Importance of mash water volume?

[psujeeperman02]

I loved making the switch to AG brewing. I still cannot wrap my mind around the volume of water needed for mash and striking...as well as what issues there'd be if I didn't use the correct amount.

For example, Im brewing an IPA this weekend with 12.5 lbs of grain.
The recipe that I found says to use 5 gal of water mashing.

However, If I run an online calculator, or even punch the recipe into beersmith, they tell me I only need just shy of 4 gallons.

Is one gallon less in the mash going to make a difference? And why does online calculators say I need 4 gals and the recipe calls for 5 gals?

Strike water is a bit easier because you need to wash the grains and get your volume up to pre-boil levels.

 

[GoeHaarden]

I usually stick to 1.25-1.5qt/lb of grain, so really either one of your amounts would work. If you have a lot of stuck mashes with your setup then I would lean towards a thinner mash, using more water.

Recipes usually make generalizations that should be successful for everyone...they're not specific to anyone's particular setup.

Check out this xbmt on grist ratios
http://brulosophy.com/2016/02/15/the-mash-standard-vs-thin-liquor-to-grist-ratio-exbeeriment-results/

 

[pricelessbrewing]

Mash thickness has little impact, apart from water chemistry, lauter efficiency, and avoiding stuck sparges if it's too thin or thick (depending on your equipment).

I always recommend running your own water and temperature calculations and tailor it to suit your equipment and preferences.

Beersmith and (most) calculators do not *tell* you anything, they calculate outputs based on user inputs.

Some do not support certain processes, and many have default process assumptions (mine included), but we do not for instance say, "sorry you have to use 5 gallons of strike and 3 gallons of sparge". If you want to adjust your strike volume (which determines mash thickness), you should be able to pull the levers of "mash thickness, strike volume, or sparge volume."

 

[Lefou]

Some beer styles are more forgiving than others, some more narrow in the recipe requirements. Not everyone is going to have the same efficiency, boil-off rate, or equipment. I've even noticed weather and seasons have an effect and influences my results.
My typical mash thickness runs a bit thinner at 1.5qt of water per pound of grain to account for the odd variables I tend to run into on brew days. Seems to work and suits my preferences, so I stick with it.

 

[TheMadKing]

I loved making the switch to AG brewing. I still cannot wrap my mind around the volume of water needed for mash and striking...as well as what issues there'd be if I didn't use the correct amount.

For example, Im brewing an IPA this weekend with 12.5 lbs of grain.
The recipe that I found says to use 5 gal of water mashing.

However, If I run an online calculator, or even punch the recipe into beersmith, they tell me I only need just shy of 4 gallons.

Is one gallon less in the mash going to make a difference? And why does online calculators say I need 4 gals and the recipe calls for 5 gals?

Strike water is a bit easier because you need to wash the grains and get your volume up to pre-boil levels.

So just clearing up some terminology:

Strike water is the water you mash with. Strike water volume = mash water volume

Your preboil volume = (Strike water + sparge water) - (grain absorption+MLT loss)

So if you do not use enough strike water you can undershoot your preboil volume, and have to add top-up water, or sparge more (which can result in off flavors).

If you're asking if mash thickness changes the flavor, then no not really, as long as you have enough mash water for conversion to take place, and don't over-sparge. You can make exactly the same beer using 4 gallons of strike water or 7 gallons of strike water. It will just change how much you sparge.

 

[65C]

I have no idea what I'm doing - but here is where I am currently

I make 23L (5 gallon) batches usually with around 5KG of grain - I do 2.5L per 1KG of grain for the strike water

so that is 12.5L for a 5KG batch - I'll put some lactic acid in that to get it down to 5.2PH as the water is hard here - which goes in for an hour at 77C and gets grain to 68C for the mash

I'll run that off and get a lot less than 12.5L out after an hour or so

then I'll do two sparges of 11L without any lactic acid - so total water used is 34.5L - from that I'll get 29L for boil - I'll lose 4L in the boil and 2L in the hops after - which gets me down to 23L in the carboy at the end

I've no idea if this is right - I like low tech brewing so don't use a hydrometer - beer comes out good but probably on the high alcohol side - so I'm dropping the grain back at the moment

not sure if this helps or confuses you more

 

[Sadu]

Yeah that seems about right. I'll typically use 33-34L total for a 23L batch (in the fermentor). Tonight's brew I used 17L of strike water for 5.7kg of grain, so a bit thinner than yours but in the same ball park. I like to mash a bit thinner since I recirculate and thick mash equals stuck pump.

 

[pvpeacock]

I used to worry about mash thickness, but eventually reached the point where I just mash in with 5 gallons every time for a 5 gallon batch regardless of the amount of grain. I then batch sparge with enough water to make up my desired pre-boil volume. I have not noticed any difference in the end product, and it simplifies the brew day.

 

[GoeHaarden]

I like low tech brewing so don't use a hydrometer

Awesome! I commend you!