I’m hoping a few of you might help me troubleshoot a failed attempt at a single malt whiskey. (And apologies for the length, but don't want to leave anything out.)
Up to now, my experience has been mostly with sugar-based neutrals and rums. I have around 30 distilling runs under my belt with no issues whatsoever. While this is my first all-grain whiskey, I have made beer, and bourbon from a kit (which included some sugar, so not ‘all-grain’).
This being my first all-grain whiskey attempt, I kept it simple – 14 lbs of Briess 6-row malt.
While I’m including my full notes below, a summary:
I use a Digiboil 35L/9.25 gal brew kettle, and have the malt pipe with a false bottom. So mashed in that, using the beer-making process (Vorlauf during mashing, sparge, boil before pitching yeast) and largely everything went according to expectations.
The only issue I had during the mashing process (14 lbs of malt in 5.5 gallons of water) was that I might have ground the malt a little too fine – while using a recirculating pump to bring wort to the top of the grain bed, I had to stir every 5-10 minutes to loosen up the bed at the bottom to allow the wort to flow through. Also I had a little bit of an issue maintaining proper mash temp for the same reason, though it generally was somewhere in the upper 140s F. But after about 3 hours of mashing, I did a starch test, and it appeared to show full conversion.
After sparging 1.5 gallons of hot water through the elevated grain bed, I ended up with about 6 gallons of wort, and pitched 7.5 grams of properly hydrated baker’s yeast at 95° F. Airlock, oyster shells and aquarium heater (with InkBird controller) were added.
My starting gravity at yeast pitch was 1.065 (adjusted for temp). Temperature was held at 85° F. Two days later my gravity read 1.007 (unadjusted for temp), and three days later 1.003). At this point I left town for a little over two weeks, so turned off the heating source, and it sat and settled in my 68° F basement.
When I returned I attempted to strip it, using the same kettle at 2400W with a shotgun condenser. (See attached photo.) However, the temperature in the kettle rose well past the temp where I’d expect distillate to condense; I got to 181° in the kettle, but the temperature at the head only read 76°. Sensing an issue, possible blockage (I included a small ball of copper mesh between the two reducers), I shut down.
I checked the setup, and not seeing any blockage, ran it again, this time at 1900W. Thinking there might be an issue with the kettle temperature gauge, I let it go, and when it hit 200° F, hot wort started spewing through the condenser.
It appears as if there was no alcohol in the wort.
As a post-mortem, I checked my equipment – all joints were tight and sealed, and there was no blockage. The two temperature gauges (at the bottom of the kettle, and in the riser) are accurate. The wort itself was super sour, and the pH came in right around 4.0. Theory 1: There was no starch conversion, and the drop in gravity was just particulates falling out of suspension. However, I mashed for 3 hours, constantly mixing and stirring and circulating the wort, and a starch test showed conversion. (That said, I’ve only done a starch test a few times.) And the sourness of the beer after fermentation suggests it did ferment. Theory 2: The yeast was somehow dead/killed, and again the drop in gravity was from particulates settling. But I’ve used this yeast before, and it was properly hydrated.
At this point I’m ready to make a second attempt, but hoping a few of you can give this a read and let me know if there’s anything glaring that I’m missing or screwing up.
Thank you!!
Full notes: Mashing:
•Started Tuesday, Sept. 6.
•Heated 4.5 gallons of water to 170.
•Milled 14 lbs of 6-row malt. (The volume of malt looks like a lot comparative to the water. Might need to use less grain per the water if volume gets high.)
•Added one tablespoon of pH 5.2 buffer.
•Started adding grains at about 5:30.
•Added another gallon of warm water about half way through the addition of grain.
•Managed to slowly add in all 14 lbs of malt. The drill-mounted stirrer worked ok to mix in the grains, but the paddle was necessary to keep the false bottom clear of clogs.
•At about 8:40 pm an iodine test showed full conversion, so the malt pipe was lifted to allow the grains to drain. (Thoughts as to why it took so long: density of the mash (with considerably smaller particles in 14:5.5 grain to water ratio), and a temperature in the mash that wasn't quite at optimal range for alpha amylase. (While the kettle temp at the bottom was 150, the temp in the mash itself generally stayed in the mid-140s.).)
•At 10 pm, 1.5 gal of boiling water was sparged over the grain bed, and left to drain overnight.
•In the morning, we had just under 6 gallons of wort at 1.070 @ 70°F.
•Reheated wort at 10:45 am, and let boil for 1/2 hour.
•Preparing 7.5 g of baker's yeast with a little over 9 g of GoFerm. (Heated 8 oz of distilled water to 100°F, and a controlled water bath to 90°F... Added GoFerm, allowed to rest for 10 minutes... Floated yeast on top of the GoFerm solution, allowed to sit in the heated bath for 20 minutes... After twenty minutes, agitated the jar, and a short while later added like 2-3 oz of wort.
•While preparing yeast, introduce wort chiller to crash cool the wort. (This brought out a thick foam - don't know if it will affect the final product, but we'll find out! (Might try to run the wort through a strainer when emptying into the fermenter.).)
•Also, removed the boiler jacket to speed up cooling.
•When the boiler temp reached 125°F, added 1 gallon of chilled, distilled water.
•At 110°F, removed the wort chiller and transferred the wort to the fermenter (allowing to splash from height to aerate).
•Yeast was pitched at 95°F, and oyster shells, heater and air lock added... Gravity at pitch was 1.065 (corrected), and pH was about 5.4... Note, I did NOT add nutrients, as barley should be able to supply those. If it seems to struggle than I'll add a half dose after 48 hours. Fermentation:
•Didn't see much airlock activity in the first 48 hours. On Friday, Sept. 9 at noon, however, I took a hydrometer reading, and it had already fermented down to about 1.007 SG. So must have a tiny air leak somewhere.
•By the following Monday (Sept. 12) we were down to 1.003 (adjusted). Distillation:
•Let this guy sit for two and a half weeks, owing to work.
•Stripping on Thursday, Sept. 29; boiler started at 10:15 pm.
•Wort smelled exactly like beer - a good sign!
•At about 11:20 pm, boiler is at 181° F, but head only reads 76 ° F....
•Had to shut down. Boiler temp reached 194, and head temp barely budged. What's more, after shutting down, head temp slowly increased to about 100°, while boiler temp dropped. I allowed the still to cool to room temperature before turning off my coolant pump and removing the lid.
•There appears to have been some foaming, but it doesn't look like it rose more than a couple inches above the wort level. Could this have trapped alcohol beneath it? Doubtful. Distillation (Attempt 2):
•After checking the column for blocks, applied 1900W of heat at 8:34 pm (Friday, October 7).
•I let this go for a while; temp at the head never got to 90°F, but when the boiler exceeded 200° F, hot wort started gushing it out the product condenser. So there was no alcohol on it. Where did it go??Attachments
Did you have the water through the condensor?
Edit re read did you have sufficient water?" you can pick your nose and you can pick your friends; but you can't always wipe your friends off on your saddle" sage advice from Kinky Friedman
How tight did you pack the copper scrubbies in the riser? I suspect you got a plug when the mash puked (from the heat input).
Sugar washes don’t carry grain particulate and proteins like your all-grain mash did. So, while the sugar wash would run without puking, the grain mash did puke. The scrubbies soaked the puke and plugged the riser, increasing pressure in the boiler which in turn caused the flood of mash over the top.
If you leave more headroom in the boiler to allow a boil up (froth) of mash, you shouldn’t experience the flooding. But, I also suggest loosening the packing, as it doesn’t need to be tight at all. You’re just trying to get contact betwwen the hot vapor and the copper foil to help with sulfur reduction.
ss
p.s. - Don’t “watch the thermometer”. It’ll just confuse you. Potstills cannot be operated by temperature, so don’t get mesmerized by the fancy big dial. Tape over it … and run by touch and output rate.Last edited by still_stirrin on Wed Oct 12, 2022 1:48 pm, edited 1 time in total.Attention new distillers: Cranky's spoon feed info
My LM/VM & Potstill: My build thread
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My 5-grain Bourbon recipe: Special K
Yes, just to the right in the photo is a 35 gallon trash can of water that I pump through the condenser. I can tell if there's any interruption in the flow, and there wasn't.
The packing was very, very loose, and I used the same packing in the same configuration several times before (my last couple of rum strips). On the first attempt the first thing I considered was that it was plugged there, but on checking it was still very loose, and there was no indication that foaming/puking reached even the lid of the kettle, much less the riser. (Like 1' of copper mesh roll, see photo.)
I had about 6 gallons of wort in a 9.25 gallon boiler, so there was plenty of head room.
I really think the issue is somewhere in the mashing or fermenting process, but thank you guys for working me through this!
[Edited to expand response.]Attachments
I think you just need to run it a bit longer for the temp to rise up into teh riser... Did you feel it moving up as the boiler came up to temp? Can you hear it boiling?
Cheers,
j————
i make stuff i break stuff
water into whiskey into water
just getting started in home distilling - been drinking for decades
16g copper pot still, 10l alembic, and a column or two
————
The alcohol is still in the boiler waiting for you to try distilling it again.
10% alcohol boils at around 200f That's when it boiled over and puked.
Try it again but next time, turn the power down just before the boiler temp hits 200F.
After the boiler gets over trying to puke, you can gradually turn the power up.
The good news is your mash process and fermentation is normal.
The bad news is your running too much power and causing the boiler to puke.
To answer both Shady & Jonny:
In all my prior stripping runs (rum & sugar washes), with similar alcohol content, this still configuration followed the exact same pattern: at a little over ethanol's boiling point (say 176-177°F), I see my first drips of foreshots. Riser temperature is generally somewhere around 110°. I hit a steady stream with the boiler in the low 190s, and the riser temperature in the 170s. Further, the boiler temp rise slowed considerably over time in my prior runs as ethanol and such vaporize above 174° and draw heat out of the boiler.
In my first attempt here, I hit 194° in the boiler, and only 80° in the riser, when I shut down. In the second attempt, I was at 202°/88° when it puked. In both instances the boiler temp was a straight line of temp to time.
So my question to Shady's suggestion: would a grain wort act that differently from molasses/sugar washes? Shouldn't some of the alcohol be boiling off at lower temperatures than 200°?
With respect to power, I ran at 2400W the first time, and 1900W the second time, which is comparatively underpowered to many of you. But maybe there's an issue there. (Unfortunately, being a brew kettle, I can't adjust beyond full blast with one or both heating elements. I just set the target temp to 212°.) My next big move is building out a 15.5 gallon keg for stripping, so maybe I need to hurry that up....
Compared to a sugar wash, a mash is "much more likely" to foam up and cause a puke.
Alcohol can't boil off until it's being heated to whatever temp it boils at.
Shady's got this. Fermentation byproducts from an AG (caution, extremely hypothetical wild ass guess follows) create a beer that has more (xyz??) that has higher surface tension that creates an opportunity for more air and bubbles to get trapped as you approach boiling temps. Those bubbles are the foam that boils over and pukes. The perfect analogy is boiling water vs. boiling water with pasta.
When you boil water, the surface tension is such that the steam bubbles rise to the surface and immediately pop - no boil over. But now you throw a handful of pasta into the water, and if you don't regulate temps, foam and boil-over. What causes the problem in pasta (and rice) is the starches are extracted from the grains. In a fully fermented beer, starches shouldn't be a problem. But some compounds are causing the same issue.
Big picture, when distilling an AG, either always fill the boiler with less volume than a wash, or watch your temps like a hawk when you get to the point you will see distilate.
Best, Drifter
Feel all along the vapor path as it comes up to temp to see where the heat gets to and how fast it’s getting there. I do this with all runs. It’s a very good indicator where a thermo is only one spot.
I usually get a puke on an AG strip if i’m not careful. A couple/few dollops of evoo or butter helps that too. I’ll also dial power way back as I come up to temp and take fores very low and slow for about an hr which helps prevent a puke.
Cheers!
-j————
i make stuff i break stuff
water into whiskey into water
just getting started in home distilling - been drinking for decades
16g copper pot still, 10l alembic, and a column or two
————
Not much left to say after this.
Your riser is so short if your still decides to puke, you just don’t have any real time to react before all hell breaks loose.
You’re mashing and fermentation protocols sound legit and I’m almost positive you had at least a 6-7% distillers beer.
jonnys_spirit has also given great advice. Get to know your still physically
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feel along your riser to determine when you should start turning down power. Basically once that top reducer starts to get hot you’re going to be ready to roll.
Looks like you’ve got some 1.5”-2” reducers?? Down the road see if you can’t get a sanitary tube as a replacement and add a sight glass just above your boiler. It’s saved me a time or two.
Have fun and stay safeFreedom had been hunted round the globe; reason was considered as rebellion; and the slavery of fear had made men afraid to think. But such is the irresistible nature of truth, that all it asks, and all it wants, is the liberty of appearing.
-Thomas Paine
I'm of the same opinion as Shady and Johnny. With AG you have to really pay attention to the FEEL of the components of the still and predict when to reduce the heat input to prevent a puke. I think you missed it.
It happens very quick. Especially with an all SS rig where the heat transfer isnt as efficient. The boiler temp will hit boiling temp while the top of the riser will still be under 100f. Then, before you know it it's puking and the temp on the top of the riser finally starts to spike.
I still get bit on occasion, but a sight glass between the boiler and the riser can help you see when to kill power, calm the boil, then gradually increase the heat to bring the output to the rate you want it.
All is not lost. Verify the calibration of your thermometers,then tape over them, pour everything back in the boiler, and use your senses. Listen, feel, and smell. You can tell when it's time to turn down the power without a thermometer.
Don't try to rush the boil. For one, it'll bite you in the ass, and two, you're cheating yourself out of magical chemical reactions that happen as the temperature slowly rises in the boiler.Use all your senses, and its not that hard. You just have to pay attention.
Procrastinate, you'll make better whiskey.
This is all very helpful, thank you everyone.
Fortunately, I have a number of pieces I can add in to increase the riser.... It's actually 2-3" reducers, and I have both a 3" cylinder tri-clamp sight glass, and a 12x3" spool I could use.
Unfortunately, I currently don't have any means to modulate the power input - there a 500W element, a 1900W element, and power is applied until it reaches a preset temperature. So even if I was to step up the target temp one degree at a time, it would cycle the power input on and off to maintain that temp. No good.
So it sounds like I'm going to build an SCR. (Was going to get there eventually anyway...)
Anyway, thanks again, all. This has been really informative.
Don't give up yet.
Heat with 1900w until the still pukes.
Then switch to 500w and wait awhile, before turning the power back to 1900w.
If it pukes after turning the power up, turn it back down and wait a little while and do it again.
After puking a couple times, the mash most likely will settle down and quit puking.
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Another option is to add a de-foamer such as lard, butter, vegetable oil or better yet.
Get some anti-fart Gas-X's its main ingredient is simethicone.
Keep some rice hulls on hand in case this happens again, if start having trouble during your recirc mix in a big handful of the hulls and get back to it, that will reduce your stress immensely. Start loosening your grind up a few thousandths until you get it running free, measure that gap and use it for all your malt in the future.
Based on your gravity readings your yeast did their job fine. Taste your beer before you distill, you will learn a lot from it. If it's sweet you have a ferment issue.
On the temp bit, my column stays at room temp until a few minutes before distillate starts to flow. It's normal, physics happens. Pull the packing out of the column on your strip runs, spirit don't puke so toss it in for the spirit run. Once you have your strips figured out you can add it back if you feel it necessary.:)
Post time 2022-10-12 21:14:58
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