Proof bump when using a thumper

[MooseMan]

Today I ran only my second run using a thumper, and have a question for those who use them regularly.

On both of my brandy runs with a thumper, I've had almost the entire run at 80-84abv, with evidence of tails coming in the high 60's-70's.
First run I charged the thumper with apples and water, second one, wine and fruit syrup.
I love the thumper for it's ability to boost flavours but the proof bump is not something I really want, as I don't want to age product at nearly 80abv or have to immediately add water to my product for aging.

So, what techniques do you guys regularly employ in order to keep the proof at a level that suits you on a spirit run?

[Bolverk]

I love thumpers

Charging the thumper with just enough 0 abv liquid (water, juice, etc) to cover the spear will have the least affect on the over all abv of the spirit. But you are still going to get a proof thats higher than a single pot/stripping run. The benefit is that the thumper will act as a tails trap and extend your hearts cut a bit allowing you take off a bit lower and lowering your final product abv.

[SW_Shiner]

Either one and done it, or strip way lower. The only real way to decrease the exit abv, is to decrease the input abv. IIRC, scotch, or a similar whiskey is stipped down the the same abv that the wash was originally. You get the benefit of a strip run, but also the proof of a one and done.

[haggy]

MooseMan,

Some operating conditions that can result in a high abv ( 80%-85% ) product:

1. High abv ( >20% ) in both the pot and the thumper

2. Reflux in the exit lines of both pot and thumper
insulation might help

3. Low % fill of the juice ( with alcohol in it ) in the thumper
allows more wall area for reflux on the thumper walls > higher abv
insulate pot and thumper walls could help

4. Thumper dimensions - fat or skinny - amount of wall area exposed
allows more wall area for reflux on the thumper walls > higher abv

5. You stopped too soon - 60-70% abv - maybe it was tails but
many stillers run down to 40-45% out the thumper spout
and that way the average product abv will go down

Are you doing some of these operations?

Give me some details of your exit lines , the pot and thumper dimensions and
charge ( gal and abv ), and the watts used and I can check your run on the HD Calculator.

Haggy

[Yummyrum]

For Rum , I like to barrel higher anyway . But say I put 10litres @ 82 % into barrel , I only have to add 1litre of water to bring it down to 75% . I don’t think it has much effect on flavour. Especially as I’ll be adding a whole lot more to bring it down to 40% for drinking and then add a cube of ice .

[Yummyrum]

5. You stopped too soon - 60-70% abv - maybe it was tails but
many stillers run down to 40-45% out the thumper spout
and that way the average product abv will go down

Haggy , for me , I find anything below 70% is disgusting tails . No way I’d dilute with any if it .I do collect it for recycling though .

[LWTCS]

Everything yummy said,,,,,imo.

[PalCabral]

With brandy, you really want to avoid as much dilution as you can. I dilute by one abv per month so it will take a while before reaching drinking abv, started at 76%.

Interesting thread, Moose, I am also concerned about coming off the spout high and landing my hearts cut high. My copper dome pushes that abv up. I am thinking of adding some fermented wash with the low wines for the spirit run to see what that can do.

[adamf]

I love thumpers

Charging the thumper with just enough 0 abv liquid (water, juice, etc) to cover the spear will have the least affect on the over all abv of the spirit. But you are still going to get a proof thats higher than a single pot/stripping run. The benefit is that the thumper will act as a tails trap and extend your hearts cut a bit allowing you take off a bit lower and lowering your final product abv.

+1
Yes, you don't need much liquid in the thumper for it to do it's work.

[adamf]

With brandy, you really want to avoid as much dilution as you can. I dilute by one abv per month so it will take a while before reaching drinking abv, started at 76%.

Interesting thread, Moose, I am also concerned about coming off the spout high and landing my hearts cut high. My copper dome pushes that abv up. I am thinking of adding some fermented wash with the low wines for the spirit run to see what that can do.

After testing some brandy (Apple) runs with only Apple wine in the thumper, I'm going to stick with a double distillation for Apple brandy (Calvados).
The thumper results were ~86 %. The double distilled, 78%. Final results, proofed down to 96, 48% (white) favored the double distilled method for overall drinking quality.

adamf

[MooseMan]

MooseMan,

Some operating conditions that can result in a high abv ( 80%-85% ) product:

1. High abv ( >20% ) in both the pot and the thumper

2. Reflux in the exit lines of both pot and thumper
insulation might help

3. Low % fill of the juice ( with alcohol in it ) in the thumper
allows more wall area for reflux on the thumper walls > higher abv
insulate pot and thumper walls could help

4. Thumper dimensions - fat or skinny - amount of wall area exposed
allows more wall area for reflux on the thumper walls > higher abv

5. You stopped too soon - 60-70% abv - maybe it was tails but
many stillers run down to 40-45% out the thumper spout
and that way the average product abv will go down

Are you doing some of these operations?

Give me some details of your exit lines , the pot and thumper dimensions and
charge ( gal and abv ), and the watts used and I can check your run on the HD Calculator.

Haggy

Thanks for all the input guys, interesting views.

Haggy, some of the info;
100l Boiler charged with 70lts of low wines at 30abv
30l Thumper charged with approx 15lts at 5abv

Line from boiler to thumper very well insulated with neoprene sleeving, probably 95% efficient
Thumper walls insulated with reflectix, probably 60% efficient.
Heavy fleece on thumper lid, probably 60% efficient.

Majority of run power after fores, 3.1kw.

[PalCabral]

MooseMan,

Some operating conditions that can result in a high abv ( 80%-85% ) product:

1. High abv ( >20% ) in both the pot and the thumper

2. Reflux in the exit lines of both pot and thumper
insulation might help

3. Low % fill of the juice ( with alcohol in it ) in the thumper
allows more wall area for reflux on the thumper walls > higher abv
insulate pot and thumper walls could help

4. Thumper dimensions - fat or skinny - amount of wall area exposed
allows more wall area for reflux on the thumper walls > higher abv

5. You stopped too soon - 60-70% abv - maybe it was tails but
many stillers run down to 40-45% out the thumper spout
and that way the average product abv will go down

Are you doing some of these operations?

Give me some details of your exit lines , the pot and thumper dimensions and
charge ( gal and abv ), and the watts used and I can check your run on the HD Calculator.

Haggy

Thanks for all the input guys, interesting views.

Haggy, some of the info;
100l Boiler charged with 70lts of low wines at 30abv
30l Thumper charged with approx 15lts at 5abv

Line from boiler to thumper very well insulated with neoprene sleeving, probably 95% efficient
Thumper walls insulated with reflectix, probably 60% efficient.
Heavy fleece on thumper lid, probably 60% efficient.

Majority of run power after fores, 3.1kw.

Always interesting to understand how others are running. I have found that I get better results with low wines at or below 25% ABV, when it comes to Whiskey that is. My Apple Pomace Brandy low wines were at 25% also. Haggy helped me with calculating the reflux impact of the copper dome, much appreciated, his pointers above make perfect sense to me and my situation. With 10L of undistilled wash I will get down to 22-23% ABV. Experimenting with that to see if that changes how hot I get.

[haggy]

MooseMan,

I put your run on the HD Pot and Thumper Calculator and got fairly close to your results. Then I played with various set points and found an easy way to lower your product abv.

First your current operation.
After the heads, I got about 81% abv product coming over from the thumper for about halfway into the run then slowly dropping down to 69% abv after 20 liters were made. So about 15 liters of hearts made at almost 80% abv.

A concern of the run was the fill of the thumper, it got up to 30 liters at the end. So watch out for this. Did you check the thumper fill at the end of the run?

Here is a printout of key variables during the run. The last partial column on the right is the Thumper Fill - 30L at the end. The column of Thumper ABV% is the product out the spout, next is the Cumulative ABV %. Also, you see that the vapor out the pot is greater than the vapor out the thumper, that is why the thumper fills.

image.png

What can be done to reduce the ABV% of the product?

I looked at several changes to the input data and did not see much change in the product ABV. Then I tried this:

Put 15 L of VERY HOT ( 75C ) water in the thumper to start with.

This will reduce the time it takes for the thumper to start boiling ( 12 min vs 33 min ). Which reduces the amount of 79% to 69% abv stuff coming over from the pot. So you end up with a lower thumper liquid abv when boiling starts and a lower product vapor abv.

Below next is that key variable ( thumper liquid abv ) during the run for your current run and next for the VERY HOT water run. You see that the VERY HOT water case, the Thumper Liquid ABV% is initially about 10% lower in the run then the difference reduces down to zero and at the end is a little higher. So the thumper vapor will also be lower for most of the run.

image.png

image.png

And last is a printout of all the key variables of the VERY HOT water run. The Thumper %ABV out the spout is about 5% to 4% lower the first half of the run. If you could start with 20L of VERY HOT water in the thumper. the thumper product would have even a lower abv. But you have to watch out for overfill of the thumper.

image.png

And maybe it is mainly the heads abv that is being reduced. The hearts abv might not be reduced as much. So, try this and see if it gets the lower abv that you want.

Haggy

[shadylane]

Today I ran only my second run using a thumper, and have a question for those who use them regularly.

On both of my brandy runs with a thumper, I've had almost the entire run at 80-84abv, with evidence of tails coming in the high 60's-70's.
First run I charged the thumper with apples and water, second one, wine and fruit syrup.
I love the thumper for it's ability to boost flavours but the proof bump is not something I really want, as I don't want to age product at nearly 80abv or have to immediately add water to my product for aging.

So, what techniques do you guys regularly employ in order to keep the proof at a level that suits you on a spirit run?

"On both of my brandy runs with a thumper"
I think using a thumper was a mistake. It's not the traditional way of making brandy for a reason.
Thumpers will raise the ABV but compared to strip and spirit runs don't do as good job of cleaning up the character.

[30xs]

Maybe a better way to lower would be say 1/2 wash and half strip in the boiler starting out with a lower proof potential? Never ran a thumper run, but just going from what I’ve pulled from reading. Wouldn’t diluting the ABV of a strip with fresh wash both lower the output proof and increase the flavor potential?

[MooseMan]

Today I ran only my second run using a thumper, and have a question for those who use them regularly.

On both of my brandy runs with a thumper, I've had almost the entire run at 80-84abv, with evidence of tails coming in the high 60's-70's.
First run I charged the thumper with apples and water, second one, wine and fruit syrup.
I love the thumper for it's ability to boost flavours but the proof bump is not something I really want, as I don't want to age product at nearly 80abv or have to immediately add water to my product for aging.

So, what techniques do you guys regularly employ in order to keep the proof at a level that suits you on a spirit run?

"On both of my brandy runs with a thumper"
I think using a thumper was a mistake. It's not the traditional way of making brandy for a reason.
Thumpers will raise the ABV but compared to strip and spirit runs don't do as good job of cleaning up the character.

For the record Shady you're totally correct of course, I know it's not the traditional way for making brandy, I only used the thumper to try getting the most fruit flavours out of the spirit run, since I'm using fruit juice concentrate as the ferment base and not whole fruits.
I'm still following a full strip and spirit run protocol, just adding low wines to the boiler and flavouring items to the thumper.

[MooseMan]

MooseMan,

I put your run on the HD Pot and Thumper Calculator and got fairly close to your results. Then I played with various set points and found an easy way to lower your product abv.

First your current operation.
After the heads, I got about 81% abv product coming over from the thumper for about halfway into the run then slowly dropping down to 69% abv after 20 liters were made. So about 15 liters of hearts made at almost 80% abv.

A concern of the run was the fill of the thumper, it got up to 30 liters at the end. So watch out for this. Did you check the thumper fill at the end of the run?

Here is a printout of key variables during the run. The last partial column on the right is the Thumper Fill - 30L at the end. The column of Thumper ABV% is the product out the spout, next is the Cumulative ABV %. Also, you see that the vapor out the pot is greater than the vapor out the thumper, that is why the thumper fills.


image.png


What can be done to reduce the ABV% of the product?

I looked at several changes to the input data and did not see much change in the product ABV. Then I tried this:

Put 15 L of VERY HOT ( 75C ) water in the thumper to start with.

This will reduce the time it takes for the thumper to start boiling ( 12 min vs 33 min ). Which reduces the amount of 79% to 69% abv stuff coming over from the pot. So you end up with a lower thumper liquid abv when boiling starts and a lower product vapor abv.

Below next is that key variable ( thumper liquid abv ) during the run for your current run and next for the VERY HOT water run. You see that the VERY HOT water case, the Thumper Liquid ABV% is initially about 10% lower in the run then the difference reduces down to zero and at the end is a little higher. So the thumper vapor will also be lower for most of the run.


image.png

image.png


And last is a printout of all the key variables of the VERY HOT water run. The Thumper %ABV out the spout is about 5% to 4% lower the first half of the run. If you could start with 20L of VERY HOT water in the thumper. the thumper product would have even a lower abv. But you have to watch out for overfill of the thumper.


image.png


And maybe it is mainly the heads abv that is being reduced. The hearts abv might not be reduced as much. So, try this and see if it gets the lower abv that you want.

Haggy

Haggy thank you that is a metric ton of information!

I'll have to digest this a bit and get some of it down in notes I think, but my key takeaways are;
Use 0abv liquid additions to the thumper only
Pre-heat the thumper contents

I didn't measure the thumper contents, but I would guess there was approx 20lts in there at the end of the run.

I'll water down my next (Already stripped) brandy run low wines in the boiler too, as I think I'm starting too high.

[corene1]

Interesting subject here. It has been a few years since I have distilled any spirits, but when I was running a thumper I found that the easiest way to lower the ABV of the hearts and maximize flavor was to lower the ABV of the boiler charge. Often times I would strip the ferment hard and fast down to about 25% Abv saving some of the original ferment to add to the low wines when doing my spirit run . I liked to do my spirit runs starting at about 20% ABV in the boiler and add some of the less cleared ferment to the thumper as well as flavorings if you want. If memory serves I would have hearts coming out at about 70%.

[MooseMan]

Thanks Corene, that's much closer to what I'm aiming for as an aging proof so that puts me at ease a little.
I'm definitely going to charge the boiler at a lower proof next time, and put no alcohol at all in the thumper.

I held off using a thumper for a long time, so I knew I'd have to re learn when using one.

[Beerswimmer]

Maybe a better way to lower would be say 1/2 wash and half strip in the boiler starting out with a lower proof potential? Never ran a thumper run, but just going from what I’ve pulled from reading. Wouldn’t diluting the ABV of a strip with fresh wash both lower the output proof and increase the flavor potential?

A 1.5x distillation, same with Corene I think. You strip, add that to the boiler with the next batch of wash and do a final spirit run. Vs filling the boiler with only strip. Adds flavor and lowers the abv of the boiler charge. I do it for whiskey and rums and anything where I want the max flavor, like fruit brandy.

I thought most people did 1.5's

I use a thumper for stripping all the time, haven't really noticed a change in my low wines but I run as hard/fast as possible on strips. I do it for volume, not because it changes anything flavor or proof wise. Using a thumper for spirit runs is going to be too high proof for flavor, so I don't do it too often

[Tammuz]

I've ever played with apples. But I always have an unfounded opinion. I would strip low with the thumper,saving some wash for the spirit run. Then add some wash to the boiler to get it close to 20% . I would then add some dried apples to your vapor path. Maybe some more dried apples in your heart jar for a day or two. Apples here in Mexico cost more then rye,so close to silver prices.