# Length of mash



## Milhouse (7/12/18)

Most of my brews I use a 60 minute single infusion mash without a mash out. Today I let my mash go to 75 mins as I was busy at the time.

I missed my estimated pre boil gravity by 1 point which I consider a win as my last couple of brews have been several points under my estimated pre boil gravity. 

Hence I am thinking of mashing a bit longer for all my brews but I am wondering if this can/will have any other effects on my beer?


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## smertin (7/12/18)

Milhouse said:


> Most of my brews I use a 60 minute single infusion mash without a mash out. Today I let my mash go to 75 mins as I was busy at the time.
> 
> I missed my estimated pre boil gravity by 1 point which I consider a win as my last couple of brews have been several points under my estimated pre boil gravity.
> 
> Hence I am thinking of mashing a bit longer for all my brews but I am wondering if this can/will have any other effects on my beer?


I reckon you will be ok with a longer mash. I think the longer you make it the more attuention you are likely to get. May just finish a little lower gravity / higher ABV than you were aiming for (nothing wrong with that though  )
From my understanding the purpose of a mash out is to lock the sugars in place, seems to be more of a feature to add to your brews for easily reproducing of a recipe.


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## philrob (7/12/18)

As you said, a longer mash will allow the enzymes to work for longer and should give you better Apparent Attenuation. 
A mashout is also done to improve your run off and lauter by making the wort more liquid.


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## MHB (7/12/18)

God I wish it were that simple!
Although temperature is the biggest factor. But (always a But in brewing) time, pH, salts (especially Ca and Zn), mash thickness (L:G), your crush, your strike temperature... and more. Will all affect what happens.
The main two reasons to mash out are to end most enzyme activity (that doesn't just affect your attenuation) and to make the wort more fluid (to drain faster), hotter liquor (water) also helps to extract the residual goods from the grain, the hotter the better until you start to extract too much tannin at around 80oC.

It's generally a mistake to expect a simple answer to most brewing questions.
Just increasing your mash time will have a limited effect, at or near their peak activity temperatures, enzymes have a very finite life span, the benefit for say doubling the mash time isn't any near twice the activity, closer to the inverse for the second hour really.
An hour is usually more than enough, an hour and a half will get you some small gains but from then on its probably not worth the time. Go too far (see discussions on overnight mashing) and some very undesirable effect can (will) start to show up. Including the possibility of over attenuation, poor head retention and even the dreaded tannins.
Just remember we want things in our beer besides alcohol, or we would all be drinking vodka, too much attenuation isn't a goal its a problem.

A planed mash schedule is designed to give high efficiency, to produce predictable and repeatable beer with the right balance of both fermentable and residual products (not just sugars). If you have a recipe that produces the beer you want, don't screw around with the mash profile lightly.
Mark


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## garage_life (7/12/18)

MHB said:


> God I wish it were that simple!
> Although temperature is the biggest factor. But (always a But in brewing) time, pH, salts (especially Ca and Zn), mash thickness (L:G), your crush, your strike temperature... and more. Will all affect what happens.
> The main two reasons to mash out are to end most enzyme activity (that doesn't just affect your attenuation) and to make the wort more fluid (to drain faster), hotter liquor (water) also helps to extract the residual goods from the grain, the hotter the better until you start to extract too much tannin at around 80oC.
> 
> ...


Don't remind me! [emoji37]


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## Schikitar (7/12/18)

Just like I tell my wife, it's not about the length, it's what you do with it that really counts..


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## razz (8/12/18)

Schikitar said:


> Just like I tell my wife, it's not about the length, it's what you do with it that really counts..


I told her the same thing. My wife, not yours!


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## Milhouse (8/12/18)

MHB said:


> God I wish it were that simple!
> Although temperature is the biggest factor. But (always a But in brewing) time, pH, salts (especially Ca and Zn), mash thickness (L:G), your crush, your strike temperature... and more. Will all affect what happens.
> The main two reasons to mash out are to end most enzyme activity (that doesn't just affect your attenuation) and to make the wort more fluid (to drain faster), hotter liquor (water) also helps to extract the residual goods from the grain, the hotter the better until you start to extract too much tannin at around 80oC.
> 
> ...



Thanks Mark,

I guess what I was really asking was are there any potential ill effects from mashing a bit longer and it seems from your and others responses for the extra 15-30 mins it seems the answer is no.

However I am still baffled that I am getting mixed results when it comes to efficiency. I have had a bit of a pore over my notes and it seems I am getting poorer efficiency with certain recipes over others.

I don't play with my water apart from some met to remove chlorine. I cant seem to get a reliable water report and don't have the money to invest in a RO setup currently. I also don't measure or adjust mash PH as I dont have a PH meter and have heard PH papers are useless. I usually use some dark crystal and/or roasted barley so figured that would drag down PH enough. However after some playing with Brewfather my caculated PH is usually in the 5.5x range which whilst isn't in the ideal range isnt far off.

So i guess at this stage although there are a couple of unknowns where would you think my efforts would be best concentrated:
-Finding out and adjusting water chemisty
-Measuring and adjusting mash PH
-Using a step mash
-Mashing a bit lower - I usually use recipes out of "Brewing Classic Styles" and most are mashed at 67-68 Deg C

On a separate note I have recently started using a refractometer and I am thrilled with its ease of use and significantly smaller sample size. I have been having issues with my pre boil gravity reading the same or higher than my post boil gravity. I always check my post boil gravity with a hydrometer as well and it always concurs with the refractometer reading. The last couple of batches I have mixed the wot really well before drawing off a sample to eliminate the possibility of a particularly concentrated bit of wort. The only other thing I can think of of temperature. My current method is to draw off a small amount, ~20ml, into a cup and leave it for a few minutes. Then I draw some into a pipette, invert and run the bulb under cold water to drop the temperature some more. Any suggestions what the problem might be?


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## Milhouse (8/12/18)

I just realised I missed the point on mash thickness. I ussually use 20l of water to around 6kg of grain. Is this too thin? I brew in a robobrew and find due to the dead space under the malt pipe if I use less water the amount exposed isnt enough to easily mix the grain.


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## altone (8/12/18)

Milhouse said:


> I just realised I missed the point on mash thickness. I ussually use 20l of water to around 6kg of grain. Is this too thin? I brew in a robobrew and find due to the dead space under the malt pipe if I use less water the amount exposed isnt enough to easily mix the grain.



I usually do 22l with about 5Kg of grain in the Guten 
Info here suggests ratios of up to 7:1 are fine but too thick a mash may cause problems.
https://aussiehomebrewer.com/threads/mash-thickness-and-efficiency.79839/


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## Milhouse (9/12/18)

Yeah I didn't think this was the problem as it is pretty constant and has successful.


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## MHB (9/12/18)

No real problem with mashing a bit longer, try it and see if it helps.
As for your other options, I'd wind it back a bit and start at the real basics, bit of a check list: -
Is the milling consistent and effective, I've seen some shocking crushes from both home brew shops and home brewers.
Temperature really is king, have you got a good quality glass laboratory thermometer to use as a reference? These aren't expensive (~$20).
pH really shouldn't be all that big an issue, if you ask around your local brewing community and take a long hard look at your local water supply, you should have a fair idea what to add salts wise, if in doubt add 100ppm of Ca in an appropriate form (to taste), maybe a little acid (I use Lactic) or acidulated malt
This one might surprise a few people, if you want high efficiency look at your sparge. In a modern brewhouse sparging can take from 90 to 240 minutes, that's in a really well designed high speed lauter, a lot of home brewers think 30 minutes is being really patient.

Mash thickness is interesting, thick mashes favour the activity of the enzymes that break up Protein and other structural parts like Glucan, thinner mashes favour Amylase activity, so a thick mash is good for high adjunct, less well modified malt and for beers with a pronounced malty bias (think big Pommy beers) thinner mashes are better for lighter more delicate beers like Lagers.
This ties in with L:G, the more water you mash in with the lower the OG of the first runnings will be. The less is left in the grist to extract during sparging. There is an equation that describes this pretty exactly
oP of first runnings = CGAI/L:G+CGAI
oP Plato, the alternate way to measure SG is %WW sugar in solution
CGAI is the potential of your malt in the form of Coarse Grind As Is (so the malt you are using including its moisture)
To get from oP to SG=(4*oP)/1000+1 is a pretty fair approximation (good to 1.0001)

If we assume that the CGAI is about 75% (0.75in equations) which is pretty typical for a modern good quality base malt and it takes at least a L:G of at least 2:1 to cover the malt in water - well easier in excel





If you want to get creative you can work out your efficiency, the mass of extract left in the malt, even the best amount of sparge water to strike water, how long to boil (given a known boil off rate) and a bunch of other bits and bobs.
At a small (home brewing) scale it probably isn't worth getting too excited, just use a bit more malt, don't over sparge and follow a sensible mash regime.
Mark


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## Ben Davies (9/12/18)

Check out www.Braukaiser.com he also has mash on experiment I'm sure mash length and more really informative if your into the geeky side of brewing and why we do certain things.
Most conversion I hear happens in first 15 minutes of mash I'm expecting beta Amalyse works slower and is responsible for the further break down of sugars in the extended mash. I rutinely go over 60 minutes in mash usually rest 40mins at 62-3 step to 68 or higher for 30 then spare 75c. I used to mash out but really what's the point the boil will halt them enzymes.


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## Milhouse (9/12/18)

MHB said:


> Is the milling consistent and effective, I've seen some shocking crushes from both home brew shops and home brewers.



I believe so, I almost always buy my grain from Hoppy Days in Brisbane who are reputable. The grain crush always appears consistent with no tearing of the husk.



MHB said:


> Temperature really is king, have you got a good quality glass laboratory thermometer to use as a reference? These aren't expensive (~$20).



I use a digital kitchen thermometer which I beleive to be accurate, I have verified it reads at 0C in an ice slurry and 100C in boiling water (at sea level). However I think I will get a good lab one as you suggest to eliminate that variable.

However as I think through my process there is a possible issue with temperature. I usually heat to only a couple of degrees over my target temperature as if i go any higher I overshoot my target mash temperature. I suspect the stainless holds heat well. 

When I dough in the top of the mash is a few degrees cooler and I start recirculating fairly quickly evening the temperature. Perhaps the small drop for 5-10 mins is causing an issue and I would be better off with a higher strike temp and letting it come back down to target temp?



MHB said:


> pH really shouldn't be all that big an issue, if you ask around your local brewing community and take a long hard look at your local water supply, you should have a fair idea what to add salts wise, if in doubt add 100ppm of Ca in an appropriate form (to taste), maybe a little acid (I use Lactic) or acidulated malt



I have been thinking for a little while that playing with my water chemistry is probably the next step in my brewing so this has given me the final impetus to go ahead and do it.

When you say add 100ppm of Ca wouldn't the anion make a huge difference, in fact probably more so? Or is that what you meant by "in the appropriate form"?

What is the reasoning behind the lactic acid, just to ensure the pH is low enough? How much are we talking here? 



MHB said:


> This one might surprise a few people, if you want high efficiency look at your sparge. In a modern brewhouse sparging can take from 90 to 240 minutes, that's in a really well designed high speed lauter, a lot of home brewers think 30 minutes is being really patient.



As i use a robobrew i basically lift out the grains and let them drain (more or less like BIAB), adding the sparge water to the top. As such I don't really have control over the speed of the sparge. This come back to the milling i guess. I have found it drains quite quickly, sparging about 14l in about 15 mins. I am tempted to have it crushed finer and see how that goes.

What does concern me is there are a few changes here and I don't want to changing everything at once and not know specifically what is effective and what is not, likewise I might have some adverse effects and not know what specifically has caused it. Any suggestions on what would be the best thing to start with? I am thinking either water chemistry as it seems about time and something i should look into anyway.


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## Milhouse (9/12/18)

Ben Davies said:


> Check out www.Braukaiser.com he also has mash on experiment I'm sure mash length and more really informative if your into the geeky side of brewing and why we do certain things.
> Most conversion I hear happens in first 15 minutes of mash I'm expecting beta Amalyse works slower and is responsible for the further break down of sugars in the extended mash. I rutinely go over 60 minutes in mash usually rest 40mins at 62-3 step to 68 or higher for 30 then spare 75c. I used to mash out but really what's the point the boil will halt them enzymes.



This is interesting, I had in the back of my head that most of the conversion happens early on hence wasn't sure how effective a longer mash would be. I have used a step mash recently in a dry stout so I have been considering a step mash for my other beers and seeing if it helps. As per my reply to MHB above i think I will play with my water chemistry first. I am not really trying to maximise efficiency, more to work out why my efficiency is inconsistent and make it more consistent.


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## wide eyed and legless (9/12/18)

The modified grains do not require a step mash, a good book to read is Mastering Homebrew Randy Mosher, in the book he states you could do more harm than good step mashing modified grains.
Here is a BYO link to step mashing. https://byo.com/article/the-science-of-step-mashing/


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## MHB (9/12/18)

Lots of questions and I'm still a little hung over - it looks like you have the basics covered. I would recommend a good glass thermometer, with bi-metallic (those dial things) and electronic thermometers (unless very high end) you are only ever guessing.

On lactic acid, a couple of reasons, one is that if you spill some on your self it wont do much harm, another is that 90% or so of the acidity in pale malt is from lactic acid bacteria on the malt, so you are only adding a little more of something that is already there.
Slightly more complex is the way Ca and Lactic acid, look at Ca-Lactate as that is what is formed if you have any Bi/Carbonate in your water, they form a really powerful buffer. Which at mash concentrations is close to where we want it. Anyone with a strong background in chemistry should have a look at the KSP's.

Think I'll go and get my head down for a couple of hours, I always enjoy the IBC Xmas party, but when the beer starts at 5% and works it way up to around 12%, it takes a toll on my aging body....
Mark


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## Mya (10/12/18)

MHB said:


> This one might surprise a few people, if you want high efficiency look at your sparge. In a modern brewhouse sparging can take from 90 to 240 minutes, that's in a really well designed high speed lauter, a lot of home brewers think 30 minutes is being really patient.
> ...
> don't over sparge



Hi Mark, I'm confused by the two above statements, can you please elaborate?


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## MHB (10/12/18)

Volume not time. the right volume, at the right pH and slow sparging gives higher efficiency.
Going fast leaves too much extract behind.
Too much water, too hot or too basic (alkaline) will all extract tannins.


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