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Reducing Sparge Volume

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Screwtop

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Wondering if other experienced brewers have experienced something similar. Possibly related more to brewers who like me fly/continuous sparge, but hey - open mic brewers. Here's the story.

I fly/continuous sparge and over the past 4 years or so as my brewing processes have improved I've needed to wind up predicted brewhouse efficiency in Beersmith to keep track of actual efficiency results. After making a batch and entering actual volumes and gravities the resulting efficiency would be higher than the set value. Next brew I would wind it up a little only to have the same result. Have left brewhouse efficiency set at 88% for the past 12 months or so as I felt this was heading somewhere that may result in reduced quality, plus I had been noticing some astringency and less maltiness in my beers. Also increasing sacch temp did not seem to help when looking to lower attenuation and or increase body/mouthfeel.

Previously I had thought low PH may have been the cause. Calcium additions to the mash took care of mash PH but if PH was rising toward the end of sparge it could increase the risk of tannin extraction. Have been lowering the PH of my sparge water to reduce this risk but the astringency, lack of body etc has continued.

Naturally as brewhouse efficiency is increased Beersmith winds back the amount of grist required to produce X gravity in X volume of wort. While the batch volume remains the same, less grist equals less water retained, which in turn results in increased sparge volume. The problem with high efficiency is this additional sparge volume.

As an example for a 45 litre batch (Ordinary Bitter 5.61 Kg grist) total brewing water required is 60.5 litres. Strike volume (@2.8L/Kg) of 16 litres leaves a huge sparge volume of 44.5 litres. This is more than 2.78 times the mash volume. I remember reading many years ago that mash/sparge water ratio should be 3:1. Mashing with a third of the pre-boil volume, leaving twice this volume for - two batch sparges. Another point of view was that you should mash with half then sparge using the other half. And John Palmer says that you should sparge with the same amount of water as you mash with. Now this concerns Batch Sparging, how about Fly Sparge? same volumes??

Checking sparge runnings during a recent batch I found runnings were down well below 1.008 with 8 litres left to run through. Stopped sparging, discarded the remaining 8 litres of runnings. Was a tad worried about the result but adding 8 litres of water pre boil met target volume and gravity. The beer was much improved on recent results, no astringency and much improved mouthfeel, roundness, maltiness.

Plan for the future was to again change my process and reduce sparge volume by 8 litres, but this time without discarding the runnings. To achieve this 8 litres of sparge water would be removed from the HLT and transferred to the kettle pre-boil maintaining total volume.

I prepare all of my brewing water the day before brewing, adding the required total volume of filtered water to the HLT. On brewday, after draining strike water to the mash tun, 8 litres would be transferred from HLT to the kettle, reducing sparge volume by 8 litres while maintaining total brewing volume, hypothetically less sparging of the grains should reduce the problem of low gravity runnings and tannin extraction.

Most of what I read years ago re continuous sparging recommended sparging until pre boil volume is achieved. So I thought why prepare more water than required, why not prepare the total volume from Beersmith, drain off strike water then for the sparge just let the remainder run through during runoff. No need to monitor!

I remember reading an article from brewer Juergen Knoeller who advised "be sure you don’t run the grain bed dry. This will start to oxidize the wort, which will lead to tannic flavors in your beer. Always keep about 1/2 inch of liquid above the grain, and be sure when you start sparging that the water is around 176 F (80 Celcius). The hot water helps deactivate the enzymes in the grain that are involved in sugar conversion. It also reduces wort viscosity and increases yield".

So could completely draining the mash tun be the cause of the astringency, maybe I need to try preparing more water than required, keeping the grist covered right through the sparge, monitoring toward the end of sparge, stopping when pre-boil volume is reached in the kettle??

Yesterday I tested the hypothesis again. Worked beautifully, not game to go with the 8 litres straight-up, transferring 6 litres instead. Hit all targets and gravities, final 3 litres of runnings 1.008, no astringency in the wort and a much fuller mouthfeel. Will reserve final judgement until this batch is carbonated and in the glass, but the previous batch is a great improvement, so fingers crossed.

Any other AG brewers experiencing this??? Over to You!

Screwy
 

razz

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I've had something similar Screwy. Since I've been using a RIMS for a year or so I've upped the mash volume and dropped the sparge volume, I hadn't noticed the problem you have, I did it purely to aid recirc through the RIMS tube and mash tun. I'm using approx 4:1 in the mash tun and I haven't checked sparge pH or gravity for some time. If what your'e doing now works then stick with that, my suggestion is to try what I did if you feel the need to, it won't cost anything to try it.
 

stux

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I've had something similar Screwy. Since I've been using a RIMS for a year or so I've upped the mash volume and dropped the sparge volume, I hadn't noticed the problem you have, I did it purely to aid recirc through the RIMS tube and mash tun. I'm using approx 4:1 in the mash tun and I haven't checked sparge pH or gravity for some time. If what your'e doing now works then stick with that, my suggestion is to try what I did if you feel the need to, it won't cost anything to try it.
I would just stop sparging sooner... so when you're runnings get to 1.010? Then you can just make up the rest of the volume with pre-boil top-up.

Oh, if you set a kettle top-up value, BS2 will subtract that from the sparge water.

Perhaps try no-sparge brewing, or biab style, put all the water in at once and bugger the l:g ratio?
 

Thirsty Boy

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When we were talking about this, I didn't quite twig that you were draining your lauter tun dry.

I'm not sure about it leading to tannic flavours - i hadn't heard that one before - usually the "dont drain the tun dry" argument is more about HSA than about anything else, and lets face it, the are enough people batch sparging and making lovely beer, who drain the tun completely, to make the "causes tannic flavours" notion a bit of a reach IMO. I could see that the added HSA in a batch sparge or fully drained lauter tun could perhaps do what HSA does and reduce the long term stability of the beer a bit - but i dont buy that it has an immediate flavour impact.

Over sparging yes.... but it'll do what it does whether you drain the tun fully or not.
 

Screwtop

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I would just stop sparging sooner... so when you're runnings get to 1.010? Then you can just make up the rest of the volume with pre-boil top-up.

Oh, if you set a kettle top-up value, BS2 will subtract that from the sparge water.

Perhaps try no-sparge brewing, or biab style, put all the water in at once and bugger the l:g ratio?

That was my original plan, however at what point do you stop draining for beers of varying pre-boil gravity. The last batch was an ordinary bitter with a pre-boil gravity of 1.027, so stopping at 1.010 would have resulted in around only half of the runnings in the kettle. Thought about this till my head hurt so decided to just stick with a set amount for all brews, that way records should provide some date for future brews. Use the kettle top up method on the previous batch, but then had to filter additional water for this. Preparing all water then just drawing off the set amount to the kettle after adding the strike water to the mash tun was easy, and I'm lazy :lol:

Want to maximise MLT space to eventually do triple batches so not about to full volume mash as in BIAB.

When we were talking about this, I didn't quite twig that you were draining your lauter tun dry.

I'm not sure about it leading to tannic flavours - i hadn't heard that one before - usually the "dont drain the tun dry" argument is more about HSA than about anything else, and lets face it, the are enough people batch sparging and making lovely beer, who drain the tun completely, to make the "causes tannic flavours" notion a bit of a reach IMO. I could see that the added HSA in a batch sparge or fully drained lauter tun could perhaps do what HSA does and reduce the long term stability of the beer a bit - but i dont buy that it has an immediate flavour impact.

Over sparging yes.... but it'll do what it does whether you drain the tun fully or not.

I agree Dan, however it's the view of a learned brewer. There would be massive differences in process time at the brewing scale he is accustomed to, so I'm prepared to believe that it can be a problem especially when brewing to maximise shelf life but not convinced that it is such a problem for the homebrewer.

Thanks for the replies,


Screwy
 

felon

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I find Jamil's Brew Strong shows very helpful.
http://thebrewingnetwork.com/shows/540
I too also find when fly sparging I chase my tail with efficiency numbers. I general drop my efficiency so that my final runnings are no where near 1.010. Usually closer to 1.016 when finishing. I check my kettle preboil sg usually about 10L before full volume and use my software to see if I can dilute with water from my HLT to bring me up to preboil volume. I use Beer Alchemy as I am a Mac user and the Iphone App has a dilution calculater on it.
 

Screwtop

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I find Jamil's Brew Strong shows very helpful.
http://thebrewingnetwork.com/shows/540
I too also find when fly sparging I chase my tail with efficiency numbers. I general drop my efficiency so that my final runnings are no where near 1.010. Usually closer to 1.016 when finishing. I check my kettle preboil sg usually about 10L before full volume and use my software to see if I can dilute with water from my HLT to bring me up to preboil volume. I use Beer Alchemy as I am a Mac user and the Iphone App has a dilution calculater on it.

Thanks felon,

Glad it's not only me. When I had eff set at 80% I would always overshoot pre-boil gravity, this is how I arrived where I am. Maybe I could do something similar, winding back eff to the point where I can stop runnings at say 1.008 and arrive at Beersmiths estimated pre-boil volume in the kettle. It seems like some of us are trying to achieve the same thing in different of ways.

Great suggestions thanks brewers,

Screwy
 

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