Proof lowered after design changes

[Shine0n]

My recipe is as follows
25lb sugar
12-14lb sf
15 gal water
1/3 cup bread yeast
I run a 2" pot 15.5 gal/thumper 7.5 gal to worm, NOW I just lengthened my arm to my thump keg and the proof has dropped from 160+ down to 140. I have not changed my recipe since I started it back in January. I have gotten less heads, less high proof hearts and the tails funky tastes comes much later on. IT used to be much higher proof so why just because I added some length (was 15" now is 30") would my proof drop so dramatically? I'm lost as of why! I did get a new burner that my keg sits closer to, I thought it was I heated up to fast on the first run on the new set up so on my 2nd run I heated up much slower and the same thing happened...140 proof!
At 100 proof I'm sure they are into the tails by then but has no wet dog/cardboard smell and tastes just fine right off the still. 90 proof the cloudy stuff sets in just as before all this but very little wet dog smell. WHAT gives?
Before the alteration I would hold 160 for a solid gallon before any drop and now every jar is lower and lower but all smell and taste good.
Anyone have a clue of why this would happen?

[nerdybrewer]

Any active cooling on the arm?

[StillLearning1]

Multiple washes coming out lower proof? Maybe your ferments started to stall for some reason?

[Kareltje]

NOW I just lengthened my arm to my thump keg and the proof has dropped from 160+ down to 140. I have not changed my recipe since I started it back in January. I have gotten less heads, less high proof hearts and the tails funky tastes comes much later on. IT used to be much higher proof so why just because I added some length (was 15" now is 30") would my proof drop so dramatically? I'm lost as of why!

Please be more exact. Less heads, less hearts and less tails? So in total much less alcohol????
I do not know much about thumpers, I hope to learn here some things.
But your math must be wrong somewhere, or your description is not precise.

I guess you have a longer heart of less proof. Am I correct?

[HDNB]

did the angle of the lyne arm change from up to the thump and is now down to the thump?

(passive reflux changing direction?)

try insulating the lyne, the longer one will be sending less heat to the thumper. heat into the boiler is going to change the abv somewhat too.

[corene1]

I have to agree with HDNB . If the change happened after the modification the longer tube would seem to be the likely culprit. I would insulate it as much as possible and see what happens.

[Shine0n]

The height has not changed just the horizontal length over to the thump keg.
Now that I have a new burner, the keg sits about 3" closer to the flame, the spread on the burner output is a bit wider as well. I did that so that I wasn't loosing as much heat and wasting propane.
I said in op that I had less high proof hearts. IT starts out at 140, next heart jar is 135ish next is 130.

After my fores I used to have 2 maybe 2.25 quart of heads before I got into the heart, now I have 1 quart and the chemical smell is gone. To me is significantlyless heads.

Kareltje, correct! Total collection is down 3/4 of a gallon.
Even though the proof is not holding steady as it was before, it's dropping every jar now. The the taste is fine, im just lost on why the proof of my distillate is lower now vs then.

I will insulate my keg and lyne arm and thumper since now fall has came in Va.
Thanks

[Andy Capp]

Keg sitting closer to burner sounds like the culprit. Too much heat would cause smear through your run. That's probably why your getting less of everything.
Try backing off the heat and see how that goes.

[still_stirrin]

Keg sitting closer to burner sounds like the culprit. Too much heat would cause smear through your run. That's probably why your getting less of everything.
Try backing off the heat and see how that goes.

+1.

I thought exactly the same thing. More heat -> smearing over a wider range. Plus, you came online quicker too didn't you?
ss

[Shine0n]

SS, Yeah I'm up to temp alot quicker than before. Not sure if you read in op that on the 2nd run I slowed heat up time quite a bit. That didn't make no significant difference,
I haven't had the feints that I had before so I'm putting a lot less into my pot. I'm as we speak pulling fores and will check abv.
I'm getting less but the quality is there imo. The loss of abv is what's confused me.
Just checked and my fores are 150, I slowed down even more and that has helped to a degree.

[Mikey-moo]

was 15" now is 30"

In addition to the higher heat, could the early heads be pooling along the length of this longer arm and smearing further into hearts that way?

[Shine0n]

There a very slight downward slope towards the thump keg so I Don't think anything is pooling. That was intended in the build to make sure all would go towards the thumper. Even the crossover from the riser coming from the thump to the worm has a downward slope (very little)
I think since the new burner heats faster and sits closer that was my problem. I heated up very slow this morning and am running extremely slow at the moment my abv is back up to 160.
I do still plan on insulating my rig for the winter as I run in an uncontrolled environment, pot, lyne arm, thumper.
Thanks all,
Shine0n

[HDNB]

I haven't had the feints that I had before so I'm putting a lot less into my pot.

ummm...dontcha think this may have something to do with it?

[Shine0n]

This is why I keep reading and staying active on HD! Just simple things such as a new burner, longer lyne arm made me learn how to drive my rig all over again. And thanks to all who gave their opinions to make me check different things to come to a positive conclusion. MUCH appreciated

[Shine0n]

I haven't had the feints that I had before so I'm putting a lot less into my pot.

ummm...dontcha think this may have something to do with it?

Possibly so
I only had 1/2 gal of feints I put in the thumper along with some wash this morning it probably has helped.
I'm sure that the heat input was also to blame.

[Kareltje]

I have been chewing on the problem. Thought about the cooling in the lyne arm, missed the higher burner.

I thought about a observation I made recently: slowly stilling with a wide condenser and with a narrow condenser made a difference of almost 15 %ABV (74 against 89 %ABV). The wide condenser has no resistance when I blow in it, the narrow needs a force of about 8 cm water to blow.
I concluded that the narrow condenser keeps the vapour longer in the riser, resulting in more reflux.
Maybe that is a point in your longer arm too?

But as I see now you have at least 4 suggestions for the cause. Time to experiment!

[Shine0n]

The next 1/2 quart will make 2 gallons. 1st gallon ranges from 160 to 155.
2nd gallon is 155 to 150, I'm hoping to get another 1/2 gallon before I run hard and collect down to 30% for my feints.

[Shine0n]

I just pulled the last pint and now the decline has started. It was 142 proof.
I'll collect another pint or 2 then see if the wet dog smell starts to comes through or not. On the last 2 runs the tails came later than they have been so I'll keep my fingers crossed I get a little bit more