To Squeeze and How Much To Squeeze

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TheMadKing said:
I tried this based on your previous experiences, and I actually had about a 10% drop in brewhouse efficiency even though I ended up with the same volume measurements that you did.

I suspect that my issue is that the bag cools substantially over the course of 30 minutes and thus the concentration of sugars in the gravity drained wort is lower than in the squeezed bag wort.

I'm also combating a LHBS crusher that's set to a tradition mash/lauter crush, So I'm buying my own shortly to eliminate that variable as well and that will hopefully overcome the issue I have with hanging.
Click to expand...

TheMadKing said:
Lol no magical beans here. We have plenty of lentils here though.

I wasn't terribly clear, my crush was consistent (just on the coarse side for BIAB) but my efficiency dropped when hanging vs not hanging.

I suspect temperature because the solubility of sugar in water increases with temperature and the viscosity of the wort decreases. I could be totally wrong, and at least part of the difference could actually be the bag. I'm not using one of your bags, so my clearly inferior bag choice may be hindering may lauter efficiency :)
Click to expand...

Your reasoning has major flaws and defies the laws of physics. Squeezing or draining to the same volume all else being equal will have zero difference in the sugars in the kettle all else being equal. You are 100% barking up the wrong tree in your reasoning here.

The solubility limit of sugar in water is far far far beyond the reaches of any kind of gravity resulting in brewing. All sugars present are in solution. The SG of the wort in the kettle and the wort in the hanging/squeezed bag are identical.

Think syrup or LME. All the sugars are in solution.

Draining or squeezing makes no difference to mash efficiency assuming equal volumes, grain-bill, crush etc. All other factors need to be identical. Clearly they were not hence the difference in the numbers.
 
Gavin C said:
Your reasoning has major flaws and defies the laws of physics. Squeezing or draining to the same volume all else being equal will have zero difference in the sugars in the kettle all else being equal. You are 100% barking up the wrong tree in your reasoning here.

The solubility limit of sugar in water is far far far beyond the reaches of any kind of gravity resulting in brewing. All sugars present are in solution. The SG of the wort in the kettle and the wort in the hanging/squeezed bag are identical.

Think syrup or LME. All the sugars are in solution.

Draining or squeezing makes no difference to mash efficiency assuming equal volumes, grain-bill, crush etc. All other factors need to be identical. Clearly they were not hence the difference in the numbers.
Click to expand...

Thanks got that already, see above.
 
Gavin C said:
Yeah. Just posted before reading the rest of the thread. Sorry 'bout that, didn't mean to pound the point home more than it had already been pounded.
Click to expand...

No worries, happens to me all the time.

So now that we've established that I'm dead wrong about my hypothesis, I have some questions.

Do you assume 100% lautering efficiency for all BIAB methods?

If so, how do you account for people who boost efficiency with a dunk or pour-over sparge? It seems to me like that is effectively flushing more sugars from the grains by the sparge water displacing any sugar laden water in the wet grain. But, as we are all squeezing or hanging, it shouldn't really matter whether you dunk sparge or not since the grain absorption of BIAB is minimal (I usually see about .05-.08 L/lb of grain)

If sparging methods do not improve efficiency of BIAB, then really the only things I should worry about are crush, mash length, and pH?

Dialing in my efficiency to a consistent number on my system is something I'm struggling with currently, so any advice is appreciated.
 
TheMadKing said:
No worries, happens to me all the time.

So now that we've established that I'm dead wrong about my hypothesis, I have some questions.

Do you assume 100% lautering efficiency for all BIAB methods?

If so, how do you account for people who boost efficiency with a dunk or pour-over sparge? It seems to me like that is effectively flushing more sugars from the grains by the sparge water displacing any sugar laden water in the wet grain. But, as we are all squeezing or hanging, it shouldn't really matter whether you dunk sparge or not since the grain absorption of BIAB is minimal (I usually see about .05-.08 L/lb of grain)

If sparging methods do not improve efficiency of BIAB, then really the only things I should worry about are crush, mash length, and pH?

Dialing in my efficiency to a consistent number on my system is something I'm struggling with currently, so any advice is appreciated.
Click to expand...

Sparging does improve efficiency. For no-sparge and batch sparge, it is possible to calculate the lauter efficiency. The chart below compares no-sparge to equal runnings volume batch sparge for different grain bill weights for several different grain absorption rates. 6.7 gal pre-boil volume is assumed for all cases, as is zero MLT dead volume (standard for BIAB.)

BIAB No Sparge vs Sparge big beers.png

Brew on :mug:
 
@madking

No not assuming 100%lauter efficiency with any method. That would be totally wrong and a physical impossibility.

BIAB. The fundamentals are identical wrt mashing sparging.

Strive for very close to 100% conversion efficiency and your mash efficiency will be largely dictated by lauter ing efficiency. Some sugars will always remain in the mash regardless of method.
 
doug293cz said:
Sparging does improve efficiency. For no-sparge and batch sparge, it is possible to calculate the lauter efficiency. The chart below compares no-sparge to equal runnings volume batch sparge for different grain bill weights for several different grain absorption rates. 6.7 gal pre-boil volume is assumed for all cases, as is zero MLT dead volume (standard for BIAB.)

View attachment 333399

Brew on :mug:
Click to expand...

awesome graph doug, thank you, that cleared up a lot of my confusion.

Now I'm curious as to the actual physical mechanism behind why sparging increases efficiency for a given grain absorption and grain bill. Effectively, where is the sugar hiding that requires a sparge instead of just water removal to get it out, and what physical form is it in?

It cannot be a solute otherwise it would drain out with the wort during a no-sparge. I can only infer that it must be still contained within the grain kernals or on their surfaces as a solid or semi-solid. If that is the case, then it would seem that the temperature of the sparge water would affect the rate of dissolution of these residual sugars, which Brukaiser's experiment shows is false.

These are mostly just curiosity questions, since the actual practice of HOW to get the sugars out is well understood.

I will be making a Vienna lager this weekend and I'll do a dunk sparge and long drain and see how it goes since I still don't have positive control over my crush.
 
Sparging increases efficiency because it further dilutes the sugars that remain in the wort that is absorbed by the grain. In a no sparge, the sugar content of the absorbed wort will be the same as the collected wort, sparging will reduce this and improve efficiency. This becomes more significant as gravity increases.

The sugars that remain are in solution in the wort that is absorbed by the grain, and to retrieve all the liquid would be 100% lauter efficiency, there is no solid sugar.

Simply put, with a sparge you are rinsing more, not dissolving more.
 
TheMadKing said:
awesome graph doug, thank you, that cleared up a lot of my confusion.

Now I'm curious as to the actual physical mechanism behind why sparging increases efficiency for a given grain absorption and grain bill. Effectively, where is the sugar hiding that requires a sparge instead of just water removal to get it out, and what physical form is it in?

It cannot be a solute otherwise it would drain out with the wort during a no-sparge. I can only infer that it must be still contained within the grain kernals or on their surfaces as a solid or semi-solid. If that is the case, then it would seem that the temperature of the sparge water would affect the rate of dissolution of these residual sugars, which Brukaiser's experiment shows is false.

These are mostly just curiosity questions, since the actual practice of HOW to get the sugars out is well understood.

I will be making a Vienna lager this weekend and I'll do a dunk sparge and long drain and see how it goes since I still don't have positive control over my crush.
Click to expand...

The sugar is all dissolved in water, since it is created from starch that is either dissolved or gelatinized. Solid sugar never exists in the mash.

The grain bed is like a sponge. If you have a sponge in a bowl of water, and pour off the water, there is still a significant amount of water in the sponge. If you squeeze the sponge, you get some of the residual water out.

Now let's put the sponge in a bowl of sugar water. After draining off the liquid, the sponge still contains some sugar water, and thus some sugar. If you add more water to the bowl, and squeeze the sponge a lot, you can equalize the concentration of sugar between what was in the sponge and the added water. Now when you pour the water out of the bowl, the sponge contains about the same amount of liquid that it did the first time you drained the bowl, but a lot less sugar.

Now let's do the same thought experiment, but without the sponge, and this time we'll throw in some numbers to make it quantitative. Let's say we have a container with 10 gal of liquid that is 10% sugar. If we pour off 9 gal, we still have 1 gal of liquid in the container that is 10% sugar.

If instead of starting with 10 gal of 10% solution, we start with 5 gal of 20% solution, and pour off 4 gal, we have 1 gal of 20% solution left in the container. If we add 5 gal of water to the container and mix well, we have 6 gal of 3.33% sugar. Now we pour off 5 gal of the 6 gal, leaving 1 gal of 3.33% sugar solution in the container.

The second process leaves only 1/3 as much sugar in the container, thus more sugar is in the drained solution. We had the same total volume of solution, and the same volume of total draining, but got more of the original sugar in the drainings than the one step process. That's how sparging works.

The above is a little over simplified since it ignores the details about specific gravity, but it demonstrates what is going on with sparging. The simulations I used to make the chart take into account all of the gory details.

Brew on :mug:
 
doug293cz said:
The sugar is all dissolved in water, since it is created from starch that is either dissolved or gelatinized. Solid sugar never exists in the mash.

The grain bed is like a sponge. If you have a sponge in a bowl of water, and pour off the water, there is still a significant amount of water in the sponge. If you squeeze the sponge, you get some of the residual water out.

Now let's put the sponge in a bowl of sugar water. After draining off the liquid, the sponge still contains some sugar water, and thus some sugar. If you add more water to the bowl, and squeeze the sponge a lot, you can equalize the concentration of sugar between what was in the sponge and the added water. Now when you pour the water out of the bowl, the sponge contains about the same amount of liquid that it did the first time you drained the bowl, but a lot less sugar.

Now let's do the same thought experiment, but without the sponge, and this time we'll throw in some numbers to make it quantitative. Let's say we have a container with 10 gal of liquid that is 10% sugar. If we pour off 9 gal, we still have 1 gal of liquid in the container that is 10% sugar.

If instead of starting with 10 gal of 10% solution, we start with 5 gal of 20% solution, and pour off 4 gal, we have 1 gal of 20% solution left in the container. If we add 5 gal of water to the container and mix well, we have 6 gal of 3.33% sugar. Now we pour off 5 gal of the 6 gal, leaving 1 gal of 3.33% sugar solution in the container.

The second process leaves only 1/3 as much sugar in the container, thus more sugar is in the drained solution. We had the same total volume of solution, and the same volume of total draining, but got more of the original sugar in the drainings than the one step process. That's how sparging works.

The above is a little over simplified since it ignores the details about specific gravity, but it demonstrates what is going on with sparging. The simulations I used to make the chart take into account all of the gory details.

Brew on :mug:
Click to expand...

Awesome explanation and metaphor, thanks for taking the time to type all that up. I understand why it works now, so I can start making improvements to my system.

I wonder (and maybe you've already examined this) how much crush size is affecting the water retention in the grain and therefore increasing the need for sparging vs how much the crush affects conversation efficiency and reduces actual total sugars in solution.

Since traditional mashing and lautering use a larger crush and can maintain higher efficiencies, I would initially suspect the former.
 
TheMadKing said:
Awesome explanation and metaphor, thanks for taking the time to type all that up. I understand why it works now, so I can start making improvements to my system.

I wonder (and maybe you've already examined this) how much crush size is affecting the water retention in the grain and therefore increasing the need for sparging vs how much the crush affects conversation efficiency and reduces actual total sugars in solution.

Since traditional mashing and lautering use a larger crush and can maintain higher efficiencies, I would initially suspect the former.
Click to expand...

Glad it was helpful.

I have not looked at crush size vs. absorption rate, and am not aware of anyone who has. For traditional MLT's the limited range of useful crush sizes probably limits this effect. For BIAB, the absorption rate is so dependent on aggressiveness of squeezing, that any general rule would not apply most of the time.

BIAB with aggressive squeezing and a sparge can beat traditional 3 vessel plus batch sparge due primarily to lower grain absorption, and secondarily due to better conversion efficiency from the finer grind.

Brew on :mug:
 
I hang it and almost always hit my volume and gravity # keep it simple that's what BIAB is all about....seems like to many are making BIAB more complicated in the last couple years to me...one vessel & a bag for me...
 
browder said:
I hang it and almost always hit my volume and gravity # keep it simple that's what BIAB is all about....seems like to many are making BIAB more complicated in the last couple years to me...one vessel & a bag for me...
Click to expand...

That's the beauty of homebrewing. There are lots of ways to do it, from simple to complex, and they all work! Just about anyone can find a process that meets their needs for simplicity, elegance, control, gadgetry, complexity... whatever floats their boat. Eventually most brewers arrive at the process that's right for them.

Brew on :mug:
 
I always squeeze to "hit my numbers". But reading through this, the only numbers I need to concern myself with is volume. If the gravity in the wort is the same as the gravity in the wet grain then just let it hang until volume is reached.

I would squeeze till it hurt THEN take my gravity reading. I should just take gravity then wait for the volume to be reached. If my calculations are correct in Beersmith then it should all work out.
 
doug293cz said:
That's the beauty of homebrewing. There are lots of ways to do it, from simple to complex, and they all work! Just about anyone can find a process that meets their needs for simplicity, elegance, control, gadgetry, complexity... whatever floats their boat. Eventually most brewers arrive at the process that's right for them.

Brew on :mug:
Click to expand...

Thanks for your input on this. Never thought my thread would get this many responses and opinions.

Being just a beginner at BIAB I was trying to get my mash efficience above my first batch which was 88%. Now I see there is more to it. After looking at my third batch numbers it appears all I got was a lower grain absorption number .06. I used a finer crush, a double run at .03 versus .04 for my first batch and I did a 90 minute mash compared to a 60 minute. My gravity readings didn't improve much at all. They went from 1.040 at the 60 minute mark to 1.047 at 90 minutes. My volume after squeezing with my board setup went from 7.75 gallons to 8.35 gallons. Note I was over on my initial water amount because I did not have the proper boil off rate. The boards made it easier and got more out of the grains.

I'm thinking of now trying some type of sparger to see what it will do to my numbers which from what I read should increase. Now the million dollar question. What would be my best option.

A dunk type or what I would think would be easier would be to lift the bag out of the wort, open it up and poor the sparge water over the grain. Now the other part of the question, how much water?

Thanks all.
 
Well the "how much water" I can answer

Desired preboil volume + expected grain absorption - sparge water = mash water

The actual amount of sparge water is up to you, just make sure you have enough mash water to be over ~1.5qt/lb of grain (thinner is better)
 
Bigarcherynut said:
. Now the million dollar question. What would be my best option.

A dunk type or what I would think would be easier would be to lift the bag out of the wort, open it up and poor the sparge water over the grain. Now the other part of the question, how much water?

Thanks all.
Click to expand...

I've done both. Your preference will probably depend on your set up. If you've got a way to hoist the bag, open it and pour sparge water over, then that's the way I'd go. I found there was a lot more manual labor involved with dunk sparge than this method.

Concerning how much water to use, just keep pouring water over the top until you hit your volume. Then move the bag to the side. You don't even need to know your grain absorption rate!
 
Don't use beersmith I use priceless cacultor it works give or take a quart...there are alotta different ways of doing things & I have tried several but when I have kettle Rollin I end up with a garage full of people and simple works best for me....I have sqeezed duncked & every other thing but the string works for me & I don't let it hang all that long to get volume...kinda like cooking it always good & never quite the same and I'm totally good with that...
 
TheMadKing said:
Well the "how much water" I can answer

Desired preboil volume + expected grain absorption - sparge water = mash water

The actual amount of sparge water is up to you, just make sure you have enough mash water to be over ~1.5qt/lb of grain (thinner is better)
Click to expand...

Thanks.

I have been using the Priceless calculator. I just enetered the amounts for my last batch and if I enter 2 gallons for sparge it will still give me the same amount for "Total Water Needed". I imagine that I need to subtract the 2 gallons from that and that would give me my starting amount and still be at 1.69 qt./lb.

Now with the starting amount being 2 gallons less, that has to affect the strike temp?? May need to adjust for that.
 
TexasWine said:
I've done both. Your preference will probably depend on your set up. If you've got a way to hoist the bag, open it and pour sparge water over, then that's the way I'd go. I found there was a lot more manual labor involved with dunk sparge than this method.

Concerning how much water to use, just keep pouring water over the top until you hit your volume. Then move the bag to the side. You don't even need to know your grain absorption rate!
Click to expand...

I do have a pulley system. All I need to do is make a spreader to hold the bag open and I'm good to go. Is 168 degree the normal for sparge water? Using the Priceless calculator that's the default temp.

Thanks.
 
wilserbrewer said:
I find just patiently letting the bag drain over the kettle for 20-30 minutes yields all but a few ounces.
Click to expand...
I'm a patient drainer too; and I like to think it promotes WilserBrewerBag longevity.

Gavin C said:
Don't squeeze. Spin.
Click to expand...

This. Is. AWESOME idea. We just need one of them late night TV Ronco 15# wet grain sized salad spinners.
Starfrit-Salad-Spinner1-611x415.jpeg
Or, feeling adventurous, risking life, limb and the need to sleep on the couch for the rest of our marriage, try using the washing machine spin cycle...
 
Bigarcherynut said:
Thanks.

I have been using the Priceless calculator. I just enetered the amounts for my last batch and if I enter 2 gallons for sparge it will still give me the same amount for "Total Water Needed". I imagine that I need to subtract the 2 gallons from that and that would give me my starting amount and still be at 1.69 qt./lb.

Now with the starting amount being 2 gallons less, that has to affect the strike temp?? May need to adjust for that.
Click to expand...

Yes, your strike temp will need to be higher because your strike water has less volume (and therefore mass) to retain heat.
 
TheMadKing said:
Yes, your strike temp will need to be higher because your strike water has less volume (and therefore mass) to retain heat.
Click to expand...

With that, I may be able to use the numbers the program gives me. Currently with my setup it's been a bit high. Next batch I'll try the strike temp given and see how it works.
 
Bigarcherynut said:
With that, I may be able to use the numbers the program gives me. Currently with my setup it's been a bit high. Next batch I'll try the strike temp given and see how it works.
Click to expand...

With the priceless calculator there is a field for sparge water, so as long as everything else is accurate and you put your 2 gallons of sparge water in there, your strike water temp should be fairly accurate.
 
I don't mean to take this thread in a different direction but I feel there are people posting on this thread that could answer this.

Seeing I'm new to all grain and BIAB I've been doing some reading on this but want to know your feelings. I'm understanding some on unfermentables in the wort. With what I've read my longer mash times will create a sweeter beer. Since I'm brewing Porters and a Stout now I'm not worried. What I'm seeing is my FG's are not getting below 1.028 with an OG of 1.07's and 1.064. I don't have my old frig converted to a fermenter yet so working at keeping my temps right on the 3 fermenters. Could this be just the unfermentables keeping the gravity readings up? The way it's looking my ABV will be lower than when I did these recipes with extract.

Thanks.
 
TheMadKing said:
With the priceless calculator there is a field for sparge water, so as long as everything else is accurate and you put your 2 gallons of sparge water in there, your strike water temp should be fairly accurate.
Click to expand...

See it now. Was thinking backwards. Less water higher strike temp needed.

Thanks.
 
Bigarcherynut said:
I don't mean to take this thread in a different direction but I feel there are people posting on this thread that could answer this.

Seeing I'm new to all grain and BIAB I've been doing some reading on this but want to know your feelings. I'm understanding some on unfermentables in the wort. With what I've read my longer mash times will create a sweeter beer. Since I'm brewing Porters and a Stout now I'm not worried. What I'm seeing is my FG's are not getting below 1.028 with an OG of 1.07's and 1.064. I don't have my old frig converted to a fermenter yet so working at keeping my temps right on the 3 fermenters. Could this be just the unfermentables keeping the gravity readings up? The way it's looking my ABV will be lower than when I did these recipes with extract.

Thanks.
Click to expand...

The amount if unfermentables in your wort is more related to the grain bill and adjuncts that you use.

Usually high FG's like that are a result of recipes using too much crystal malt or lactose.

The length of mash shouldn't affect your fermentability much, but your mash temperature does. A longer mash can boost conversion efficiency though

A higher mash temperature (152-158F) will result in more complex starches and fewer simple sugars, while a cooler mash temp (146-151F) will result in a highly fermentable wort.

So if you do a 90 minute mash at 153F you're going to end up with a medium- to - full bodied beer with a higher FG than if you did a 90 minute mash at 149F.

Does that answer your question?
 
Bigarcherynut said:
I do have a pulley system. All I need to do is make a spreader to hold the bag open and I'm good to go. Is 168 degree the normal for sparge water? Using the Priceless calculator that's the default temp.

Thanks.
Click to expand...

Hot (168°F) or cold, doesn't matter. It won't impact efficiency. The advantage of going with hot sparge is that it's a faster brew day compared to doing to cold sparge.
 
TheMadKing said:
The amount if unfermentables in your wort is more related to the grain bill and adjuncts that you use.

Usually high FG's like that are a result of recipes using too much crystal malt or lactose.

The length of mash shouldn't affect your fermentability much, but your mash temperature does. A longer mash can boost conversion efficiency though

A higher mash temperature (152-158F) will result in more complex starches and fewer simple sugars, while a cooler mash temp (146-151F) will result in a highly fermentable wort.

So if you do a 90 minute mash at 153F you're going to end up with a medium- to - full bodied beer with a higher FG than if you did a 90 minute mash at 149F.

Does that answer your question?
Click to expand...

Yes it does. Perfect.

Thanks Much!
 
Bigarcherynut said:
I'm thinking of now trying some type of sparger to see what it will do to my numbers which from what I read should increase. Now the million dollar question. What would be my best option.

A dunk type or what I would think would be easier would be to lift the bag out of the wort, open it up and poor the sparge water over the grain. Now the other part of the question, how much water?

Thanks all.
Click to expand...

Surprisingly, you don't need to open the bag to pour sparge water over the grain. The bag is so pourous that merely slowly pouring water over the top of the grain bag nicely runs rught through the grain. I was surprised how well this works, I anticipated the water cascading over the outside of the bag, but it doesn't.

With regards to "how much water", it is much easier to sparge to a desired volume than calculate, or should we say approximate it....sorry priceless :)

I tend to use a pour over sparge more as a preboil volume adjustment rather than a means to improve "chase efficency" :D
 

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