Reversed Recirculating Mash Set Up

[Justin]

Good afternoon gentlemen.

It's been a slow day and I'm off to Sydney tomorrow morning so I'm, as usual, not doing much work (I will be dropping into the Belgian Beer Cafe, Redoak and probably the Lord nelson or others on the Rocks while I'm there too-can't wait but unfortunately I'm on a tight time scedule). Again as usual I'm planning the next move in brewing which is probably going to be a redesign, involving lowering everything down to a two tier and pump which most likely will end in a recirculating system. Anyway, that's irrelevant.

Now a question to the recirculators on this forum, do any of you/or have any of you considered the option of reversing the "typical" direction of recirculation? By typical I mean that of drawing the wort from under the grain bed, through the pump and exchanger back to the top of the grain bed. The reverse direction being drawing the wort off the top of the grain bed, circulating through the pump and exchanger and feeding back into the bottom of the tun.

From reading and experience it seems that mash compaction and subsequently a stuck mash can be a very real problem when drawing too quickly from the bottom of the mash and is particularly traumatic when using a pump to draw the wort from underneath the bed. So how many, if any, have considered pumping in the reverse diection to avoid this problem. Of course the direction is again returned to typical when sparging.

Basically I'm just opening up a discussion to see what the thoughts are on this idea. I have found only one person/homebrewery on the net that does his recirculation this way and I'm just keen to see if other have thought/tried it and what there take on it is.

Cheers, Justin

 

[big d]

hi justin
havent moved down a tier yet but the most obvious question that springs to mind is how do you get past the grain bed to remove all the wort.gravity dictates that the flow is naturally down.im curious as to how you can achieve this without manually holding a hose with filter attached and slowly lowering it into the mash.either way im sure you will encounter stuck run offs.
to avoid stuck runnings i would have a valve in the line to regulate flow.
as i said above i havent gone down this line yet but these thoughts spring to mind.
maybe wrong.
as you said i hope it leads to some more discussion.

cheers
big d

 

[Justin]

Ah, perhaps I haven't conveyed myself well enough.

What I mean is when your recirculating to maintain temperature (probably not a worry for you big d due to your cooler, but with a keg you do loose some temp) or to step up the temp, you recirculate your wort through a heat exchanger in your HLT or through a RIMS chamber.

In order to do this you pump wort out the bottom tap of your mash tun, go through the pump, though the heat exchanger and then return it onto the top of the grain bed. I have read numerous report of people compacting (or getting a stuck mash) their grain bed by pumping too fast, or using a high % of adjuncts-analagous to a stuck sparge. A lot of people put this down to the recirculation of the wort onto the grain bed and the sucking of wort from beneath it and gravity.

So therefore, if you were to reverse the flow of wort so that the wort is drawn off the top of the grain bed (just using a normal manifold, obviously below the wort level), then transfering the wort through the pump and heat exchanger, then returned to the bottom of the mash tun through your drain tap and manifold-you would therefore not be compressing the grain bed as the wort is flowing upwards through the grain bed to get back to your top intake manifold.

For the sparge you swap your hoses around and return to the conventional way of things by drawing from the bottom and returning to the top to clear the wort, then directing the wort over to the kettle.

I wish I could find the link of the blokes set up. I could follow his logic and it made sense to do it this way so I just wondered what other peoples thoughts were on doing things this way?

Cheers, Justin

 

[big d]

no worries justin
hope some of the ag recirc set up guys can help as im interested as well.

cheers
big d

 

[Darren]

Howdy Justin,
I have had occasinal thoughts about reverse recirculation and have always come to the conclusion of: What would be the advantage? You would always need to recirculate by conventional means to acheive a clear run-off so you would always be faced with the possibility of a "stuck sparge".
Now, reverse recirc could be useful to "unstick" a sparge. A blast of CO2 or compressed air would be equally effective in this case.
FWIW, I usually underlet my mash water under my grain bed (by gravity) and then recirculate bottom to top.
cheers
Darren

 

[dreamboat]

The possibility of a stuck sparge/compaction comes from those who use the pump plumbed directly into the manifold under the grain. This allows for the pump to create increased suction on the bed, more so if there is a slight stick, reducing the pathways for the liqour to flow through.
I use a grant when I recirculate, which allows the liquor to flow through the bed under gravity, just like it would when you sparge, then the pump draws from the grant, through the heater(coil in water), and back onto the top of the grain bed. This allows you to control the flow from the mash, and will let you see if there is some some sticking taking place.


dreamboat

 

[Darren]

The possibility of a stuck sparge/compaction comes from those who use the pump plumbed directly into the manifold under the grain. This allows for the pump to create increased suction on the bed, more so if there is a slight stick, reducing the pathways for the liqour to flow through.
I use a grant when I recirculate, which allows the liquor to flow through the bed under gravity, just like it would when you sparge, then the pump draws from the grant, through the heater(coil in water), and back onto the top of the grain bed. This allows you to control the flow from the mash, and will let you see if there is some some sticking taking place.


dreamboat

Howdy Dreamboat,
I have considered a grant because it would probably result in crystal clear run-off, especially if it too was fitted with some sore of manifold/screen.
I have been concerned about temp losses of the wort in the grant. Is this a problem DB?
FWIW, I have never had a stuck sparge even with pumping and a 50% unmalted wheat grist.
cheers
Darren

 

[Justin]

Damn, my reply that I wrote just disappeared? Take two.

Thanks for the reply guys. I agree with your comment on the fact that you end up reversing the cycle anyway Darren, when you come time to start the sparge and drain to your kettle, so you still end up with a stuck sparge possibility here, but as all grainers your faced with this one anyway which is rarely ever a problem. FWIW, I'd gravity feed this bit anyway. I just though that if your going to recirculate for a hour your going to be tempting fate.

Dreamboat, Darrens beaten me to the punch here and no disrespect intended but wouldn't you be getting a temp loss in your grant? This would end up being an up, down, up, down temp effect on your enzymes when you draw from the tun to the grant to the coil then to the tun again. As your enzymes are in solution, not just in the grain bed do you end up with this varied temp affecting your fermentabilities?

See, I'm thinking if you recirculated the other way you wouldn't need your grant because your not going to compact your bed. What do you other recirculators think about this idea? Thanks for the discussion guys, keeps my brain tickin .

Cheers, Justin

 

[The Brewing Farmer]

Interesting thought...no reason why it cant be done, just a matter of getting a pump that can force the wort thru the grain bed without blowing it all over the place and designing a manifold that will do it evenly

 

[Gulf Brewery]

You still need some way of setting the grain bed when you want to sparge and this has to come from the bottom of the lauter. Anyone got some unique ideas on how to reverse circulate and then sparge?

Cheers
Pedro

 

[Justin]

I was thinking that you could just stop the pump, let the mash settle for a minute, swap the hoses over (not sure if your going to loose wort here and make a big mess due to differences in height of wort in lines, or if this is a real possibility, depends if your quick disconnects stop flow when disconnected I guess). Then you start drawing from the bottom again, recirculating to the top and once the mash starts running clear you transfer the mash hose to your kettle, and shift the pump inlet hose to the HLT.

What sort of disconnects can you get? Do they have a check valve in them?

JD.

 

[jayse]

Hi Justin,
I think what you should proberly do here is maybe 'come back down to earth' for a couple minutes
No seriously, go with a conventional approach, i have never had a stuck sparge when pumping for 90 mins during the mash. So start from there and go from there iam sure you'll find its no major drama.
I used disconnects for awhile but didn't like them much so i swapped to having valves in which everything scews into.
I still have a bucket full of disconnects and really think they are not really a good way to set up your brewery.
I'll post a pick of the disconnects tommorow and if you reall want to go that way i'll give you a couple but my addvice would be don't go down that road.
All you need do is turn of a valve and the flow stops, it is much better that way i think.

Anyway my tid bit of addvice is get a pump and do it the normal way first and go from there.

Jayse

 

[Justin]

Yeah that's cool and I am one to follow conventional wisdom, I was just wondering what others thought about the idea but I hadn't actually considered doing it myself. It's a little way down the track doing this recirculation thing as myy current set up works wonderfully so initially I'm just going to get a pump and do my normal infusion mash with my current gear, just pumping my sparge water instead.

Disappointed to hear about the disconnects. I thought they may have been a nice option, so are you saying that you unscrew to change your hoses over or do you pretty much not move any hose and just flick a valve across.

Where are these pictures of your brewery Jayse, you've promised them for some time now. Do you really brew

Cheers, Justin.

P.S. This can be the end of the discussion

 

[jayse]

so are you saying that you unscrew to change your hoses over or do you pretty much not move any hose and just flick a valve across.

Where are these pictures of your brewery Jayse, you've promised them for some time now. Do you really brew

Cheers, Justin.

The valves are a bit of both some line swapping and some valve shutting off and opening the other one to send wort somewhere else ie from herms switched to the CFC.

The main thing i didn't like about the dissconnects where all the parts inside them, they are couplers and the ball bearings are not the best grade S/S either which resulted in them not lasting the distance.
But all in all they are allright but i just didn't like them much.
didn't get any batteries for the digicam today so pics will have to wait till later.

Here's a pic of the old brewery just to show i do brew


Jayse

 

[JasonY]

didn't get any batteries for the digicam today so pics will have to wait till later.

Was going to say where is that 90L boiler or whatever size it was!

 

[dreamboat]

I do not find any problems with the temperature changing through the grant process, ie no negative impact on the beer.
You will get heat loss from any system you use, and the more complex the system (more hoses valves etc) then the more heat you would expect to lose. Once the thermal mass of the grant is up to the same temperature as the liquor flowing into it (theoretically it will always be a touch lower) then the liquor will not be cooled greatly by this step.

dreamboat

 

[bigholty]

Wow, this is an old thread, but I've just completed a 'wet trial run' with a new brewing setup that will employ a reversed 'bottom to top' wort flow through the MLT. The brew length will be around 120 litres of finished beer, which is why I've tried it with just water first - I want some data before I commit a whole bag of grain to the brewing Gods! It has been many years in the conceiving and making - probably since around the time this thread started! It's probably been almost as long since I posted on this forum, but I thought this would be of general interest to the brewing community as I haven't found much reference on-line to this type of process for mash recirculation. I'll post some photos shortly, but in essence I plan to recirculate wort going IN to the bottom of the mash tan, and extract it OUT from the top via a kind of upside-down floating false bottom. The reason I've gone for this approach instead of heeding conventional wisdom as Jayse advocates, is that the vessels I got for this set-up many years ago have a fairly tall and narrow dimension (MLT is around 450mm diam. x 950mm height). My thoughts were that having a tall narrow grain bed would just be begging for countless stuck-sparges in a normal mash/lauter arrangement. I worked at a pharmaceutical company some time ago which employed fluidised bed equipment, whereby air was passed upwards through a screen into a bed of tiny starch spheres onto which the active ingredient was coated. Seems like a good idea, I reckon I can skip all the complicated fluid dynamics computation and just make beer the same way! Surely liquid wort and grain will behave the same way....

Stay tuned and we'll find out what happens.

If all else fails, I can always run it the conventional way and just invest in a rice-hull company and a mash paddle with a nice padded handle....

Bigholty.

 

[The Mack]

Sounds almost identical to how a Braumeister works?

 

[bigholty]

That's promising! I'm not that familiar with Braumeister-type brewing, I'm aware of them but have never seen one in action. Just when I thought I'd run out of things to watch on youtube…...