Yield Issues on First Whiskey Distillation

[billop01]

I searched the forum and didn't find anything exactly my case, but please redirect me if something that will cover my questions has already been posted:

I've just finished setting up (cleaning, etc) my new 8 G SS/copper pot still. Ran a cleaning sugar wash last weekend and everything went as expected: Started with ~10% in 3 G ferment, heads came off at ~75% ABV, collected until tails were about 20% ABV, had about 2.0 L collected (not for drinking, just for cleaning).

My friend fermented a whiskey wash for me since he was brewing some beer alongside it (50% corn, 22.5% 2row malt, 22.5% rye). I don't have all the details of the mash, but extraction/conversion seemed ok and fermentation proceeded vigorously/steadily.

SG - 1.060
FG - 1.010
Volume - ~6 G
Max Yield ~ 1 G at 40% (obviously not expected to collect the full amount)

Since I was only planning on a single run, I ramped the temp of the wash up very slowly, reaching ~175 F in the kettle after 1.25 hrs. Started collecting at a slow drip (head temperature ~155F) until 150 mL foreshots collected, then switched to heads collection. Heads smelled good, viscous and good bead of bubbles when shaken. However, the first ~350 mL fraction of heads was only about 60%. This wasn't too concerning, but subsequent fractions decreased and by the time I had collected about 1.2 L, was down to 30% and head temperature was ~200 F (kettle temperature was now about 210 F). Collection never past a moderate trickle; collected for 3.5 hrs.

No excess alcohol smell, so I don't think it was inefficient collection in the condenser. I have a recirculating condensor set-up (with a pond pump) that was kept stocked with ice.

Exterior temperature was -5 degrees C.

any thoughts or advice is greatly appreciated.

[NZChris]

Regardless of what various friends, forum posters, youtubers and HBS proprietors tell you, single runs through a simple pot still don't get close to the quality of double runs through the same equipment.

My research told me not to expect to make good product on a single run, so I started with a fermenter capable of providing four still charges of ferment. Thirty years later, it is still my most used fermenter.

[HDNB]

1.06-1.01 = .05

.05 Sg/.0074 = you had about 6.75%

6.75% alcohol x 6 gallons = .4 of a gallon ...or 1 gallon at 40%....exactly what you got.

and what Chris said +1

[still_stirrin]

Excellent posts HDNB & Chris.
This question with these 2 posts should be “stickied” for all new distillers.
It should be added to Cranky’s Spoon Feed links.
It is that important of a message.
ss

[billop01]

Thanks so much for the replies. Point is well taken Chris, will have to see about bumping up fermentation capability to get more wash volume for multiple first stripping run charges.

Note that I recovered 1.2 L of 40%, so about a third of what I expected. I might not have been clear on the combined proof of the 1.2 L.

[HDNB]

ahh..i see now.

the last 12 degrees of boil temperature you had left prolly held about 1.2L at an average of 20 % ish feints.

dunno where the rest went.

edit: Fak, i gotta work on reading comprehension. i see now the kettle was at 210, so apparently you were done.

but i think we all agree, the math ain't mathing out right.

[NZChris]

I'm not sure if I understand your numbers correctly, but my rough calculation has it that you only collected barely over half of the available alcohol.

22.8l @ 6.56% = 1495ml alc.

150ml Foreshot @ about 60% = about 90ml alc.
350ml @ 60% = 210ml alc.
1200ml @ 40% = 480ml alc.
Total = 780ml alc.

[billop01]

Thanks Chris!

[zapata]

Just throwing out some possible beginner errors.
Using an alcometer for spirit and a hydrometer for washes?
Temp correcting all readings?
Accurately measuring volumes?
Calibrated thermometers, for both correcting gravities and reading the pot? Or at least measuring their offset and accounting for it.
10% variation in all of these is possible, and effects add up.

[NZChris]

That still has a very small condenser. If you overpowered it, that might account for losses.

Leaks?

How accurate is the bottom thermometer?

[billop01]

Thanks folks

Zapata, all corrected and using the right types of hydrometers for the tasks (how would one even get the corresponding values from the wrong meters); volumes measured using volumetric glassware (grad cylinders)

As for the thermometer questions, best I can say is that they are relatively new and came calibrated. I did a water run as part of my cleanup and the head thermometer was bang on 100 C. The kettle was a bit over, so there may be some offset there.

I was worried about the size of the condenser, so that’s why I tried to keep flow so low.

No leaks have been noted in any runs.