Mash Thickness and Efficiency

[doug293cz]

I can't get his to work, but it appears to be for BIAB anyway - not sure if the metrics are the same? In any case, yours seems better...

Did you see our questions about how to account for added sugar to the boil?

When I used your calculator I got a predicted OG of 1.085. But that was without the 2 lbs of D-180. Not sure how many points I'd get from that sugar, but I'm guessing it would now put me over my target OG of 1.088.

The Priceless calculator started out intended for BIAB, but evolved into something that could be used for either BIAB or single batch sparge. If you want to use it for a traditional MLT, then you should at least increase the grain absorption rate to 0.12 gal/lb, as 0.08 gal/lb is only valid for a very well drained bag, with a light squeeze.

I'll write another post for the added sugar question, as that is a very involved answer.

Brew on

 

[VikeMan]

When I used your calculator I got a predicted OG of 1.085. But that was without the 2 lbs of D-180.

D-180 will add about 32 points per pound per gallon. Let's say you'll have 5 gallons of wort post boil, including the two pounds of D-180. The two pounds of D-180 will be providing 64 "points." Those points will be distributed throughout 5 gallons of wort, so...

64 / 5 = 12.8 points. (Round to 13 gravity points.) So, if your wort would have had a post boil OG of 1.085, the OG including the syrup would be about 1.085 + .013 = 1.098 (at 5 gallons).

But there's a catch. The 2 lbs of candi syrup will also add about 0.1625 gallons of volume, so if you just add it to the same wort that would have hit 5 gallons post boil without the syrup, you'll have 5.1625 gallons. And the gravity would be a little lower:

98 x (5 / 5.1625) = ~95 , so 1.095

If you wanted to hit 1.098 @ 5 gallons (and not 1.095 @ 5.1625 gallons), you'd need to boil longer or use less total water.

 

[SRJHops]

D-180 will add about 32 points per pound per gallon. Let's say you'll have 5 gallons of wort post boil, including the two pounds of D-180. The two pounds of D-180 will be providing 64 "points." Those points will be distributed throughout 5 gallons of wort, so...

64 / 5 = 12.8 points. (Round to 13 gravity points.) So, if your wort would have had a post boil OG of 1.085, the OG including the syrup would be about 1.085 + .013 = 1.098 (at 5 gallons).

But there's a catch. The 2 lbs of candi syrup will also add about 0.1625 gallons of volume, so if you just add it to the same wort that would have hit 5 gallons post boil without the syrup, you'll have 5.1625 gallons. And the gravity would be a little lower:

98 x (5 / 5.1625) = ~95 , so 1.095

If you wanted to hit 1.098 @ 5 gallons (and not 1.095 @ 5.1625 gallons), you'd need to boil longer or use less total water.

Thanks. Let me chew on that for a bit.. Is there a way to account for it in the calculator?

It would appear that I should actually reduce my grain if I want to hit 1.088 OG.

 

[doug293cz]

Cool - I am giving it a go! If I already have a target grain amount I don't need to use the Goal Seek function, correct? (If I still need to use the Goal Seek function, I am having trouble understanding where it is located on the spreadsheet.)

Why would you start with a target grain amount if building a recipe? Most times you would start with a target OG and target volume, and want to figure out how much grain and water you need to get there, based on your particular process specifics. If you are doing a post-brew diagnostic analysis, then you have a fixed grain amount.

P.S. I put in .25 gallons undrainable for the MLT. Maybe I shoul

MLT undrainable volume is not what you leave behind by choice. It is the volume left behind in the bottom of the MLT, and any plumbing, when you have transferred as much to the BK as your equipment allows. The calculations assume you are not intentionally leaving any volume behind on any of the run-offs.

Brew on

 

[doug293cz]

Is there a way to account for it in the calculator?

Not in the current version. It wouldn't be too hard to add for things added by weight, but also making it work for things added as liquid (fruit juice for example), would make things much more complicated. And, it you wanted both by weight and by volume additions in the same brew, that would be a real mess to deal with.

Brew on

 

[SRJHops]

Why would you start with a target grain amount if building a recipe? Most times you would start with a target OG and target volume, and want to figure out how much grain and water you need to get there, based on your particular process specifics. If you are doing a post-brew diagnostic analysis, then you have a fixed grain amount.



MLT undrainable volume is not what you leave behind by choice. It is the volume left behind in the bottom of the MLT, and any plumbing, when you have transferred as much to the BK as your equipment allows. The calculations assume you are not intentionally leaving any volume behind on any of the run-offs.

Brew on

I have the grain amount from the recipe software. I was looking for a water volume calculator. So, I would actually be using 3 calculators now: recipe, water volume, water additions/ph.

It did just occur to me that for your spreadsheet, my target OG is not the final OG. I should see what the recipe calculator would give for SG's for the wort without the sugar. Then I can add the sugar back in... I'll tinker around with it. Thanks for the cool calculator!

Re MLT: it had 0 for the loss, so I wanted to put something in.

P.S. Thanks to you and all who commented! My process will get better thanks to your help. Much appreciated!

 

[doug293cz]

D-180 will add about 32 points per pound per gallon. Let's say you'll have 5 gallons of wort post boil, including the two pounds of D-180. The two pounds of D-180 will be providing 64 "points." Those points will be distributed throughout 5 gallons of wort, so...

64 / 5 = 12.8 points. (Round to 13 gravity points.) So, if your wort would have had a post boil OG of 1.085, the OG including the syrup would be about 1.085 + .013 = 1.098 (at 5 gallons).

But there's a catch. The 2 lbs of candi syrup will also add about 0.1625 gallons of volume, so if you just add it to the same wort that would have hit 5 gallons post boil without the syrup, you'll have 5.1625 gallons. And the gravity would be a little lower:

98 x (5 / 5.1625) = ~95 , so 1.095

If you wanted to hit 1.098 @ 5 gallons (and not 1.095 @ 5.1625 gallons), you'd need to boil longer or use less total water.

The rigorous way to calculate the effect of fermentables added to the boil is to do a mass balance on the water and sugar (actually extract or total dissolved solids.) In this case you don't need to know the volume of items added by weight.

In the case of D-180 you know the total weight and pts/lb (32.) You can convert pts/lb to % sugar by dividing by 46.173 (which is the pts/lb of pure sucrose.) So, D-180 is 32 / 46.173 = 0.693 or 69.3 wt% sugar. Therefore 1.0 lb of D-180 is 0.693 lb of sugar and 0.307 lb of water.

My spreadsheet calculates the total weight of the wort in the BK, the weight of extract in the BK, and the weight of water in the BK after mash and lauter. Weight of wort = weight of extract + weight of water.

The original Plato of the wort in the BK is: 100 * Weight of Extract in BK / Weight of Wort in BK. Which is the same a weight percent of extract in the BK.

To calculate the Plato after an addition to the BK you use the following formula:

New Plato = 100 * (Original Extract Wt + Added Extract Wt) / (Original Wort Wt + Addition Wt)​

​

In @SRJHops case* my spreadsheet gives original extract wt in BK as 10.392 lb, and original wort wt in BK as 63.548 lb, and the original Plato as 16.35 (or 1.0670 SG.) So, the new Plato will be:

New Plato = 100 * (10.392 + 2 * 0.693) / (63.548 + 2 * 1) = 100 * 11.778 / 65.548 = 17.97​

​

You can use the following formula to convert Plato to SG:

SG = 1 + (Plato / (258.6 - ((Plato / 258.2) * 227.1)))​

​

So, the pre-boil SG, after addition, would be 1.0740.

After boiling off 1.65 gal or 1.65 gal * 8.3304 lb/gal = 13.745 lb of water, the OG without the D-180 addition would be 100 * 10.392 / (63.548 - 13.745) = 20.87 or 1.0869 SG. After boiling off the same 1.65 gal the OG with the D-180 addition would be 100 * 11.778 / (65.548 - 13.745) = 22.74 or 1.0953 SG.

* My numbers will be a little different as I don't know exactly what @SRJHops 's inputs to my spreadsheet were, but I should be pretty close.

Brew on

 

[mashdar]

A thought experiment regarding large grain bills and a 5 gallon post boil:

Case #1: Imagine you have 10# of grain and a pre-boil target of 7 gallons. You mash and lauter and get 80% lauter efficiency.

Case #2: Now you decide to only mash and sparge with 3.5 gallons collected, then top off the first wort with 3.5 gallons water to hit your 7 gallons pre-boil.

Do you expect the same efficiency in case #2? Of course not.

Case #3, instead of cutting the 7 gallons collected water in half, you double the grain bill to 20#. This is equivalent to a double batch of Case #2, except not watering it down. Do you expect to match case #1 efficiency? Again, of course not.

Case #4: 20# grain and collect 14 gallons. This is basically a double batch of Case #1, but get ready because you're going to need to boil off 9 gallons to hit the 5 gallon post-boil target.

Hopefully this illustrates why efficiency is always going to be negatively correlated with grain bill, all else being equal. It's pretty inevitable unless you plan on a long boil.

 

[Uke733]

Perhaps it's time to plug my Mash and Lauter Simulator spreadsheet again. You can use this sheet to make predictions of your efficiency based on recipe and process, or even (using "Goal Seek") to tell you how much grain you need to hit a given OG! To use the spreadsheet, you need to download a copy as either an Excel or LibreOffice format sheet, and work with the local copy.

Here's what the input section looks like

Brew on

Thanks for sharing this work @doug293cz. Very useful learning tool.

Pretty sure there is something silly I am missing! My question is about spreadsheet results as is (zero sparge steps).

Why does the Mash total wort sg of 42.9 x ~7.71 gals = 330 not equal 355? Or asked another way, where did the 25 ppg go?

 

[doug293cz]

Thanks for sharing this work @doug293cz. Very useful learning tool.

Pretty sure there is something silly I am missing! My question is about spreadsheet results as is (zero sparge steps).

Why does the Mash total wort sg of 42.9 x ~7.71 gals = 330 not equal 355? Or asked another way, where did the 25 ppg go?

When doing ppg calculations you have to use wort volume, not water volume. 7.7gal is the strike water volume. The actual wort volume is more than that due to the volume added by the dissolved extract. The wort contains 64.259 lb of water and 7.693 lb of extract, for a total wort weight of 71.952 lb. The volume is then 71.952 / (8.3304 * 1.0429) = 8.28 gal. 8.28 gal * 42.9 pt/gal = ~355 total pts. Using strike water volume rather than actual mash wort volume is a common mistake.

Brew on

 

[MicroMickey]

https://crescentcitybrewtalk.com/mash-thickness/
Road maps have lots of lines on them because there are many ways to get where you want to be. The above link explains my thoughts on mash thickness. As stated in previous posts, mash thickness is really all about the enzymes - what does it take to make them happy?

 

[mashdar]

https://crescentcitybrewtalk.com/mash-thickness/
Road maps have lots of lines on them because there are many ways to get where you want to be. The above link explains my thoughts on mash thickness. As stated in previous posts, mash thickness is really all about the enzymes - what does it take to make them happy?

Is it still thought that thicker mashes protect amy enzymes from deactivation? Rings a 15yo+ bell. Palmer?

 

[doug293cz]

Is it still thought that thicker mashes protect amy enzymes from deactivation? Rings a 15yo+ bell. Palmer?

Don't know for sure, but Braukaiser has shown that thinner mashes convert faster, so you want the enzymes to last longer in thicker mashes.

Brew on

 

[Junker Jörg]

for what it’s worth, I MIAB with full volume, no sparge, and usually hit about 80%. I mill pretty fine

 

[dmaxweb]

I have a direct fired mash tun and recirculate continously. When I calculate mash thickness, do I count the volume under the false bottom? I brew 10 gallon batches and the volume under the false bottom is 1.6 gallons

 

[day_trippr]

I would not count the recoverable dead space volume when calculating mash thickness...

ChatGPT agrees, fwiw

"When calculating brewing mash thickness, the recoverable dead space volume is typically not included. Mash thickness, also known as the liquor-to-grist ratio, refers to the amount of water used relative to the amount of grain in the mash."



Cheers!

 

[doug293cz]

I have a direct fired mash tun and recirculate continously. When I calculate mash thickness, do I count the volume under the false bottom? I brew 10 gallon batches and the volume under the false bottom is 1.6 gallons

I would not count the recoverable dead space volume when calculating mash thickness...

ChatGPT agrees, fwiw

"When calculating brewing mash thickness, the recoverable dead space volume is typically not included. Mash thickness, also known as the liquor-to-grist ratio, refers to the amount of water used relative to the amount of grain in the mash."



Cheers!

If you are concerned about thickness as it affects stirring the mash, then don't count the water under the false bottom, or between the side wall of a malt pipe and the vessel wall.

If you are going to calculate conversion efficiency, then you count all of the strike water in your mash thickness. If you have wort outside of the grain mass, then you have to do whatever it takes to homogenize all of the wort before taking a mash wort SG reading to use in subsequent calculations. This may only require recirculating in the case of a false bottom, but with a malt pipe you need to lift and lower the malt pipe repeatedly to homogenize all of the wort.

Brew on

 

[DuncB]

but with a malt pipe you need to lift and lower the malt pipe repeatedly to homogenize all of the wort.

Do not lift and lower the malt pipe on systems with removable bottoms to the maltpipes ( grainfather, brewzilla etc) I did this and the hydrostatic pressure pushed up the base, grain fell out and chaos.

If you have a sight glass and recirculate your mash with these malt pipe systems to run them with only the "dead space" below the malt pipe filled you'll eliminate the the between malt pipe and kettle volume, another option is to use the whirlpool at the same time as recirculating this will mix the malt pipe to wall dead space liquid and also provide better circulation over the temp sensor which on most all in ones is positioned in the kettle base and not near the outflow. You will get much better temperature stability this way.
Or do both of the above tricks at once, my system has 9 litres of volume below the malt pipe I can with care run it with 6 litres and then there's more usable liquid for mash or to sparge with.

 

[doug293cz]

Do not lift and lower the malt pipe on systems with removable bottoms to the maltpipes ( grainfather, brewzilla etc) I did this and the hydrostatic pressure pushed up the base, grain fell out and chaos.

If you have a sight glass and recirculate your mash with these malt pipe systems to run them with only the "dead space" below the malt pipe filled you'll eliminate the the between malt pipe and kettle volume, another option is to use the whirlpool at the same time as recirculating this will mix the malt pipe to wall dead space liquid and also provide better circulation over the temp sensor which on most all in ones is positioned in the kettle base and not near the outflow. You will get much better temperature stability this way.
Or do both of the above tricks at once, my system has 9 litres of volume below the malt pipe I can with care run it with 6 litres and then there's more usable liquid for mash or to sparge with.

I don't get how you are running with only 6L below the malt pipe, if the volume below the malt pipe is 9L.

Yes, if you split your recirc flow between the top of the malt pipe and the volume outside the malt pipe, you can homogenize the wort without having to resort to lifting the malt pipe. You should do some testing to insure that whatever recirc arrangement you come up with actually does involve the total volume of liquid in the recirc.

Brew on

 

[DuncB]

@doug293cz

I don't always run my system with so little below the malt pipe, the sight glass indicates how much liquid is in the bottom of the all in one and the rest of the liquid is either on top of the grains in the malt pipe or seeping down. This lowered running dead space tends to only occur if I'm doing a very thick mash. There is a gap between the malt pipe base and the top of the liquid during these situations. The whirlpool arm also gives an audible indication that the level is getting low because I can hear it burbling away. But you have to be very careful until equilibrium is reached, I don't have an automatic level detector to slow the recirculation down.

I'm pretty sure that the liquid is all being used in the recirculation and overall efficiency of mash and lauter has improved with these modifications.
But I'll keep an eye on the numbers Thank you.

 

[doug293cz]

@doug293cz

I don't always run my system with so little below the malt pipe, the sight glass indicates how much liquid is in the bottom of the all in one and the rest of the liquid is either on top of the grains in the malt pipe or seeping down. This lowered running dead space tends to only occur if I'm doing a very thick mash. There is a gap between the malt pipe base and the top of the liquid during these situations. The whirlpool arm also gives an audible indication that the level is getting low because I can hear it burbling away. But you have to be very careful until equilibrium is reached, I don't have an automatic level detector to slow the recirculation down.

I'm pretty sure that the liquid is all being used in the recirculation and overall efficiency of mash and lauter has improved with these modifications.
But I'll keep an eye on the numbers Thank you.

Ok, I thought that's what you might be doing, but was unsure. Seems like you would need to be very vigilant to make sure you don't pump the bottom area dry, and end up dry firing the heating elements. Sounds like an inherently unstable system, and personally I like to deal with systems that have what is known as static or positive stability.

Brew on

 

[Uke733]

View attachment 812772
Brew on

Hmm, I realize this is an old post, but figure it was the best context for this question. I struggled trying to make the question clear...er...est....

Assuming we are fly sparging, stopping at 1.008, 1.25 qt/lb mash thickness (limitation of my system) and need to boil for an hour (even a zero boil wouldn't matter for this question). Then there is no way to achieve a low SG beer like 1.032 without adding water after the sparge?

Overtime I am reducing my boiling time, boil vigor and OG. Probably a "getting older" affect but, I often see these recipes with really low SG and don't think they are possible without over sparging, or is it common knowledge that everyone adds water? Or am I just missing something?

 

[sibelman]

achieve a low SG beer like 1.032 without adding water

Can't you simply use less malt to get lower OG/SG? I must be missing something.

 

[Uke733]

Can't you simply use less malt to get lower OG/SG? I must be missing something.

No, you'll just hit a lower preboil volume (ETA assuming you keeping the mash thickness the same), I struggled with adding that to the question because it is the first thing people think of.

So maybe for clarity I should add, for a "defined preboil volume", but I don't think that matters for this end of the SG spectrum?

Not sure though!

 

[sibelman]

If, instead of sparging until 1.008, you sparge until you hit your desired pre-boil volume, then adjusting the quantity of malt is all you need to do to get the desired OG. You're apparently worried this could lead to astringency from over-sparging. I suppose there's some minimum malt quantity below which this becomes a concern, which maybe could be mitigated with water chemistry adjustment of some kind.

Sure, adding water to the boil would address the issue. I don't know if that's a common practice. I suppose I haven't confronted this because my lowest gravity brews are ordinary Pilsners with post-boil gravity in the low 40s.

 

[Uke733]

If, instead of sparging until 1.008, you sparge until you hit your desired pre-boil volume, then adjusting the quantity of malt is all you need to do to get the desired OG. You're apparently worried this could lead to astringency from over-sparging. I suppose there's some minimum malt quantity below which this becomes a concern, which maybe could be mitigated with water chemistry adjustment of some kind.

Sure, adding water to the boil would address the issue. I don't know if that's a common practice. I suppose I haven't confronted this because my lowest gravity brews are ordinary Pilsners with post-boil gravity in the low 40s.

Stopping sparging earlier will make it worse, everything you say is true at higher SGs.

I can't get below 1.040, and it isn't an efficiency issue either.

 

[mashdar]

There is no such thing as over sparging if your water won't raise the pH. sibelman is saying you go past 1.008.

 

[Uke733]

There is no such thing as over sparging if your water won't raise the pH. sibelman is saying you go past 1.008.

You are right I misunderstood, thank you, so you are proposing everyone goes past 1.008 on low SG beers?

ETA: Within the context of my original question

 

[sibelman]

Additional ideas on this can be found in this thread. Notably, @doug293cz says:

If the instantaneous run off gravity gets below about 1.010, the pH buffering capacity of the mash becomes very low, and the risk of extracting tannins increases. Tannin extraction can be prevented by adequately acidifying the sparge water, so that the pH in the MLT never goes above about 6.0.

Best wishes for your low-alcohol brewing, @Uke733.

 

[Uke733]

Additional ideas on this can be found in this thread. Notably, @doug293cz says:

If the instantaneous run off gravity gets below about 1.010, the pH buffering capacity of the mash becomes very low, and the risk of extracting tannins increases. Tannin extraction can be prevented by adequately acidifying the sparge water, so that the pH in the MLT never goes above about 6.0.

Best wishes for your low-alcohol brewing, @Uke733.

Thanks Sibelman, so if I understand you correctly you are saying everyone sparges past 1.008/1.010 when doing low SG beers.

ETA: Within the context of my original question