Some Rookie Mash Questions

[Mikelush78]

I have just completed my 3rd all grain batch and got an efficiency of 66%. I know that is low for most but that is my highest so far! Want to get that better so I will explain what I did and you can point out the errors in my way!

I bought a new Barley Crusher and set the gap to .030 (had issues with the crusher at the store near me so bought my own)

The crush looked good to me (mind you I am still new)

The Mash is where I think I have some room to go. I put 3.5 gallons of 175 degree water in my cooler and let it warm the cooler for 10 min.

Opened the cooler and waited till the water got to 166 and then poured my grains in slowly while stirring so as to not get clumps.

Reached my target of 153 degrees and held it there for almost the entire 60 min, went down to 152 for the last 5 min or so.

Added 1.25 gallons of 175 degree water to the mash and stirred is in to raise temp for sugars to exit easier.

I then had my run off in a pitcher a few times to get the Wort clear.

This is where my error was I believe, I drained the cooler fast (opened up the valve all the way)

I have read conflicting things here where this does not affect the mash and some say you need to drain the mash slowly….?????

Then I added 2.75 gallons of 175 degree water to the mash tun, stirred it up and then drained it after getting Wort clear from pitcher again…

I used 10.75 #’s of grain and got a total of 1.050 after the boil.

Another dumb question is:
After the mash is there a way to figure out Efficiency then? Or do you have to check after the Boil? Just seems like if you knew after the Mash you can adjust things to help fix for problems better if you knew before the boil…

 

[Bluelinebrewer]

One thing that really helped raise my efficiency was double batch sparging. Ill figure out what my total sparge volume should be, then divide that by 2. Each of those sparges are put in at 185℉. I went from low 60s to mid 70s just by changing this.

 

[johngaltsmotor]

Did you stir the mash during the 60 minutes? I typically stir every 15 min or so.
For the mashout, you should use boiling water and calculate the volume needed to bring the mash up to your target temp. At 175F additional water temp you likely didn't heat the mash up much. Then use 170F for the sparge water.
I've gotten 85% with a fast drain before so it's not impossible, but common results are that the slower drain results in higher efficiency.
Instead of worrying about efficiency after the mash I simply worry about gravity. recipe OG * post-boil volume / pre-boil volume = desired Mashout gravity If your measured mash-out gravity is too low you can add LME/DME to compensate, if too high dilute with water.

 

[Bluelinebrewer]

Did you stir the mash during the 60 minutes? I typically stir every 15 min or so.

+1 on this as well!

 

[Mikelush78]

I stirred the mash every 15 min on my first all grain batch and lost about 4 or 5 degrees total, so I read a lot of people say don't stir it so this time I did not stir.

ok I understand now I want to get the mash up to 175 by adding the boiling water... This also makes a lot of sense and will do that next time.

Thanks for the input so far guys!

 

[Mikelush78]

I also Like the double batch sparge, might do that next time also.. makes sense to me... cant hurt

 

[kh54s10]

From what I have read some think that you need to drain slowly and others do not. I have not seen any difference. Some also say that double batch sparging will help and others don't. I always do a double sparge but not for efficiency. I do it because it is easier to end up with the proper volume that way. The second sparge is the amount to get to preboil volume.

I have also read that the temperature of the sparge is not a concern either as long as it is not boiling the grain. Just water to wash out the remaining sugars. I always use 168 degrees though.

I am still chasing efficiency. I will get 2-5 batches dead on then one that is off, either high or low on OG. I am still trying to figure out why.

I guess you need to figure out what works best in your setup.

 

[Iamslow]

One thing that really helped raise my efficiency was double batch sparging. Ill figure out what my total sparge volume should be, then divide that by 2. Each of those sparges are put in at 185℉. I went from low 60s to mid 70s just by changing this.

+1 for the equal double batch sparge. For me it's also easier to nail your pre-boil volumes with this method.

I also prefer a slower runoff, but like another poster mentioned it really is all about nailing your pre-boil gravity. So if my readings are on and I know how much sugar I have then I will open it up to speed up the process.

 

[woozy]

After the mash is there a way to figure out Efficiency then? Or do you have to check after the Boil?

Can't help you with the mash but can help you with this.

1) Pre-boil volume * pre-boil gravity points = post-boil volume * post-poil gravity = total amount of sugar in you wort (before or after boil doesn't matter because the sugar remains and doesn't boil away; the gravity will become higher because the water will become less).

2) max PPG yield * lbs. of grain = maximum amount of potential sugar (This is the total amount of potential sugar to be extracted from the grain.)

ergo

3) efficiency = extracted sugar/total sugar = Pre-boil volume * pre-boil gravity points/max PPG yield * lbs. of grain

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Explanation and details:

Take a specific gravity reading of your post-mash pre-boil runnings. Let's say, that it is 1.038. Drop the 1 and multiply by 1000 to get 38 points.

Measure the volume pre-boil. Let's say it is 7.5 gallons. Multiply that gravity points by the volume. 7.5 * 38 = 285. This represents a specific amount of total sugar that is in your liquid. Each gallon had 38 of these units. (Each unit is enough to raise 1 gallon 1 gravity point so a gravity of 1.038 means that each gallon has 38 of these units.) You had 7.5 gallons. So you have a total of 285 units of sugar.

[To be honest, I'm not really sure what to call these units. Each unit (by my reckoning) is 1/46 of a lbs of sugar. I call them "gallon-points" but I've seen them called "gravity units". They represent the amount of sugar, that when mixed with water to make 1 gallon of liquid, will have 1 gravity point, or a specific gravity of 1.001. 1 pound of sugar mixed with water to make 1 gallon of liquid has a specific gravity of 1.046 so 1/46 of a pound in a gallon has a specific gravity of 1.001 or 1 gravity point. But I digress.]

Now calculate the maximum yield of your grain bill. The rule of thumb is that grain is 37 PPG (points per pound per gallon). Some grain will be 35 and some will be 38 but for a rough estimate, if we assume 37 we will be accurate enough for a rough effeciency percentage. But there are tables of specific grains and you can calculate this precisely if you want to.

37 PPG. This means that if you converted and extracted *every* single bit of sugar in a pound of grain you have 37 of the above units of sugar.

Multiple the max. yield by the number of pounds. Let's say you used 11 lbs. of grain. 11 * 37 = 407. That means 11 pounds of grain has 407 potential units of sugar.

[edit: *if* you want to be precise and say you have 5 lbs of grain with 38 PPG and 6 lbs of a grain with 35 PPG you'd just to them separately and add the total up. 5 lbs @ 38PPG is 190 units and 6 lbs @35PPG is 210; 190 + 210 = 400 maximum potential units. But the idea is the same, right? ]

Divide the two numbers. 11 lbs of grain has 407 potential units of sugar. You managed to extract 285 of them so your efficiency is 285/407 = 70%.

What happens now? Well, you boil away the sugar remains. You end up with 5 gallons of wort but this wort still has 285 units of sugar in it. That's 57 units per gallon. That's enough for a gallon of liquid to have 57 gravity points so your post-boil original gravity will be 1.057.

Note:
Pre-boil volume * pre-boil gravity = 7.5 gallons * 38 points = 285 gravity units
post-boil volume * post-poil gravity = 5 gallons * 57 points = 285 gravity units.

And that's how you figure out efficiency.

 

[Mikelush78]

woozy, your the man!

Thanks for that info!

 

[LovesIPA]

[To be honest, I'm not really sure what to call these units.

According to Ray Daniels' "Designing Great Beers" they're called gravity units aka GU.

Great post though.

 

[woozy]

According to Ray Daniels' "Designing Great Beers" they're called gravity units aka GU.

Great post though.

I *just* read that yesterday. I like calling them gravity units so I will from now on. Before I heard them referred to as "points" which... I didn't like because it's misleading. The *real* gravity points refer to a *ratio* of weight. A solution has 57 *points* means the gravity is 1.057. An ounce of this solution will have so much total sugar but a gallon or a liter will have another, because, d'uh, a gallon, a liter, and an ounce are all different sizes. These "units" which are measured by multiplying volume in gallons by points, represent a *total* absolute amount of sugar. Just like a gallon (or a liter, or an ounce) represents a total absolute volume of liquid.

Technically "gallon-points" is accurate; They respresent the amount of sugar in a gallon with a specific point measure. And if you do the math (5 gallons * 38 points = 190 gallon-points and 37 points/(lbs/gallon) * 11 pounds = 407 gallon-points) the units "fall into place". But this is really awkward though. And unless one is a physicist or an engineer such concepts as a "gallon-point" or a "foot-lb" or "square dollar"[*] can really boggle one's intuition.

When I read "gravity unit" yesterday it seemed perfect. It's the amount sugar that will cause a gallon of liquid to read 1 gravity point. Clear, precise, unambiguous and intuitively easy to grasp.

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[*] What the eff is a square dollar, you ask. Well, here's a puzzle you can use to stump your friendly neighborhood eighth-grader:

Take a dollar. That's 100 cents. 1 dollar * 1 dollar is 1 dollar. Okay, but 100 cents * 100 cents is 1,000 cents and 1,000 cents is = 10 dollars. So 1 dollar = 10 dollars. What the heck?

 

[winvarin]

Another proponent here for the double batch sparge. I have moved to a pump driven system so I am fly sparging these days. But when I was batch sparging, calculating my absorption rate, then dividing my water so that I could do first runnings, then 2 batch sparges, did a lot for my efficiency.