JustAndy

If you are spending several weeks proofing you don't necessarily need to take a reading if you are tracking the total water addition. But also it takes like 5 seconds to take a reading if you have a handheld density meter and perhaps 90 seconds if you have to use a hydrometer. I understand that everyones business functions differently and there are many price tiers and product niches, and slow dilution might not fit every business model. But to not use it because you are worried your employee cant do basic math? Or punch some numbers into a program? 

I distilled cider for a couple of cider marker's pommeau. The traditional way in Normandy would be either double pot still distillation or low-rectification continuous column depending on the region, and would work out to about 60-70% abv brandy. I distill ours at about 78% on a 3 plate pot still, our orchardist prefers that as it allows more apple must to be in the blend to hit the right mix of sugar and acid. The apple must seems to matter more than the brandy, if there isn't enough tannin or acid in the apples the pommeau will be very flat and blah. 

50 ppm is a lot to me, your still will survive but will likely need a good cleaning and acid refresh afterwards, and there will be quite noticable SO2 in the spirit. Apple cider can have other problems like acrolein, so I would certainly get a sample to distill before committing to doing it. 

If they have a winery license they can make pommeau, but on paper it must be a blend of fermented cider and brandy, not unfermented apple must and brandy (which is technically a liqueur and would require a DSP). So the producers I know initiate fermentation and then arrest it a few hours later with brandy .  

Arak is not terribly relevant to a discussion about bacterial strains, but there is fair archaeological evidence that puts origin of alcohol distillation into 3rd century India, and some place it in China. Safest to say that scholars disagree. We make an 'arak' for a restaurant group using grape brandy and Syrian aniseed, its fun, they mostly use it in cocktails and tiki-style drinks. 

Without knowing more about what you are currently doing, my advice would be to treat it like anise and distill a concentrated macerate of fennel and spirit all the way out until it is milky white/1%abv/just about dry and then put that phlegm in the next distillation or redistill it and use it as an essence. 

I second that its the SNAP 50 and not residual sugar (which will not be present in spirit after distillation) in rum or cask extractives (unless it's spending 18 months in a 10 L maple syrup barrel or similar). 

This sounds snarky and I apologize for that, but the best way to answer these questions is to hire someone who knows how to operate a still. 

Since you've got them in the tote, give them lots of oxygen and slowly proof them down over the course of a couple months and you might be able to better integrate some of the wood. I would probably put them back into used fullsize bourbon barrels at a relatively low proof for a year or two and see what happens.  

Are you planning to 1. store the barrels and 2. do the blending & bottling at your own facility?

If you have cash and a place to store the barrels I suspect there will be plenty of inventory available in the next 6 months as operations close or need quick cash survive the downturn. 

Many cooperages in California, the barrels will be more expensive but shipping will be much cheaper if you are ordering less than full truck loads. Seguin Moreau makes nice barrels in Napa, and so does Demptos. They are generally much higher quality barrels than ISC or the other kentucky cooperages from my experience. We used to use Kelvin and then ISC but I think we will be moving to Seguin as shipping is getting outrageous for MO->OR for the small quantity of barrels we need. 

I've worked at 4 distilleries; I've worked for 8 years at a 100% grain-to-glass distillery where we make about 30 different spirits (fruit brandy, whiskey, wine brandy, liqueurs, misc), a few years at a larger distillery which did malt whiskey and about 30,000 cases/year of gns based gin, a midsized distillery that focused on vodka/gin/simple liqueurs, and a start-up that did gns-based spirits which I left over their misleading labels. So i am not insensitive to Roger's points about some of the dishonest marketing practices which are deployed, but I have first hand experience that redistilling GNS can sometimes be beneficial and worth doing. I've also done consulting for a handful of projects but more for fun than for profit. My wife also writes for numerous wine & spirits mags (and just wrote a book about scotch), and I travel a lot with her visiting other producers which is always very educational. 

I worked a place that redistilled GNS through a 20 plate column, and there was a clear heads component that was removed. The distillate was noticeably cleaner than the starting GNS, and also different than the same GNS run through carbon. The distillery used 3 different GNS sources for various contract projects, and there were differences between them and they performed differently under redistillation (meaning a different sized heads cut). We also made a vodka on the same column from a 100% wheat mash base. It's not very interesting to redistill GNS and I'm glad I dont need to it anymore, but there are certainly reasons to do it beyond the label impact.     

Pitching yeast into a mash that already has alcohol in it is stressful and damaging to them. At the beginning the yeast are building their membrane walls and reproducing and the presence of alcohol can affect this behavior. There are some components of heads/tails that can be consumed & cleaned up by yeast during fermentation, but I would add to an already working fermentation if that was the goal.  

It sounds like you aren't using a commercial still, please make sure you have an appropriate pressure release valves and safe discharge piping, especially if you are running mash in the thumper. 

If your mfg doesn't know all this stuff already, you are probably in for a nightmare to get a 3 column system to perform adequately. 

I totally agree with what you're saying about the local rate of water addition, but I think there is also a chemical transformation (or maybe it's physical, I am an accountant by education...) related to adding the water in small (slow) doses over a longer period of time. Each addition of water is accompanied by an infusion of oxygen from the mixing process and then this is given time to settle and normalize with the environment before the next addition. It seems to better protect the nose/perfume of the spirit. A cognac distiller told me the dilution must happen slowly enough that almost no raise in temperature occurs (for the mixture of alcohol and water). 

I certainly can't explain exactly what's going on, but my experience doing it both ways directs me going slowly, which aligns with the guidance given by enough distillers who I respect to think that it is a real phenomenon. I look at it as the difference between chopping garlic and smashing it. Scientists have proven why there is a difference in flavor (in the 90s there was a big boom in garlic research), but my great grandmother who couldn't read also knew that it happened without caring why.

They do have a certification, but it has very little meaning. I know of an ADI 'Certified Farm Distillery' that has never produced anything from raw material, their products are a GNS based vodka (no redistillation), a GNS based gin, and a pre-aged kentucky bourbon which they illegitimately label as distilled in Oregon. So these certifications are all kind of meaningless without enforcement. The only certification I can think of that has any enforcement at all is the certified texas whiskey program https://texaswhiskey.org/ 

I've worked at two places that dilute from still strength to bottling strength in a day or two, and a place that takes 4-6 weeks. My organoleptic experience is that there is a significant quality impact to diluting brown spirits like whiskey and brandy rapidly. Taking time to do it might be a luxury, but we produce a luxury product and an extra month is negligible if it's already waited 4-6 years in barrel.   

Tank stratification was an issue at one place where the gin was proofed rapidly in a 2000 gal tank, but thorough mixing is required whether you are diluting a small amount or a large amount, fast or slow.   

19 minutes ago, Musicman9492 said:

I'm all for questioning the "slurry". I've been questioning it since day one, however the fact that it was able to ferment 650 gal of 1.085 right down to 1.006 tells me that there is only, at max, 6 points of truly unfermentable sugars/materials in the recipe

That's only true if the yeast slurry and the rum backset were the same, since the additions happened 10 days apart I would question that they were from the same batch. If the slurry was just sitting for 10 days, it's likely to be less healthy / have lower vitality and cell count. The backset could also be from the top of the tank (clearer) vs bottom of tank and sludgier with more unfermentables, ash, etc that skew your readings. 1.085 to 1.015 is 80+% attenuation which is what Omega lists the yeasts specs as,  and it might have died out earlier in the 2nd batch from the combination of less viable slurry and damage from starting fermentation in 5% abv medium with a crashed pH. 
 
I wouldn't be concerned about the flavor contribution of champagne yeast at this point, I would be more worried about spoilage from the incomplete ferment sitting. If you add champagne yeast I would check out scott labs helpful guide, as it's a pretty harsh environment to pitch yeast into https://scottlab.com/restart-stuck-fermentations

hindsight is 20/20 but it would have probably worked a lot better to combine your 4 ferments into 2, and then started 2 new ferments. 

On our still the thermal mass of the water in the depleg at the start of the run is enough to condense all the vapor, load the plates, and cause the still to run in total reflux for about 5-10 minutes. If I wanted to stay in reflux, I would need to use the manual bypass valve but that's not usually what I want. There are instances where having separate inputs for the depleg and product condenser would be nice, but having used stills setup that way they are much fussier to get adjusted and keep consistent.   

200 gal of yeast slurry seems insane to me, where is it coming from? Did you measure the pH throughout the process ?

4 hours ago, Southernhighlander said:

We found that the best placement for the Danfoss probe is at the coolant output of the final condenser and the best place for the valve was at the coolant input of the final condenser.  Also we found that you need to have just a little bypass at the valve to make things work smoothly. 

This is exactly how our 3 plate Kothe still is setup. The manual bypass valve is important, as you need to be able to flow water to make sure the water retained in the dephleg is starting out cold and not hot from a previous run. 

Is the lab still glass and the other copper? Grapefruit aroma is sulfur based, which copper can reduce.

I can tell you we use sodium carbonate, which definitely works, why what you're doing isn't working is beyond my scope. 

I dont see anything in your links that suggest using calcium hydroxide instead of sodium carbonate. I would look at the solubility, a quick google suggests that calcium hydroxide is "is only slightly soluble in water (0.16g Ca(OH)₂/100g water at 20°C) forming a basic solution called lime water. The solubility decreases with increasing temperature. "The solubility decreases with increasing temperature. "

We use soda ash (Sodium carbonate) which works well enough at a smallish scale and is relatively easy to source and safeish to handle. It depends on the stillage, but it's about 2 - 3 lb to bring 900 L of whiskey stillage up to 5 pH.