Several People have asked me about no-sparge mashing, what it is and how you
calculate a grain bill for a no-sparge mash. It's my hope the following text
will be of help in understanding the mechanics of no sparge brewing in general.
While I have conducted many no-sparge mashes (for those interested check out
My No-Sparge
Rig), if you are reading this article most likely you are new to
no-sparge mashing. As such, the article was written in reference to my first
attempt at no-sparging and what thought processes went into doing it. I hit
the numbers on the nose (well, real close) during my first run!
Part 1, What is a No Sparge Mash?
No-sparge mashing is simply collecting the first running from the mash tun as
opposed to sparging out the additional sugars. The benefits (while still being
debated) include a richer, maltier beer. The reasons for this seem to be the
fewer tannins leached from the mash due to the lack of sparging.
While no-sparging may produce a better beer, it is also less economical,
requiring from 1/3 to 1/2 additional grain in the mash grist. It is for this
reason alone that sparging came into existence; to increase the yield of the
grain and thereby reduce the cost of making beer.
'Pure' no-sparging is to simply take the first running when the mash is
complete. 'Batch' sparging is to add an additional infusion of water at
the end of the mash, but to sill not-sparge the mash in the traditional
'rinsing of the grains' fashion.
Part 2, Things You Need To Know
(Note that these formulas do not take into account the non-linearity of
extract potential at a specific gravity (such as ProMash does), but will get
you very, very close and are meant for fast hand calculations).
- The Dilution Formula (reference Ray Daniels, Designing Great Beers)
Most of the dilution/gravity calculations found in this write up are based on a
simple formula that states:
Beg Volume * Beg Gravity=End Volume * End Gravity
(The Gravity numbers are Gravity Points, i.e. 1.060 OG=60 gravity pts,
1.045=45 gravity pts.)
By algebraically re-arranging this formula, we can find any element in the
formula, as in:
Beg Volume=End Volume * End Gravity / Beg Gravity
Beg Gravity=End Volume * End Gravity / Beg Volume
End Gravity=Beg Volume * Beg Gravity / End Volume
End Volume=Beg Volume * Beg Gravity / End Gravity
It will serve you well in all your dilution/concentration calculations to have
this formula committed to memory.
- How many extra pounds of grain should I use for a No-Sparge batch?
Conventional wisdom says 1/3 more grist for the mash, and use the same qts/lbs
water ratio in the mash as you would with a normal sparged batch. However, this
figure is based on a perfect grain/water absorption rate of 0.10 gallons per
lbs. I have found that I absorb 0.12 gallons per lbs of grain, and your number
maybe different. (I have suspicion that the grind used in milling may have
an effect on the grain absorption ratio as well). Additionally, you'll need
to do some experimentation with the qts/lbs ration of the mash to determine
what you will actually get in runnings, and then do the math to figure if you
can achieve your desired pre-boil gravity by diluting that amount. If not, you
need to keep up-ing the grain amounts and/or tweaking the qts/lbs ratio until
you make the numbers work.
In my first no sparge session, I was lucky enough to hit the numbers almost on
the nose the first time. While my original recipe called for 14
lbs of grain, I increased the amount to 24 lbs based on
my calculations. You'll note that with my grain absorption figure I
needed more than 1/3 my original amount.
I highly recommend playing with the qts/lbs grain ratio in the stand-alone
Water Needed Calculator, and also keep tabs on your exact gallon per lbs grain
absorption rate as this is such a critical component. Once you start playing
with the numbers a bit you'll get a feel for it.
- How do I know what the gravity of the first runnings will be?
Now, determining the gravity of these runnings is a tricky matter, and I'm not
sure how to automate this at the time, but the recent Brewing Techniques
article (July/August 1998, Vol 6, No. 4, Louis Bonham) on no-sparging
states that at a 0.80 qts/lbs ratio runnings will be about 1.121
OG and at a 1.25 qts/lbs ratio runnings would be at about
1.080.
In my first attempt at no sparging, I was using a 1.15 qts/lbs ration, I
estimated my runnings would be 4.0 gallons of 1.086 OG first wort
runnings. What I actually achieved was 4.0 gallons of 1.083
runnings, and I actually got 4.4 gallons when the grain bed ran
dry (calculations were almost on the nose, but off just a hair). I actually
needed the tiny extra amount to achieve my desired final gravity.
So again, this is a matter of knowing your system and the variables, tooling
around with the qts/lbs mash ratio, grain absorption rate, desired OG, etc.
Part 3, How I Calculated My 1'st No Sparge Batch
Now, when I did my first batch, I broke the problem down to 5 distinct
questions, which if I could find the answer to each I should successfully be
able to brew a no-sparge batch to the numbers. So, here was my train of
thought, and how I achieved my results. Remember, these were questions I was
asking myself and as such this next section is written in the first person:
- How many gallons do I want at the end of the boil and at what
gravity?
For this recipe I want 6 Gallons at 1.060 OG at the end of the boil.
- How many gallons of preboil wort do I need to reach the desired gravity
of 1.060 when the wort is boiled to 6 gallons?
Using the Water Needed calculator I see that with my evaporation rate of
20% per hour, and a boil time of 75 minutes, I will
need to start with 8 gallons of water to boil to 6.
- What will the gravity of the pre-boiled wort need to be?
Here again I use the dilution formula to find the beginning gravity:
Beg Gravity=(End Volume * End Gravity ) / Beg Volume
which breaks down to:
Beg Gravity=(6 * 60) / 8
which is 45 gravity pts or 1.045 OG. Thus, I need to start with
8 gallons of pre-boil wort at 1.045 to get 6 gallons at
1.060 after the boil.
- How will I know the gravity and amount of first running I will collect
from the mash?
In my system I have my water absorption rate set to 0.12 Gallons per 1
LBSgrain. (set this rate in the System Settings of ProMash). I
had also determined I was going to use a 1.15 qts/lbs ratio in my
mash. The mash totalled 24 LBS and 6.9 gallons of mash water.
Using the Water Needed stand-alone calculator, I determined that with the grain
absorption rate and qts/lbs ration used I would collect 4.1
gallons of first wort runnings.
(I should also note here that I used the Water Needed calculator extensively
to fool with the ratio's and determine what amounts I would collect, estimating
the amount of gravity, which in turn backtracked to how much I actually needed
in the grain bill. I did this a few times to get the numbers to what I thought
would actually work. I suggest you experiment around a bit here!)
Since I was using a 1.15 qts/lbs ration, I estimated my runnings would be
4.1 gal of 1.086 OG first wort runnings. What I actually achieved was
4.0 gallons of 1.083 runnings, and I actually got 4.4
gallons when the grain bed ran dry (calculations were almost on the
nose!). I actually needed the tiny extra amount to achieve my desired final
gravity.
- How much water will I dilute with to achieve the correct gravity at the
end of the boil?
Next, remembering that I wanted 8 gallons of pre-boil wort at a gravity
of 1.045, I again used the dilution formula to determine what I needed
to add to the first runnings. I did this both before the actual brew
session and immediately after collecting first runnings. I had
initially estimated a 1.086 OG from the running and was planning on only
collecting4.0 gallons. Instead though my runnings where 1.084
(determined fast using the Hydrometer correction calculator), so I had
to quickly recalculate how much I actually needed to runoff, which was 4.3
gallons. So again, re-arranging the Dilution formula properly:
End Volume=(Beg Volume * Beg Gravity) / End Gravity
Which in my case was:
End Volume=(4.3 gal water * 84 gravity pts) / 45 gravity point)
which equals 8 gallons, my pre-boil target, so I knew I was OK.
Knowing these numbers would work, all that was left was to subtract my
4.3 gallons of collected running from my 8 gallons pre-boil target to
see I needed to add 3.7 gallons of dilution water to the first
runnings.
I boiled down to exactly 6 gallons at 1.060 OG, my exact target!
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