Slow sparging for recirculating mash

[morebierplease]

Hi Guys,

I'm a long time lurker here on AHB, this is my first post so go easy!

I've always been told that the slower the sparge the better. John Palmer says here:

The wort should be drained slowly to obtain the best extraction

http://howtobrew.com/book/section-3/getting-the-wort-out-lautering/aspects-of-lautering

I have myself a HERMS electric brewery and to maintain the mash temp and ascend temp to mash out, I find I need to recirculate the mash quite quickly. Perhaps 60% - 70% the capacity of the chugger pump. Perhaps 2 - 3L of wort per minute in a standard 15 - 16L mash. I measure my mash temp at the point where it comes out of the mash tun.

My question is, if I recirculate continuously at 2 - 3L of wort per minute, what would be the need to slow down that rate of flow when sparging?. I can visualise, for a static mash, that slow flow would be best, but I can't see how it would matter for a recirculating mash as you are constantly rinsing the grains.

 

[wide eyed and legless]

A really helpful book about lautering and sparging is Dave Miller's Home Brewing Guide he goes into great detail with explanations of the reasons why, highly recommend getting it

 

[Adr_0]

I ramp up to about 10-12lpm during temperature ramps, then roll back to 2-3lpm once it's at temperature. That's for sacch and mash out/sparge. Seems to work.

 

[RobB]

Palmer's advice is good, but I think it was written before recirculating systems became as common as they are now. In a more traditional 3V home brewing set up, slow sparging is good for two reasons. Firstly, it helps to avoid compacting the grain bed and ending up with a stuck sparge. Secondly, it gives your sparge water more contact time with the grains. At the end of the mash the wort absorbed within the grain will have the same gravity as the free wort which you have just drained. A slow sparge will allow more of this sugar to migrate from the grain to your low gravity sparge water. A really quick sparge is probably just a rinse, rather than a true sparge.

Because your system is recirculating, you already have a long contact time and your grain bed is obviously flowing well, so I'm not sure Palmer's advice really applies to you. I built myself a system which is similar to a grainfather and with a coarse crush and a fist full of rice hulls, I run the pump flat out at about twelve litres per minute. My extraction efficiency is about 85%, which is good enough for me.

I would recommend that you set your pump speed to whatever you need for maintaining even temperatures, avoiding scorching, etc. I don't think tweaking your pump speed will have a significant effect on your extraction.

 

[RobB]

...........and welcome to the forum!

 

[morebierplease]

Thanks guys, yeah its an issue that seems to be without a variety of discussion

My LHBS owner once tried a sample of brew that I made, he said that it had a bit of a chemical taste (I couldn't taste it, but I've got horrible taste identification skills). He said that can be caused by pulling the wort through the grain rather than letting it flow. So I've always been a bit blank as to which side of the fence to be on.

 

[Ducatiboy stu]

Always let the grain bed drain, dont try and pull it thru

the term is actually Vorlauf

http://brewbeeranddrinkit.com/vorlauf-lauter-and-sparge-in-english-please/


Vorlauf Lauter And Sparge In English Please

 

[Matplat]

As recirc brewers we still sparge though right? And we don't recirculate while sparging... (or is that something I've been doing wrong) so surely the duration of sparge does still apply?

Previously I've been lifting the malt pipe out fully as soon as the mash is complete, then sparging and letting the runnings fall into the kettle.

Next brew I'm planning to do the sparge before lifting the malt pipe in an attempt to slow the flow through the grainbed....

If you recirc while sparging, it seems like you may as well just do full volume - no sparge mash...?

 

[Crusty]

Palmer's advice is good, but I think it was written before recirculating systems became as common as they are now. In a more traditional 3V home brewing set up, slow sparging is good for two reasons. Firstly, it helps to avoid compacting the grain bed and ending up with a stuck sparge. Secondly, it gives your sparge water more contact time with the grains. At the end of the mash the wort absorbed within the grain will have the same gravity as the free wort which you have just drained. A slow sparge will allow more of this sugar to migrate from the grain to your low gravity sparge water. A really quick sparge is probably just a rinse, rather than a true sparge.

Because your system is recirculating, you already have a long contact time and your grain bed is obviously flowing well, so I'm not sure Palmer's advice really applies to you. I built myself a system which is similar to a grainfather and with a coarse crush and a fist full of rice hulls, I run the pump flat out at about twelve litres per minute. My extraction efficiency is about 85%, which is good enough for me.

I would recommend that you set your pump speed to whatever you need for maintaining even temperatures, avoiding scorching, etc. I don't think tweaking your pump speed will have a significant effect on your extraction.

Good advice there!
You'll achieve far better extraction rates from fly sparging compared to batch sparging.
I've always pretty much batch sparged but my new setup will allow me to fly sparge. Matching the pump flow to the kettle with the water pump flow for the sparge is the tricky bit. I'm looking at close to an hour for my sparge & this will add a bit of time to my brew day but the efficiency from it will be far greater than what I'm achieving now. Hopefully operational towards the end of this year.

 

[Ducatiboy stu]

Good advice there!
You'll achieve far better extraction rates from fly sparging compared to batch sparging.
I've always pretty much batch sparged but my new setup will allow me to fly sparge. Matching the pump flow to the kettle with the water pump flow for the sparge is the tricky bit. I'm looking at close to an hour for my sparge & this will add a bit of time to my brew day but the efficiency from it will be far greater than what I'm achieving now. Hopefully operational towards the end of this year.

Not always true. ( I would regularly hit %80 batch sparging )

There are tricks to both

Fly sparging can lead to problems.

Both work very well and you should get them same extraction from both, BUT you have to treat each method differently

 

[Crusty]

As recirc brewers we still sparge though right? And we don't recirculate while sparging... (or is that something I've been doing wrong) so surely the duration of sparge does still apply?

Previously I've been lifting the malt pipe out fully as soon as the mash is complete, then sparging and letting the runnings fall into the kettle.

Next brew I'm planning to do the sparge before lifting the malt pipe in an attempt to slow the flow through the grainbed....

If you recirc while sparging, it seems like you may as well just do full volume - no sparge mash...?

Fly sparging is simply adjusting your drain off rate to your sparge addition rate. Keeping a few cm of water over the grain bed whilst draining is what your aiming for. Doing a 1hr sparge as an example allows a lot of time for the grain bed to be in contact with the incoming water for the sparge. If people are getting 84%+ mash efficiency batch sparging, done correctly, you will get well up into the high 80's doing a fly sparge. Batch sparging just doesn't allow enough time for all that sugar to get rinsed out & little problems like channeling can occur in the grain bed that you just don't see. I know brewers that hit 90% mash efficiency fly sparging for 60-75mins.

 

[Ducatiboy stu]

Fly sparging can also have acidity issues

Fly sparging is simply adjusting your drain off rate to your sparge addition rate. Keeping a few cm of water over the grain bed whilst draining is what your aiming for. Doing a 1hr sparge as an example allows a lot of time for the grain bed to be in contact with the incoming water for the sparge. If people are getting 84%+ mash efficiency batch sparging, done correctly, you will get well up into the high 80's doing a fly sparge. Batch sparging just doesn't allow enough time for all that sugar to get rinsed out & little problems like channeling can occur in the grain bed that you just don't see. I know brewers that hit 90% mash efficiency fly sparging for 60-75mins.

Bullshit

 

[Matplat]

Because your system is recirculating, you already have a long contact time and your grain bed is obviously flowing well, so I'm not sure Palmer's advice really applies to you.

So this is the bit that was confusing me. Sparging and recirculating while mashing are two separate processes, so surely the same rules apply.

Those of you who achieve 80-85% efficiency, how do you slow down your sparge on a 1v system?

 

[Crusty]

Fly sparging can also have acidity issues





Bullshit[/quote

No bullshit.
Acidity issues or astringency can occur from either sparge but youd have to have your total grain bed temp well up into the high 80's for it to happen. A common problem of years gone by with flysparging was the length of time & volume applied to the grain bed whilst sparging.
We're going to have to agree to disagree on efficiency from both sparges. You wont see too many commercial breweries doing a batch sparge Stu & there's a good reason for it.

 

[Ducatiboy stu]

Agree on the astringency as it is common to both methods

Commercial brewers are not the same as your home setup. They have much larger volumes and things like mask rakes etc to help

 

[Crusty]

Agree on the astringency as it is common to both methods

Commercial brewers are not the same as your home setup. They have much larger volumes and things like mask rakes etc to help

The mash rake is really only used for mashing.
Raking churns the mash making sure that the grain is fully saturated so no chance of any dough balls clinging onto that precious sugar.
Commercial sparging is on the fly by two methods.
1. Spray arm
2. A measured amount of sparge liquid continuously pumped over the grain bed. Matching the pump out volume to the boil kettle with the pump rate over the grain bed.