Ask The Brewmasters

We are in the process of having a new 7bbl steam brewhouse made.  We have to have a combo boil kettle whirlpool due to space issues.  For the wort draw off outlet our manufacturer normally just goes with a hop/trub dam and the draw off outlet located on the edge of the kettle.  I know a lot of brewers have issues with this sort of design.  Enough hops and trub can get sucked out to clog wort filters and the HX especially with heavy WP hopping.  I was wondering what better designs are out there.

Because the system will be hard piped I doubt there is any kind of racking arm that would work.  Would a second draw off outlet on the side be a good idea?  I could pull clean wort through that until the level got too low then switch to the the outlet on the bottom of the kettle.  Would a stand pipe do the same job?  

Or, am I just over thinking this whole thing?

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Patrick Brown
Brewer
2nd Story Ale Works
Tokushima, Japan
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Hi Patrick

Funny enough (sort of) I am brewing on a 10 bbl system that has this same same set up and the same issues, I have been thinking about this and was going thinking about getting a large stainless mesh circle matching the diameter of the existing dam, made and attached to the bottom with the idea that the Trub gets trapped in the center and the wort filters out.

I was planning to bolt it to the existing Dam, just in case it does not work or there is some other issue that develops, then once we know it works (if) then weld it to the kettle bottom.

I know this won't stop all the Trub, but I think it would reduce the amount of large blobs that we also get breaking away and heading to the heat exchanger. 

I hope this explanation makes some sense. 

David - Drop Bear Brewery Eugene Oregon.

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David Lehane
CEO
Drop Bear Brewery
Eugene OR
(269) 267-7722
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Hi Patrick,

I see plenty of breweries able to get good knockout with a similar configuration. One thing to keep in mind is that there are liquid hops available for the whirlpool that can lessen or eliminate the trub from hops in the whirlpool. You still have to deal with the protein break. Some breweries I talk to have the knockout port too high on the side of the whirlpool, thus eliminating the possibility of getting the last of the wort knocked out . Hope this helps.

Paul Allard

Willamette Valley Hops

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Cheers,
Paul Michael Allard
• East Coast Territory Manager
• Hop Product Technical Specialist
Willamette Valley Hops, LLC
m 207.807.7074 (Maine)
e paul.allard@wvhops.com
o 503.633.4677 (Oregon office)
f 503.633.4679
w willamettevalleyhops.com
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A second outlet can never hurt.  As you consider it what volume of wort will be left in the bottom of the kettle based upon the dish geometry?  If you can't improve that significantly or have it in a location that by calculation makes sense for theoretical trub levels it may not be worth the extra cost.   I believe given large hop loads, the second draw off provides additional settling time without creating flow patterns by the edge of the trub pile which will destabilize it while most should be held back by the dam.  If you are using fining agents in the kettle personally I believe the damn is sufficient.  Dumping a bit of trub at 12 - 18 hours will generally confirm the carryover providing you aren't plugging you chiller.

From a supplier perspective,  it will add another penetration to you steam jacket that with good welding practices shouldn't be an issue. 

Other things to consider, especially with steam kettles, consider turning off your bottom jacket towards the end of the boil.   Condensate left in the jacket and time for it to equilize with the wort is beneficial to help set the trub pile.  I've observed several operations where you can see rolling liquid caused by poor condensate removal or leaking steam valves.

Cheers,

Tim

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Timothy Hawn

Director of Operations
Craft Kettle Brewing Equipment
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Hello Patrick,

It is an interesting question and you see there are many good ideals and designs. I think before getting into a design, need to think about the scope/propose. It may not be possible to have a design works well for normal strength of lager and double IPA due to the amount of trub and hops.

A whirlpool tank with trub dam/sloped bottom/side trench, its bottom surface area can be calculated based on the type of beer mostly brewed. The more information you provide, your fabricator could make an assumption more close to hold the majority of the trub. A racking arm or stand pipe is based on the relatively similar concept which is difficulty to clean, in my opinion.

Thus, it will be either having more losses or more trub comes down the knock out where a strainer/filter/hop back can be placed to catch before trapped in the PHE.

If I would choose for your 7 bbl combi-tank, if it is with steam jackets, I simply go with the design in pic you have shown. The dam is not that necessary since if the amount of trub is greater, it will be sucked in the pump from the two ends or above the dam no matter what. Therefore, I recommend to remove it.

Cheers,

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James Tien
Whitby ON
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