Help me break my OCD analysis paralysis RE: thumper sizing

[Stags]

Hey folks. Hoping yall can help me break my personal analysis paralysis. Fundamental question- to add a 15 gallon or a 10 gallon thumper? Sitch is below:

I currently have a 10 gallon pot, 5 gallon thump, and 3 gallon worm. All powered by 2x 2kw elements. All copper. She worked really nice for UJSSM and sugar washes.

Recently got a new job and more $ so I figured I’d splurge on some new materials and equipment. I’ve also gotten proficient at all grain mashes but I absolutely hate filtering and wringing the grains.

My thoughts have centered around building a new 15 gallon primary and either a 15 or 10 gallon thumper to feed into my existing 5 gallon thumper and 3 gallon worm. So 15/15/5/3 or 15/10/5/3

My intention would be to strip with water in the primary and unfiltered mash in the big thump. Spirit runs through grain in the big thump as well, primary charged with low wines. Added benefit is that the primary and elements would only ever see clear low wines and water, so less cleaning burden/ longer life for that equipment. I’ve done enough math to conclude that I can achieve my objective of bold full flavored and bodied whiskey in either setup depending on how I charge and run her.

Thoughts on 15:
+More mash per run/ fewer strips
+Lower abv on spirit run from more 5% mash in system
-longer run times/ less control
-higher likelihood of dry elements

Thoughts on 10:
- more stripping runs required
+ more refined product from lower grain charge in spirit run
+better controllability due to smaller size relative to power input/ shorter run time
+lower risk of dry elements

On a purely objective basis, I think the 15 gallon thump has a slight edge just due to volume. That said my brain loves the idea of 15/10/5/3 because my brain loves the pattern in the numbers. 15/15/5/3 turns my math brain off. So I put it to the masters: 15 or 10?

[Rusty Ole Bucket]

I'm about to add a 15.5 keg to my 15.5/7.75 set up as part of an upgrade/rebuild, in fact the Twisted Brick shotgun build part of it is kicking off this weekend I hope. I'm planning to go to steam for grain and do a lot more rum in the future with the addition of the extra thumper.

I think you might eventually miss that extra volume, if you decide to do a steam run you're limited by the smaller pot and charge size.

I'm green as grass at this so I might be way off base in my reasoning, but it makes sense to me.

Rusty

[Tammuz]

I'd go with the 15 as a thumper/boiler. My retort/thumpers can be run as a steam gen. ,boiler and thumper. I plan on using all 3 to strip rum at the same time if I get the power in.
You might need to upgrade your elements if you want a faster heat up.

[NZChris]

15. You can run with clear wash in the pot, grain in the first retort and something of your choice in the final retort. No need for stripping runs as each run produces finished spirit. Look up how the Jamaicans use them for rum for some ideas on how to charge them.

[Dr Griz]

I'm with the rest of these fellas. A thumper as big as your boiler gives a lot more flexibility.

I've been stripping my wash with steam the last few runs (I got tired of walking the razor's edge with rye mashes), and I've found that overfilling the thumper is a bigger problem than running your element dry. After all, if you're charging your boiler with water, you can fill it just about to the top without risk of boiling over. But that steam will condense out into your thumper charge as it comes up to speed.

Hell, I just flipped my 15-8 rig around on my last run just for giggles, using my 15 gallon keg as a thumper, powered by an 8 gallon boiler.
I ran 9 gallons of wash in the thumper, and much to my surprise, it worked a treat! If I can replicate that, I reckon I've just cut my stripping runs from 3 to 2!

[zach]

I suggest a thumper bigger than the boiler. I use a 23 gallon milk can for a thumper and a 15 gallon keg for steam.

If you use a keg for a thumper, I would install at least a 6 inch tri clamp for a clean out.

[OtisT]

I'm with the rest of these fellas. A thumper as big as your boiler gives a lot more flexibility.

+1

[shadylane]

A thumper 1/3 - 1/2 the boiler size if making only rum.
Too big and the thumper will want to over fill due to passive reflux from the heat it radiates.

For a steam rig, a thumper the same size or even bigger than the pot.
Most important is designing the thumper for ease of draining, filling and cleaning.