wines, basically. Highly oxidized wines... aka Sherry do not fall into that category. There may be limits to the g/100mL of VA set for distilling wine that are different for those set for bottled wines.

Copper carbonate? It's green. You said you use soda ash, right? Maybe residual soda ash, not complete neutralized by the citric or rinsed out by the hot water reacting with the copper condenser. Have also heard of excessively gassy (CO2) charges can also cause lime green distillates.

Good insight with the rum production. Seems a single run "all in" for that one hour of reflux might give enough difference to compare with a standard run, if there is any.

How much reaction can take place in the few hours of heat applied during distillation? In my observation and understanding most esterfication takes place in the barrel. My understanding is that these reaction take a long duration of heat, and your organic acids are coming from whats in the wood. If you can't find the answer, run multiple trials with the variable being heat. Would be interesting.

Blue, you're absolutely correct about everything you've said. However, the intent to use the copper sulfate was not to buffer against sulfuric acid reducing to sulfite. It's to react with H2S. I don't believe the problem being discussed is a SO2 problem and I don't think its plausible that a wine (unless completely bleached with sulfur) would ever be saturated with sulfate. It sounds like a reductive wine problem. One can lab bench trial for reduced wines based on the Scott Labs methods found on their website, I believe. Find out which treatment (just Cu or Ascorbic + Cu) changes the smell of the wine material the most. That being said, ascorbic acid can really tear up a wine, too. Just as blue said earlier, your best wines are going to be the wines you don't have to treat for sulfur.

If it is stinky sulfur then you have hydrogen sulphite or a more stable mercaptan. Hydrogen sulphite is readily reactive with elemental copper. So a clean copper surface in your vapor path should clean it up. Additionally, a copper pot would also help. In lieu of those, copper sulfate (the blue granulated type) can be added to the pot upon charging and should strip out the stink. Make sure to hydrate the copper sulfate w/ distilled/RO water. If it is a more stable mercaptan, you'll need to brake the mercaptan apart with an ascorbic acid treatment, then treat the released hydrogen sulphite with the copper. The "sulfite" I think a lot of people are talking on this thread about, is the Free unbound SO2. Smells more like a match stick and is a very harsh respiratory irritant. Very different then the reduced sulfur smell talked about above. If it is that, hydrogen peroxide will take it out to produce sulfuric acid. Sulfuric acid will stay in solution and not distill off. This is a reaction that, if there are large amounts of so2 in the wine, takes some time to reach equilibrium. You also need to make sure when you add it to heavily so2 wines, you'll need to agitate the wine and slowly add the H2O2. If it is just a slight (less then 10ppm TSO2) amount, then toss it directly to the pot upon charging. Classick's mention of the web site add calculator is a solid tool. I've used it myself.

reduction stink? Like rotten egg?

Thank you, very good information. I had heard of there being issues with congener precipitation below 90 proof, but what you're saying makes good sense. Thank you for all the information!

jamie, thank you for the reply. That's really interesting. So now the next question... how slow? Thanks!

Great info, glisade. Pointed me in the right direction, anyway. So, is the slow watering back method to keep congeners suspended or avoiding de-esterification? Is it primarily to preserve a clear liquid or preserve bouquet/aroma? Both? Anyone? T

Hey y'all, Doing some research concerning grappa production and I've found something that keeps popping up. Seems some producers water their grappas back to bottling proof in small doses over long periods of time, sometimes months. Is anyone out there doing this? Any resources out there explaining why this is done, and how it works? Thanks

I understand the production of methanol using enzymatic activity on pectin, but I'm more interested in what's being broken down into fermentable sugars when it comes to enzyme use on grappa pomace/grape skins, as mentioned by mcsology. Or is that not what was being suggested?

mcsology~ Interesting info about the enzymes. Can you elaborate?

Meerkat; I believe, per the illustration provided by StonesRyan their still has the dip pipe design.

Your effectively making blueberry wine for distilling, right? And its in a carboy? How does it smell? Do you have a press?