Bourbon yield question

[Christopher ONeal]

Hello forum dwellers! This is my first post, though I have been lurking for quite some time. I was hoping to get some advice, or at least possibly some insight, into a yield question.

We are distilling bourbon from a corn and wheat mash (64% corn, 26% wheat, 10% malted wheat) on a 6 plate hybrid still (Figgins reciprocating 2000L). We do a single pass with all plates active. Our distiler's beer averages about 10.5%, and our yield per run has been about 82 proof gallons for the last year (final distillate at ~135 proof). Some exceptional runs have made it to 94 or 95 proof gallons, but the vast majority of our runs are in the low 80s. Our heads cut is standardized at 2 gallons (true gallons, no proof measurements are taken on the heads for cutting purposes). Our tails cut has been made to taste, but with certain still parameters in place (steam open full, dephleg open wide with dephleg temp reaching approx 200 F).

Within the past month, however, we have had multiple runs reach 110+ proof gallons (final distillate ~141 proof). No changes in our mashing or fermenting parameters, no changes to our yeast (we did make a yeast change 5 months ago, but this has been only in the last month) or to the source of our grains. Our mash is finishing at the same (or nearly the same) SG as our previous mashes, and our fermentations have always run to .998 or .995 as they continue to do. We have lowered the steam pressure for the majority of our run from approximately 50% full steam power to closer to 30% (our steam is controlled by a single round valve wheel that we have marked for turning correctly, but cannot be super precise with our power). Our condenser is run on a constant 41F water supply from a chiller, but our dephlegmator is piped to city water, which varies widely due to external temps.

The truly confusing thing is that the runs are not consistently this high. We run 4 batches a week (one from each of our fermenters), and we never know until we do the run whether we are going to get an ~80 opg run or a ~110 pg run. There is no correlation to which fermenters the stronger runs come from, nor from time of day or any variable we can pin down. It's happening often enough, usually 1 or 2 a week, that something must have changed. We are a small crew of 3 with just 2 people ever running the still. To eliminate the possibility operator differences, for the last couple weeks we have had the same man running the still, with the same results. We are in New Orleans, and so the ambient temperature has varied widely (from as low as 45F to as high as 82F) over the last month, but we've not been able to correlate that to the yield either.

Any advice or thoughts would be helpful, as we are ecstatic with the extra yield (the flavor is great as well), but are pulling out our hair wondering a)what we've been doing wrong the past year leaving so much in the still, and b)how we can get these results with any kind of consistency.

Edited January 11 by Christopher ONeal
typo and grammar

[FIVE x 5 Consulting]

That's a noodle-scratcher!

The first thing that comes to mind is your gauging methodology.  Are you measuring your outputs volume by weight or by sight glass?  Hydrometer/thermometer method for reading proof, or something else?  If you have multiple operators and temperature swings, the chances of this varying increase.

I had a client recently tell me about a discovery they made. Starting gravities were substantially lower than expected for some cooks.  Looked like some wacky process thing that they needed to investigate.  Turned out it was a new operator that was leaving rinse water in sampling vessels and diluting the wash pre-measurement. All was well, it was just a measurement error. 

[Christopher ONeal]

Thanks for the quick reply! All outputs are measured by weight. For reading proof we use an Anton Parr DMA 35 during the run, with hydrometer/thermometer confirmation on final tote volume.

We've not seen a difference in starting or finishing gravities. We use TILTs for overnight monitoring (we have had cooling issues and temp spikes over the summer when it gets crazy hot here) but manually check SG with hydrometer/thermometer twice daily to confirm.

[FIVE x 5 Consulting]

I got nothin', then. Very curious to hear how this shakes out, hope you'll keep us updated!

[Kindred Spirits]

So this seems to be the change that has resulted in your increase. You said:

"We have lowered the steam pressure for the majority of our run from approximately 50% full steam power to closer to 30%"

Running at a lower steam input reduces the vapor flowrate leaving the pot, which in turn allows the reflux to be more effective in the helmet and column. The result is a longer run, but better separation and better yield. 

[Christopher ONeal]

@Kindred Spirits Thanks for that insight! We had suspected that, as we have long theorized that better separation would be of extra importance for a single pass run, but our team here has more theoretical than actual experience.

Our boiler is older. Would variations in boiler pressure be enough to explain the inconsistency?

 

[Kindred Spirits]

51 minutes ago, Christopher ONeal said:

@Kindred Spirits Thanks for that insight! We had suspected that, as we have long theorized that better separation would be of extra importance for a single pass run, but our team here has more theoretical than actual experience.

Our boiler is older. Would variations in boiler pressure be enough to explain the inconsistency?

 

It wouldn't be the variations in the steam pressure, but rather the flowrate of the steam coming into the jacket of the boiler.

If you guys want some hands on, on-site training, let me know. I would love to come help out and teach you the best way to run your equipment.

[Christopher ONeal]

@Kindred Spirits Thank you for that offer. Those questions are above my pay grade, but I will definitely send it up the ladder!

[JustAndy]

When you are saying 110 PG yield, is that the total alcohol collected (heads + hearts + tails) or the hearts? If the 110 PG is the total alcohol collected, what is the abv at the parrot when you turn off the still and stop collection. 

when you say "steam open full, dephleg open wide with dephleg temp reaching approx 200 F" does that mean water flow to the depleg is as high as it will go? And what is measuring 200F, the water out or a thermometer in the vapor path? 

My guess is you aren't running the dephleg consistently and are turning off the still too early. So when you are running with higher steam/more heat/hotter incoming deplegwater, you are getting less reflux and thus getting to a lower parrot proof earlier in the collection and then leaving more alcohol in the pot when its turned off.  

[DeerHunter]

Am I missing something? 528 gallons at 10.5% alcohol means there are 55.44 gallons of 100% alcohol going into the still. 110 proof gallons coming out would be 99.2% efficiency. I find that unlikely, or am I mathing wrong.

[adamOVD]

In addition with what @JustAndy said, are you dumping your tails into the next batch? Could you be running a batch inefficiently and then passing retrievable alcohol into the next batch, which is then run longer with more reflux towards the end of the run, retrieving the alcohol from the previous run? 

135P seems low through 6 plates if run in the conventional manner.

[Christopher ONeal]

On 1/11/2024 at 3:17 PM, JustAndy said:

When you are saying 110 PG yield, is that the total alcohol collected (heads + hearts + tails) or the hearts? If the 110 PG is the total alcohol collected, what is the abv at the parrot when you turn off the still and stop collection.

That is the hearts cut. The abv at the parrot when we make cuts is generally around 105 proof.

On 1/11/2024 at 3:17 PM, JustAndy said:

when you say "steam open full, dephleg open wide with dephleg temp reaching approx 200 F" does that mean water flow to the depleg is as high as it will go? And what is measuring 200F, the water out or a thermometer in the vapor path? 

Yes, flow to the dephleg as high as it will go. Thermometer is in the vapor path.

On 1/11/2024 at 3:17 PM, JustAndy said:

My guess is you aren't running the dephleg consistently and are turning off the still too early. So when you are running with higher steam/more heat/hotter incoming depleg water, you are getting less reflux and thus getting to a lower parrot proof earlier in the collection and then leaving more alcohol in the pot when its turned off.  

This is a possibility. The runs look like this: dephleg closed while collecting heads. Once we switch to main collection, dephleg is turned on very slightly, keeping vapor temp at around 190 for most of the hearts run. As vapor temp increases, dephleg is opened more until eventually the spirit flow goes down to a trickle. Then the steam gets opened up further until it is maxed out. Both dephleg and steam increase are done incrementally. Once the steam is full open and dephleg is wide open, we run until the proof at the parrot is about 105, but the final cut is made to taste.

Edited January 14 by Christopher ONeal
I forgot a word that changed meaning of a sentence.

[Christopher ONeal]

On 1/11/2024 at 10:41 PM, adamOVD said:

In addition with what @JustAndy said, are you dumping your tails into the next batch? Could you be running a batch inefficiently and then passing retrievable alcohol into the next batch, which is then run longer with more reflux towards the end of the run, retrieving the alcohol from the previous run? 

135P seems low through 6 plates if run in the conventional manner.

We were for a time collecting tails down to 10 proof, but that ended up being a total of about 15 gallons total. After factoring expected return (and actual return of batches with previous tails added vs not) the cost/benefit of the extra labor and utilities didn't justify capturing that, so we have not done that for a while.

[Christopher ONeal]

On 1/11/2024 at 3:47 PM, DeerHunter said:

Am I missing something? 528 gallons at 10.5% alcohol means there are 55.44 gallons of 100% alcohol going into the still. 110 proof gallons coming out would be 99.2% efficiency. I find that unlikely, or am I mathing wrong.

I am getting the same. We are slightly overfilling the stills from their official capacity (almost entirely up to the manhole, which is about a foot above listed max), so our batch size is closer to 550 gallons. And the 10.5% is an average. We have had as low as 8% and 12%. Those were outliers and our average is pretty representative, but I still think we are getting entirely too much product on these runs. But the numbers aren't lying. I am beginning to believe we have a consistent measurement error with our initial SG. I've been insisting on using a calibrated Brix meter (which we have), but I do not run the mashes. The worker who does insists his numbers are correct and double checked based on hydrometer/thermometer method.

[JustAndy]

The yield is all the alcohol produced (heads + hearts + tails). Having a variable sized hearts cut on a manually run dephelg still is a user operations issue.

You don't actually know the yield from each mash because you aren't running out the tails, and where you are making the tails cut is dependent on how the still is operated (heat input and dephelg water input & temp), meaning you dont know how much alcohol is left in the pot. You might also have a mashing issue but you won't know that unless you have actual yield data. To have good yield data you need accurate mashing SG, FG (which might need to be obtained via lab distillation), and volume. Then you can look at the expected mash yield vs the actual yield off the still. 

[Pofarmer]

You said the source of your grains didn't change, but did the grains change? It seems to me that you got into a new harvest season. Corn isn't just "corn". Characteristics vary from variety to variety and from growing season to growing season for the same variety. Are you getting a consistent grind? Are the starch and sugar levels the same? Is the moisture coming into your operation the same? Etc, etc, etc. We are currently working with an Orange flint that is uhm, challenging, from a grinding perspective. Yields haven't been quite what we expected so we're working on procedures. It's not impossible that you're getting an inconsistent feed stock.

[Kindred Spirits]

19 hours ago, Christopher ONeal said:

That is the hearts cut. The abv at the parrot when we make cuts is generally around 105 proof.

Yes, flow to the dephleg as high as it will go. Thermometer is in the vapor path.

This is a possibility. The runs look like this: dephleg closed while collecting heads. Once we switch to main collection, dephleg is turned on very slightly, keeping vapor temp at around 190 for most of the hearts run. As vapor temp increases, dephleg is opened more until eventually the spirit flow goes down to a trickle. Then the steam gets opened up further until it is maxed out. Both dephleg and steam increase are done incrementally. Once the steam is full open and dephleg is wide open, we run until the proof at the parrot is about 105, but the final cut is made to taste.

So just based on these responses, it doesn't sound to me like the still is getting run to the best of its ability. The main purpose of having a condenser at the top of the column is create more reflux and help you make tighter cuts.

The way you are currently running your equipment does not allow it to function as designed. You should have the condenser fully open to start, reach equilibrium, make your heads cut very slowly pulling off the concentrated heads, and then run out your hearts, once again slowly pulling them off to reduce smearing.  After that its up to you if you want to reach equilibrium again to try to extract some more of the higher or lighter tails, or just run out your tails for reuse, or just end the run.

[Christopher ONeal]

2 hours ago, Pofarmer said:

You said the source of your grains didn't change, but did the grains change? It seems to me that you got into a new harvest season. Corn isn't just "corn". Characteristics vary from variety to variety and from growing season to growing season for the same variety. Are you getting a consistent grind? Are the starch and sugar levels the same? Is the moisture coming into your operation the same? Etc, etc, etc. We are currently working with an Orange flint that is uhm, challenging, from a grinding perspective. Yields haven't been quite what we expected so we're working on procedures. It's not impossible that you're getting an inconsistent feed stock.

We have been on quite a merry go round regarding our corn, actually. We source everything from a local farm, and were getting some pretty bad batches in spring of last year. Lots of chaff, cobs, and even stones. Our head distiller started picking up the corn himself and spoke to the farmer (he continues to pick up the grain himself and we have developed a great relationship with the farm). We certainly started getting better corn in the late summer as a fresh harvest season came in, but we have been getting consistent starting SG numbers since then. We measure moisture content using Loss on Drying (LOD) method, and have seen little variation since summer.

[Christopher ONeal]

2 hours ago, Kindred Spirits said:

So just based on these responses, it doesn't sound to me like the still is getting run to the best of its ability. The main purpose of having a condenser at the top of the column is create more reflux and help you make tighter cuts.

The way you are currently running your equipment does not allow it to function as designed. You should have the condenser fully open to start, reach equilibrium, make your heads cut very slowly pulling off the concentrated heads, and then run out your hearts, once again slowly pulling them off to reduce smearing.  After that its up to you if you want to reach equilibrium again to try to extract some more of the higher or lighter tails, or just run out your tails for reuse, or just end the run.

The method you outline above is the method I was taught when first learning to run hybrid stills (not at this distillery). Our team had the designer of the still system we use out to show us how to run the stills in December of 2022. He actually had us run the still in pot still mode to collect the fores, then swap over to the column. There was never a separate heads collection done, and he advised running extremely tight (as close to 160 proof as we could) for the majority of the hearts run, and making a cut when the proof fell below 150.

We have adjusted the method in the intervening year (running the majority of the run at a lower proof, near 135, and making the tails cut at a much lower proof), based on the flavors we were tasting in the white dog and efficiency calculations I performed. Initially we were getting less than 70 proof gallons final product per ton of grain, which fell so short of industry standards that I had found in my research that we started playing with various parameters.

We have had many people in the industry, including some luminaries in the world of making and blending bourbon (I hate being cryptic about this, but I don't want to name names without their permission) complement our white dog as being exceptionally tasty. This has led to some pushback from our decision makers regarding major changes of method.

I would like to do a couple test runs with a separate stripping/spirit run, with the stripping done in pot still mode and the spirit run with 4 plates active in the column. The biggest challenge to that idea is that we are years away from knowing whether the whiskey we've been producing will be exceptional, average, or poor. Based on the feedback on our white dog we are certainly hopeful, but we don't know and that has kept us from making larger changes.

However, small changes that have resulted in a 25% increase in efficiency have perked them up as far as investigating new ideas.

[Kindred Spirits]

I think you would benefit from a full assessment of how things are being done, starting at the grains and mashing through the distillation process.

By being thorough on the processes documenting as much as possible you will be able to identify areas of improvement, or where you are doing great in the processes.

 

The way your still designer suggested running the still doesn't match conventional wisdom. I would love to chat with him on why he recommends running equipment that way.

[Christopher ONeal]

16 hours ago, JustAndy said:

The yield is all the alcohol produced (heads + hearts + tails). Having a variable sized hearts cut on a manually run dephelg still is a user operations issue.

You don't actually know the yield from each mash because you aren't running out the tails, and where you are making the tails cut is dependent on how the still is operated (heat input and dephelg water input & temp), meaning you dont know how much alcohol is left in the pot. You might also have a mashing issue but you won't know that unless you have actual yield data. To have good yield data you need accurate mashing SG, FG (which might need to be obtained via lab distillation), and volume. Then you can look at the expected mash yield vs the actual yield off the still. 

I apologize for being imprecise with my language there re: yield.

We did run out the tails a couple dozen times when we were recycling them, and with a 10 proof cutoff for tails we were getting an extra 15 gallons at ~35 proof (one of the things that genuinely has been confusing to me about these recent runs is that the tails we got previously represented approximately 10 proof gallons, us seeing a 20+ proof gallon increase without running into crazy tails flavors makes no sense to me). We don't have any info for tails in the recent exceptional runs, as we are no longer collecting them.

[SlickFloss]

I have some questions about your gauging. When was try last time your AP was serviced and calibrated? Do you use your AP for multiple product lines (i.e. finished liquors/cordials, flavored or sweetened products, finished whiskeys [wine finishes, other spirit finishes) etc. Do you follow the manufacturers reccomended cleaning protocol for your AP

 

As for your hydrometers, are they certified and accurate? How old are they? Have you integrity tested them against each other?

 

Using city water in the depgh is a very very very inconsistent input. Especially if the SOP is run it wide open. Colder media in requires less flow than warmer media, same flow rate of a colder media runs a deeper neg thermal load than a warmer one. It is possible to run a depgh too hard but I don't think thats the case here (you would notice this as a problem more in trying to maintain 100% reflux, but thats almost what it looks like you're doing)...... with that last parenthetical in mind is your still able to hold 100% reflux at all? 

 

As well if you adjusted your positive energy flow (steam) and not your negative flow (protocol for depgh at fully open at 200 f) there's an operational change that has changed the thermal dynamics of your system. May not be the case but it could be something to look at.

 

Finally, how's the water you cook with?

 

Cheers,

Slick

[SlickFloss]

On 1/15/2024 at 8:12 AM, Kindred Spirits said:

So just based on these responses, it doesn't sound to me like the still is getting run to the best of its ability. The main purpose of having a condenser at the top of the column is create more reflux and help you make tighter cuts.

The way you are currently running your equipment does not allow it to function as designed. You should have the condenser fully open to start, reach equilibrium, make your heads cut very slowly pulling off the concentrated heads, and then run out your hearts, once again slowly pulling them off to reduce smearing.  After that its up to you if you want to reach equilibrium again to try to extract some more of the higher or lighter tails, or just run out your tails for reuse, or just end the run.

Are you familiar with the design of the still they're running? It is other unique.... I haven't run one yet but I would really like to, essentially running one column off two kettles.... allegedly the kettles end up pulsing in a way, reciprocating vapor flow from one to the other into the base of the column. It makes sense, one kettle has vapor flow into base of column, eventually dropping subtly in steam pressure, kettle that want pushing through build up a little pressure and overtakes flowing into the column etc. etc. What I'm getting at here is not a very efficient still to run in terms of speed, and especially poor in terms of single pass off grain. IMO it would make so much more sense to run both of the kettles concurrently directly into the condenser as a stripping run with no reciprocating slow down and no fraction pulling or attempt to stack a very inconsistent stressed vapor stream, then run a finishing run. I think that the best way to run any still is variable based on inputs and product goals. For instance, the way you mentioned to run the still isn't how I would do it, especially given the mechanics of this specific system. I would make this assertion about any single pass run on grain so its nothing personal, but especially on this system. While I am playing devils advocate to a point here as I do understand the value of single passes in very limited instances, it would seem to me that running with no depgh for a stripping run would be a shorter run (no fractionation, no stacking of heads, no stacking of tails) requiring less steam (less time), less water (no variation of depgh flow) and less physical man hours on the overhead of the liquid produced. There are a bunch of reactions driven in the kettle that I believe point to better whiskey being made in shorter distillation runs. Especially on grain. Thats just me though.

Running like this would they perhaps able to run two strips (actually literally four kettles) in a single day? Overhead way down on that liquid. 

Obviously you can poke holes in this, more runs more OH costs come back more energy costs but I believe it is a more efficient faster way to process a bunch of cooks (production runs) and provides more consistency. If you stripped twice, charged with low wines, and then did a second finishing run, you can get more PGs through the run, you can operate with more precision on your cuts, and harvest larger fractions which can help when operators have problems managing smearing. As well, the end result of those two runs is much much much much more consistent for barrel maturation.

 

Millions of ways to skin a cat, and in terms of operating a single pass I don't disagree with your advice, but systemically I believe stripping and finishing is better for business, especially with the realities of this stills construction.

[Kindred Spirits]

49 minutes ago, SlickFloss said:

Are you familiar with the design of the still they're running? It is other unique.... I haven't run one yet but I would really like to, essentially running one column off two kettles.... allegedly the kettles end up pulsing in a way, reciprocating vapor flow from one to the other into the base of the column. It makes sense, one kettle has vapor flow into base of column, eventually dropping subtly in steam pressure, kettle that want pushing through build up a little pressure and overtakes flowing into the column etc. etc. What I'm getting at here is not a very efficient still to run in terms of speed, and especially poor in terms of single pass off grain. IMO it would make so much more sense to run both of the kettles concurrently directly into the condenser as a stripping run with no reciprocating slow down and no fraction pulling or attempt to stack a very inconsistent stressed vapor stream, then run a finishing run. I think that the best way to run any still is variable based on inputs and product goals. For instance, the way you mentioned to run the still isn't how I would do it, especially given the mechanics of this specific system. I would make this assertion about any single pass run on grain so its nothing personal, but especially on this system. While I am playing devils advocate to a point here as I do understand the value of single passes in very limited instances, it would seem to me that running with no depgh for a stripping run would be a shorter run (no fractionation, no stacking of heads, no stacking of tails) requiring less steam (less time), less water (no variation of depgh flow) and less physical man hours on the overhead of the liquid produced. There are a bunch of reactions driven in the kettle that I believe point to better whiskey being made in shorter distillation runs. Especially on grain. Thats just me though.

Running like this would they perhaps able to run two strips (actually literally four kettles) in a single day? Overhead way down on that liquid. 

Obviously you can poke holes in this, more runs more OH costs come back more energy costs but I believe it is a more efficient faster way to process a bunch of cooks (production runs) and provides more consistency. If you stripped twice, charged with low wines, and then did a second finishing run, you can get more PGs through the run, you can operate with more precision on your cuts, and harvest larger fractions which can help when operators have problems managing smearing. As well, the end result of those two runs is much much much much more consistent for barrel maturation.

 

Millions of ways to skin a cat, and in terms of operating a single pass I don't disagree with your advice, but systemically I believe stripping and finishing is better for business, especially with the realities of this stills construction.

I was under the impression this was a standard single pot still with a 6-plate column. I totally missed the two kettles part. Now I see its a Figgins style.

I 100% agree on there not being a best way to run all equipment, however there seems to be a number of people in the industry who were taught one way to run a still and they never change or question it.

I have never run a two-kettle system either, but the way you described the process makes sense. Do they have check valves in line coming from the kettles? or is it just based on the vapor flowing from each kettle?

I also like the "strip and finish" method for most grain spirits and this definitely seems like they could save time by switching to that method, not using the delph for the strips and tweaking its use for the finish runs. Having the better ablility to compress and make cuts on a finishing run typically results in a higher quality finished product. Single pass whiskeys have their place in the industry but a lot of times they suffer from excessive smearing into tails if not run correctly and can be oily. 

 

[SlickFloss]

7 minutes ago, Kindred Spirits said:

I was under the impression this was a standard single pot still with a 6-plate column. I must have missed the two kettles part. 

I 100% agree on there not being a best way to run all equipment, however there seems to be a number of people in the industry who were taught one way to run a still and they never change or question it.

I have never run a two-kettle system either, but the way you described the process makes sense. Do they have check valves in line coming from the kettles? or is it just based on the vapor flowing from each kettle?

I also like the "strip and finish" method for most grain spirits and this definitely seems like they could save time by switching to that method, not using the delph for the strips and tweaking its use for the finish runs. Having the better ablility to compress and make cuts on a finishing run typically results in a higher quality finished product. Single pass whiskeys have their place in the industry but a lot of times they suffer from excessive smearing into tails if not run correctly and can be oily. 

 

I could be mistaken but in original quote he mentioned its a 2000 liter figgins reciprocating, which Ive looked into in the past but have never run. I have sent Rusty some white dog samples he is lightly active on here but not a lot of media out or anything about them. If I am correct it is one of these

https://www.stilldragon.org/discussion/1728/usa-nc-sale-2000l-electric-figgins-reciprocating-still

additional info 

https://www.stilldragon.org/discussion/673/the-figgins-reciprocator

Possibly was or still is procured by Minnetonka 

https://www.mtka-bec.com/skins/skin_1/images/distillingequip.pdf

 

I don't believe it actually has active steam control to reciprocate I imagine that just happens from natural fluctuations in steam pressure of the two vapor streams competing for flow capacity. You can see what im referring to in some of the pics there's a Lyne arm that connects both stills with a T in the middle that feeds the bottom of the shared column. I have mentioned multiple times to Rusty that I would fly anywhere in the country to run one of these and pay for the OH and labor of prep and clean up and source materials of the runs to try one out but I haven't gotten a response back to that. Would meet you there to do it brother we could make a vid!

 

Cheers,

Slick