Author Topic: New to all grain a few ?'s  (Read 1959 times)

Online BrewBama

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Re: New to all grain a few ?'s
« Reply #30 on: October 07, 2015, 10:33:39 AM »
ANY size....I use it for 5.5, 8 and 10 gal. batches.  That's as big as I brew, but there's a 7 bbl. brewery near me who batch sparges and gets efficiency in the 90s.
How do you calculate efficiency?

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Yiou start with the theoretical potential extract from the grain....around 36 points per lb. gal. is average.  so 10 lb. of grain in 5 gal. would give you a theoretical max of (10*36)/5 or a 1.072 OG.  If you got a 1.065 OG, your efficiency would be 65/72 or about 90%.
Do those 36 points apply regardless of grain type? IOW you've taken into account some grains will only contribute color, complexity, and flavor?

that's his assumption but if you want to really nail it down you can usually find estimates for the potential of different grains.  36 is just the average.

for instance in my spreadsheet I have 2-row at 36, munich at 37, carared at 35, victory at 34, etc.
Got it. Thx
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Re: New to all grain a few ?'s
« Reply #31 on: October 07, 2015, 04:02:38 PM »
I was telling him not to try to "fly sparge" on a dry grain bed.  you seem to be comparing no sparge with batch sparging.  in general yes, batch would be better than no sparge when it comes to efficiency.

My point was that we were forced to spray the sparge liquor onto the dry grain bed, then run it off without stirring.
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Re: New to all grain a few ?'s
« Reply #32 on: October 07, 2015, 04:03:48 PM »
I've read that exposing the hot grain to air is bad & hence you need to keep the liquid above the grain, but I'm not sure if this is true or yet another brewing myth.

If that's the wrong way to do it, I've made 487 batches of bad beer and won some awards for it!

Denny, you are the reason I am all grain brewing.  Everybody else made it seem so complicated.  After listening to you on the Beersmith podcast I researched your methods, built a mashtun, and have at least 79% efficiency per batch.  Thank you so much.  I am brewing the best beer possible, having the most fun possible, and doing the least amount of work!

I love you, man!  ;)
Life begins at 60.....1.060, that is!

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Online denny

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Re: New to all grain a few ?'s
« Reply #33 on: October 07, 2015, 04:06:28 PM »
Do those 36 points apply regardless of grain type? IOW you've taken into account some grains will only contribute color, complexity, and flavor?

I've heard others say to expect 5 points per lb of grain. I guess that's the 70% I see all the recipes written for.

It's the average.  Some may be a bit higher, some a bit lower.  5  points per lb. does account for efficiency and that's what I use for a quick estimate.
Life begins at 60.....1.060, that is!

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Re: New to all grain a few ?'s
« Reply #34 on: October 07, 2015, 04:44:28 PM »
I was telling him not to try to "fly sparge" on a dry grain bed.  you seem to be comparing no sparge with batch sparging.  in general yes, batch would be better than no sparge when it comes to efficiency.

My point was that we were forced to spray the sparge liquor onto the dry grain bed, then run it off without stirring.

right, still better than not having that water touch the grain.  I would assume he has the option to stir the grain which should be better though.

Offline dilluh98

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Re: New to all grain a few ?'s
« Reply #35 on: October 07, 2015, 04:52:20 PM »
I use the following method (quoted from S. cerevisiae in an older post) for determining extraction rates. It's simply determining how many points (example: 1.050 is 50 points) you get out of one pound of grain mashed in one gallon of water. This works out to points per pound per gallon or (point x gal / lb) or PPG. I don't worry about what types of grains go into the recipe because generally most recipes are heavily weighted toward base malt anyway (you could go and get the weighted diastatic power of each individual grain in the recipe but it's a lot of extra work for not much increase in accuracy - the wiggle room on your batch to batch process is probably more than the increase in accuracy you'll get by doing it this way). Calculate the PPG for several batches and you'll notice it doesn't change much as long as your process is pretty much the same (if it does change drastically you might want to look at your notes to see if something went astray or maybe you got a bad crush from the LHBS). Then you can look at a recipe as a percentage and just say you want 6 gallons of 1.060 wort at the end of boil. Using your averaged PPG it is then trivial to determine the total grist weight you'll need to hit that target (6 gal. x 60 points / PPG = total lbs needed). Total grist weight can then be multiplied by the percentages of each grain in the recipe and you're done. See below for more detail.

Quote
flbrewer, if it helps, you can bypass efficiency percentages and work directly in points per pound per gallon.  I prefer to use extraction rates in points per pound per gallon because it is a directly applicable value.  Extraction efficiency is an indirect value that requires an additional weighted computation to be performed.

total_gravity_points = 6.25 * 60 (1.060 in gravity points) = 375

points_per_pound_per_gallon = total_gravity_points / grist_weight

points_per_pound_per_gallon = 375 / 16 = 23.44

What this value means in layman's terms is that the original recipe was formulated to achieve an extraction rate of 23.44 gravity points per pound of grain, that is, the extract from one pound grain dissolved in a one gallon solution has a specific gravity of 1.02344  That's a value that can be easily applied in one brew house. Working the other way yields:

original_gravity = points_per_pound_per_gallon * grist_weight / batch_volume / 1000  + 1.0

original_gravity = 23.44 * 16 / 6.25 / 1000 + 1.0 = 1.060

The way to determine one's brew house extraction rate in points per pound per gallon is to simply track the original gravity and total final boil volume minus the break and hops for each batch.  For each batch in the sample, calculate a batch extraction rate using the following formula:

batch_extraction_rate = original_gravity_in_points * batch_total_volume / grist_weight

I calculate this value when I take my original gravity reading.  After a few batches have been brewed, it's time to calculate an average batch extraction by summing the batch extraction rates and dividing by the number of batch extraction rates.

Batch Extraction Rates

Batch #1 - 28 points per pound per gallon
Batch #2 - 27 points per pound per gallon
Batch #3 - 29 points per pound per gallon
Batch #4 - 30 points per pound per gallon
Batch #5 - 29 points per pound per gallon

average_batch_extraction_rate = 28 + 27 + 29 + 30 + 29 / 5 = 28.6

Now, we can convert the recipe to our brew house by calculating a grist scaling factor.  Our extraction rate is higher than the original extraction rate; therefore, this value will be less than one.

grist_scaling_factor = 23.44 / 28.6 = 0.82

All we need to do from this point forward is to multiply every quantity in the grist by 0.88 to scale the grist to our brew house.  We do not need to adjust the hop bill because the bitterness unit to gravity unit ratio will remain the same.

While what I just wrote seems like a lot of work, what you will find over time is that these calculations become automatic, and you will no longer have to compute an average batch extraction rate because your extraction rates will converge within a close enough range that you can ball park it without actually performing the calculation.  When that happens, you will be able to look at a recipe for 6.25 gallons 1.060 wort, and think I need to use 60 / 28.6 = 2.1 pounds of malt per gallon to hit that gravity.  At that point, you will prefer to look at recipes as percentages, which is the way that professional brewers state recipes.  For example, we are making a bigger version of SNPA, which is often quoted as having a grist that is 95% 2-Row and 5% C60.

total_grist_weight = 2.1 * 6.25 = 13.125 pounds

pounds_of_2Row = 13.125 * 0.95 = ~12.5
pounds_of_C60 = 13.125 * 0.05 = ~0.65

As you have more than likely already ascertained, the values add up to more than 13.125 pounds.  I rounded to make measuring a little easier.