Whirlpool

[wes1977]

For those that are using a pump for their whirlpool. What flow rate do you have? I have 19L/min but think I need something a little more manly!

 

[Dan Pratt]

If your doing a single batch the kettle volume for whirpool would be approx 25L so in 1 minute you would have recirculated 80% of the wort. Even for a double batch that is plenty IMO, usually whirlpool from 10 to 20mins.

Why would 19L/min not be enough?

 

[wes1977]

I Whirlpool for about 30mins with little impact!! Perhaps it's my technique?

 

[MHB]

It isn't so much a question of L/m as m/s the velocity of the liquor, the shape and direction of the return to the kettle, the amount of crap like pipes and fittings in the kettle that impede whirlpooling and the shape of the kettle itself.
So just to cover the basics of whirlpool design: -
The pot should have smooth surfaces with no protruding plumbing that will cause eddy currents which will interfere with the whirlpooling action
The best shape (for small/home brewers) is a flat bottom vertical sided "pot" where when full the wort is between 1:1 and 1:2 diameters high
Wort entry is best at not more than 1/3 of the fill height and at 10o in from the tangential
The velocity of the wort return should not exceed 3m/s, any faster and you start to mush up the flock that you formed during boiling, this makes settling slower and gives less effective wort/trub separation - negating the why we whirlpool in the first place.

Given you are pumping at 19L/minute, your wort return velocity (lets do it all in seconds)
19L/m is 0.317L/s
If your return was say a piece of 1/2" copper pipe (pretty common among home brewers) the inside diameter (ID) would be (well the Bunning's annealed copper is 10.88mm ID) the Area (Pir2) and we want all the units to be metres and seconds
Volume is 3.1666x10-4 m3/s
Diameter is 0.0188m
From Velocity = (4*flow rate)/(Pi*diameter2)
Velocity = (4*3.1666x10-4)/(Pi*0.010882) = 0.0012666666664/0.0001183744 = 3.4m/s

So I'm going to say you don't need a bigger pump, in fact it might be causing problems and you really need to look at some of the other features of whirlpool design.
Maybe even wind the pump back a bit or use a slightly lager return
Mark

 

[wes1977]

Have you got any photos of your setup you don't mind sharing?

 

[MHB]

I mostly brew on a small (nano) commercial system, it isn't here so not today, point being it would be the most boring pick of all time, "stainless pot with two holes" One in the bottom near the edge, one in the side about 75mm up from the bottom (tangential) - importantly nothing else.
Mostly do 120L batches, kettle loss is around 2-5L depending on the beer and how much I need another couple of litres...

Just went had a troll through Google images, really couldn't find anything that was the same the closest was this one in a home brew talk thread.

Without the copper pipe, its a good whirlpool. I am startled at how many really bad whirlpool designs there were out there. I suppose its no surprise that people spend so much time and money on false bottoms, hop spiders and the like when you see how crappy most of the designs are.

There should be nothing in the kettle/whirlpool but wort, no pickup tubes, pipe return lines, elements, thermo wells...
Make it super simple let it finish moving and draw down slowly.
Mark

 

[wes1977]

Thanks for your detail replies, greatly appreciated. For my whirlpool I suck up from the bottom using the main drain tap. Do you recommend having a separate one sucking in the correct direction?

 

[wes1977]

My cone looks nothing like that...... That one looks set, mine is all loose and across the who kettle! Should I use more whirlfloc?

 

[MHB]

Not really, I doubt there is a "Right" direction, mine is near the edge pointing down through the floor of the kettle, the return is at the side and looks like a big ellipse.
Plenty of Whirlpool/kettles have the pickup on the side (streak) , usually close to the bottom. Quite a few larger commercial whirlpools have a couple of pickups down the side, as the wort clears from the top, you can draw off from higher up if it's important to speed up throughput..

Some of the more modern dedicated whirlpool are getting a lot wider than they are tall, numbers above were fro a whirlpool kettle (which is what most of us have) typical modern whirlpools are quite shallow 1:0.8 being average, but as low as 1:0.25 (H)

Mark

Edit
Whirlfloc wont make the trub cone, it really helps to settle it faster and tighter, if you have a messy trub cone look to your design.
M

 

[wes1977]

 

[wes1977]

The above pic is my homemade effort realising the science involved. As you can see the in and out are quite close to each other.

 

[billygoat]

The above pic is my homemade effort realising the science involved. As you can see the in and out are quite close to each other.

Are you whirlpooling while the wort is hot or are you whirlpooling after chilling in the kettle, ie- using an immersion chiller?

 

[Fat Bastard]

I've had some experience with power whirlpooling on a homebrew scale.

Initially i stared using the ubiquitous Little Brown Pump, and a gooseneck type device that would allow me to vary the height and angle of the wort return to get the best cone. I found the best height was approximately 1/3 of the way to the bottom, 30 degrees to the tangent and angles slightly upwards.

I've since made it a permanent arrangement with a bigger pump (Ultimiser) and dedicated inlet & return fittings in the pot. It gets a cone happening with a 10min whirlpool and 10 min stand, despite having all sorts of turbulence causing fittings and a dirty great element in the kettle. I think the best aid to whirlpooling is probably a decent sized vessel, under 50l just seems to be too small for the velocity at the edge of the vessel to get to the point where it creates a compact cone.

Don't get me wrong, mine works, and works well enough to so the job, but a properly dimensioned vessel wild make it far easier!

There is some pics of it floating around the forums if you care to search. If I can find a pic, I'll post it later.

 

[wes1977]

I whirlpool hot, is that my mistake?

 

[wes1977]

Should it look like this during the whirlpool?

 

[wes1977]

No sorry, I whirlpool cold.

I remove the chiller and leave it whirlpooling for about 30 mins.

 

[billygoat]

These photos show the effects of whirlpooling while the wort is hot, and whirlpooling after the wort has been chilled in the kettle.
Even though there are 2 elements, a pick up tube and a return arm, when I whirlpool while the wort is hot I get a good cone formation.
I use a March 809 and usually have that going for about 15 mins and then let settle for about 20 mins.

 

[MHB]

There are two types of break material, Hot break coagulates and settles relatively quickly and easily. Cold break on the other had is very light and fluffy, settles very slowly and wont form a nice compact trub cone even if you wait for a ridiculously long time.
Fortunately Cold break isn't an issue for us, it is only a matter of concern if your malt and/or adjunct provides a very large protein load, if you are using good brewing ingredients and doing the basic processes properly you can forget about cold break.

Personally I go the some lengths to keep hot break out of my fermenters. Whirlpool, counter flow chill on the way to the fermenter, pitch yeast...
If you are using an immersion chiller it becomes a lot harder to tell where cold break ends and hot break starts. If you do a brew or two on your system and run the hot wort of to a no chill cube you should get a pretty good feel for how much you need to leave in the kettle to make sure you aren't drawing in the hot break, then just go with that and forget about the cold break. Wort is pretty cheap, even if you budget an extra litre of loss just to be sure, you will end up with better beer.

One other factor that can make a big difference to your break formation and the way it settles is Calcium, giving your location as Australia makes it hard to give any advice on your water, but it might be worth adding some extra (say 50-100ppm) of Ca late in the boil, use a good kettle fining (I like BrewBright) but there are plenty of other products out there. Remember that with all kettle finings More Isn't Better! there is a right dose that will give the best result.

Good luck and hope you get good beers
Mark

 

[DJ_L3ThAL]

The velocity of the wort return should not exceed 3m/s, any faster and you start to mush up the flock that you formed during boiling, this makes settling slower and gives less effective wort/trub separation - negating the why we whirlpool in the first place.


[]

Mark that's really interesting, Once the wort is down to about 90C I use a stainless round bar with a 100mm long tee piece welded to the end, put that into my electric drill and just run it as fast as I can for a minute as fast as I can without splashing /sucking air into the centre of the whirlpool and let that settle for another 10-15mins. It appears to settle out as a reasonably tight cone and I get pretty clear wort (using Whirlfloc).

But am I potentially stirring in hot break particles which won't settle out and are less visible? Or is this hot break formed during the boil quite visible if it remains stirred into the wort?

 

[MHB]

Hot break once has formed (and any that is going to form has by the time the wort has cooled to 90oC) it's a bit like snowflakes, they will settle. What determines the rate that they settle is described by Stokes Law, if you have a play with the variables turn out that the bigger the flock particles are the faster they settle.
By creating high sheer forces (turbulence...) inside some types of pumps or by frappeing the crap out of the wort, you will break the flock into smaller bits that will take longer to settle.
You would be better off replacing the 10mm crossbar with something like a piece of 50x150-200 flat sheet and not spinning the drill too fast, just a little faster than the liquor is rotating, ideally slowly increase the speed of the stirrer as the rotation of the wort picks up, or use a really big spoon.
Mark

Stokes Law, good read

 

[verysupple]

No sorry, I whirlpool cold.

I remove the chiller and leave it whirlpooling for about 30 mins.

Mark already alluded to it above and billygoat provided some good pics illustrating it, but I think whirlpooling cold might be the biggest problem you have. I stir by hand with a spoon instead of pumping, but I could never get a nice cone in my old pot (19 L BigW one) even with no fittings etc disturbing the flow. I recently got a much bigger pot (60 L, 44 cm diameter) and still the trub cone was pretty rubbish - so it might not have only been the pot size casuing the problem. There would kind of be a cone but it would spread out over the whole bottom as I drained, and I drained very slowly.

The last two batches I've no-chilled and the trub cones have been a lot better - fairly stable; the edges just started to break up while draining the last little bit of wort. Solution: make more wort next time so I can leave the extra ~500 mL behind. I think the cold break generally makes what cone does form unstable, so by the time you've drained enough wort that you can see it, it's all spread out and not cone-like any more.

So if you don't want to change your system to be able to whirlpool hot, I think the easiest solution is to make a bit more wort so you can leave more behind and not suck up as much hot break. At least that's what I did.

 

[verysupple]

Hot break once has formed (and any that is going to form has by the time the wort has cooled to 90oC) it's a bit like snowflakes, they will settle. What determines the rate that they settle is described by Stokes Law, if you have a play with the variables turn out that the bigger the flock particles are the faster they settle.
By creating high sheer forces (turbulence...) inside some types of pumps or by frappeing the crap out of the wort, you will break the flock into smaller bits that will take longer to settle.
You would be better off replacing the 10mm crossbar with something like a piece of 50x150-200 flat sheet and not spinning the drill too fast, just a little faster than the liquor is rotating, ideally slowly increase the speed of the stirrer as the rotation of the wort picks up, or use a really big spoon.
Mark

Stokes Law, good read

stokes-equation.jpg

Nice post. Note that viscosity is in the denominator, so the sedimentation rate will be higher for hot wort than for cold. I'm not sure that's much of a problem though (or even a very large effect), you'd just have to let it settle a bit longer.

 

[DJ_L3ThAL]

Hot break once has formed (and any that is going to form has by the time the wort has cooled to 90oC) it's a bit like snowflakes, they will settle. What determines the rate that they settle is described by Stokes Law, if you have a play with the variables turn out that the bigger the flock particles are the faster they settle.
By creating high sheer forces (turbulence...) inside some types of pumps or by frappeing the crap out of the wort, you will break the flock into smaller bits that will take longer to settle.
You would be better off replacing the 10mm crossbar with something like a piece of 50x150-200 flat sheet and not spinning the drill too fast, just a little faster than the liquor is rotating, ideally slowly increase the speed of the stirrer as the rotation of the wort picks up, or use a really big spoon.
Mark

Stokes Law, good read

stokes-equation.jpg

Thanks for that, really good info! Remember stokes law from uni, eek!

Thinking how small the Kaixin and similar pump heads and impellers are, wouldn't running through a pump to whirlpool be chopping up the break material similar to the round bar I've been using?

 

[MHB]

Thanks for that, really good info! Remember stokes law from uni, eek!

Thinking how small the Kaixin and similar pump heads and impellers are, wouldn't running through a pump to whirlpool be chopping up the break material similar to the round bar I've been using?

Well there you go opening a whole can of worms, and just before lunch to.

Short answer is- Maybe. Pumps are designed to manage the liquid going through them in different ways, some pumps create very small sheer forces in the liquid, I have seen a demo of a pump used to pump live fish, but the smallest of those would cost a bit more then a new BMW.

A well made pump designed to handle hot liquids should be fine, some of the cheap products out there are exactly that cheap, lacking any other virtues. Problem is that we all have to make compromises, but if the pump isn't cavitating then its probably doing a pretty decent job, run it for as little time as you can to establish the whirlpool (should be only a couple of minutes) shut it down and let Stokes do his thing.
Mark

VS
Nothing like getting your head around an equation to help with defining reality.
I tend to run the pump while the boil is still in progress, sterilising the lines and CFC, shut down the pump, add BrewBright (as a slurry) and any flame out hops, put the lid on and go for a cuppa an a smoke.
As noted fastest settling when hottest, adding the BrewBright as a slurry, it looks like someone has dumped in a packet of croutons, huge flock particles form nearly instantly then drop like a rock, and the late hops wiz around with the wort for a bit and go to the bottom with the rest of the trub where I want it. Now if we can just find a way dial up the g a bit...
M

 

[user 36151]

I whirlpool hot, is that my mistake?

i now whirlpool hot since i got a plate hx i have found to get perfect trub cone i need to eliminate all convection currents i insulate the kettle and leave lid on for the whole process until wort stops flowing out of the kettle. an accidental experiment i did i forgot to push the pick up to the floor of the kettle so lifted the lid to push it down as i lifted the lid and the steam escaped the perfect 5cm high cone fell apart before my eyes and mixed in with the 5cm of clear wort that was left all because steam was allowed to escape and convection created.i add brewbrite slury whirlpool by hand with a spoon then cover, insulate leave for 30 mins then run out into hx only opening the kettle once all wort collected.this is what works for for me.i tried pumps and drill things ect.

 

[glenwal]

Now if we can just find a way dial up the g a bit...
M

Hmm, whirlpooling in a kettle in a centrifuge. I'm sure someone around here is crazy enough to try it.

 

[MHB]

Crazy as, I do have a little Alpha Laval continuous centrifuge, and yes I have tried it (years ago) and no it isn't worth it.
You can get very bright wort but you have to factor in the cost of a centrifuge, the extra time it takes to process the wort and the really small amount of extra wort you get, it just isn't worth it.
I have heard of some big (I mean really big) breweries sending kettle bottoms and lots of other waste (tank bottoms after lagering, waste from grain pressing and the like) to be processed in part by centrifugation but that had a lot more to do with waste water discharge than wort recovery. The solids can mostly be sold as animal feed, rather than being sent to waste at an ever growing cost.

Brewing and malting as industries are fairly profligate users of both energy and water, and produce quite a lot of BOD type waste, it is something to be aware of. Good design can save a brewery quite a lot in ongoing operational cost. If you pay any attention to what's happening in the world, I think we can all guess that the cost of energy, clean water and waste disposal aren't going to go down any time soon.

 

[Alex.Tas]

Awesome information in this thread. Thanks to everyone involved.

One question to throw out there: do people think that adding pellet hops in loose help or hinder trub cone formation, or alternatively makes no difference.
I use a hop bag, but would be interested to know if throwing them in loose may help form a tight trub cone. obviously there would be more crud in the bottom of the kettle though because the hops aren't removed via the hop bag.
The reason i ask is that some of the best photos of i have seen are of trub cones that are greenish in colour.

 

[Tilt]

Fortunately Cold break isn't an issue for us, it is only a matter of concern if your malt and/or adjunct provides a very large protein load, if you are using good brewing ingredients and doing the basic processes properly you can forget about cold break.

Personally I go the some lengths to keep hot break out of my fermenters. Whirlpool, counter flow chill on the way to the fermenter, pitch yeast...
If you are using an immersion chiller it becomes a lot harder to tell where cold break ends and hot break starts. If you do a brew or two on your system and run the hot wort of to a no chill cube you should get a pretty good feel for how much you need to leave in the kettle to make sure you aren't drawing in the hot break, then just go with that and forget about the cold break.

MHB - this is something I haven't fully appreciated before.
I was under the impression that all break material has a negative impact on finished beer storage / flavour stability, clarity etc. as well as making it more difficult to rinse and re-use yeast.
For that reason I'd thought that in-line chillers (CFC and plate chillers used on the way to the fermentor) lead to all of the cold break ending up in the ferment and subsequent reduction in beer quality.

To date I've stuck to creating extra wort, whirlpooling by hand and immersion chilling and running the clear wort off to the fermentor (then recovering usable 'yeast starter wort' by leaving the trub etc to settle out in a jug in the fridge and decanting and freezing it for use later on). My aim was to leave behind all trub / break in the kettle.

I'm just upgrading to a new kettle and and revamping other parts of my system so am considering other options, particularly pump driven whirlpool and CFC.

Can you expand on the statement in red above .... i.e. when are the times that we should avoid cold break, and when is it OK to include it, plus whats the critical point that it becomes an issue for beer quality?

 

[MHB]

Awesome information in this thread. Thanks to everyone involved.

One question to throw out there: do people think that adding pellet hops in loose help or hinder trub cone formation, or alternatively makes no difference.
I use a hop bag, but would be interested to know if throwing them in loose may help form a tight trub cone. obviously there would be more crud in the bottom of the kettle though because the hops aren't removed via the hop bag.
The reason i ask is that some of the best photos of i have seen are of trub cones that are greenish in colour.

If you are whirlpooling effectively it wont matter if the hops are loose or not, well not to the trub but you will get better utilisation out of the hops if they are free to move around in the wort, I have seen as much as 20% better sighted but in my experience it is probably more in the 10-15% range. Mind you its a reasonable saving on bittering hops.
Not based on research but my impression is that a cone with hops in sticks together better a bit like reinforcing.

MHB - this is something I haven't fully appreciated before.
I was under the impression that all break material has a negative impact on finished beer storage / flavour stability, clarity etc. as well as making it more difficult to rinse and re-use yeast.
For that reason I'd thought that in-line chillers (CFC and plate chillers used on the way to the fermentor) lead to all of the cold break ending up in the ferment and subsequent reduction in beer quality.

Snip

Can you expand on the statement in red above .... i.e. when are the times that we should avoid cold break, and when is it OK to include it, plus whats the critical point that it becomes an issue for beer quality?

Wort needs to have a certain amount of protein in for a couple of reasons, one is that protein is a vital part of the pallet fullness of beer, too little and the beer tastes gutless, another is head retention, too little of the right molecular weight protein and the beer wont hold a head, a third is that its a vital yeast nutrient, too little and the yeast will struggle to reach the right population.
The important part about yeast reproducing in the wort is that it consumes some of the protein, ideally all of the lipids, sterols and fatty acids that it needs and that we don't want in the beer as well as all the Oxygen. If all these factors come together we get a clean wort with all the potentially stability reducing components removed, we also get a lot of healthy happy yeast that rill rip through the sugars in short order.

Proteins and there are potentially millions of different proteins in a wort, are very much a two edged sword we want enough of some and none of others, we group proteins by size and it turns out that the ones we want the least are the bigger ones that condense first and wind up in hot break soonest. The ones we want most are either still in solution or do form cold break but the yeast will quite haply pull that apart and eat it.
There is too much cold break when it starts to coat the yeast inhibiting its life cycle or it flocks in the fermenter stripping out iso-alpha acids. To get that much is nearly impossible unless you are using very low grade malt (American 6-row which needs low protein diluents) or lots of low grade adjunct. In effect if you are using decent quality brewing ingredients you can forget all about cold break.
If you think you are having problems with too much residual break, boil a bit longer, more of the higher MW proteins will condense earlier but all the proteins will be reduced by longer boil times, in lab testing after 6 hours hot break is still forming, just less of it and made up of smaller protein.
If your wort sample is bright and clear and the flock in it settles quickly to the bottom you would be on the right track, any turbidity that wont settle - keep boiling!

if you want to reuse the yeast, I would make a good clean wort, pitch a decent starter of healthy yeast and rack 24-48 hours after the start of ferment.
Any unused break material, hop fragments and dead yeast will be left behind, crop the yeast at the end of fermentation 4-5 days, keep all of the yeast cake it as it will be pretty dam pure yeast.
Mark