Author Topic: poor all grain efficiency, don't know why  (Read 13519 times)

Offline melferburque

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Re: poor all grain efficiency, don't know why
« Reply #30 on: January 02, 2012, 09:49:04 PM »
wow, I wasn't aware I needed to drop the temp down to test ph.  they would have been taken at 150 and 170 degrees.

Offline euge

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Re: poor all grain efficiency, don't know why
« Reply #31 on: January 02, 2012, 09:52:30 PM »
wow, I wasn't aware I needed to drop the temp down to test ph.  they would have been taken at 150 and 170 degrees.

Room temp.
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Offline bluesman

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Re: poor all grain efficiency, don't know why
« Reply #32 on: January 02, 2012, 09:57:21 PM »
It's highly recommended to measure your mash pH at R.T.
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Offline jeffy

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Re: poor all grain efficiency, don't know why
« Reply #33 on: January 03, 2012, 04:16:11 AM »
It's highly recommended to measure your mash pH at R.T.
As a matter of fact you can watch the pH increase as the sample cools just 10 degrees, say from 80 to 70F it may move from 5.0 to 5.2.   Plus it's not so good for the life of the probe if you are using a meter (and not paper strips) to plunge it into hot liquid.
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Offline malzig

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Re: poor all grain efficiency, don't know why
« Reply #34 on: January 03, 2012, 04:25:30 AM »
If you are using the ColorpHast pH strips, the pH reading seems to be approximately the same at RT and mash temp, but they read ~0.3 pH points low.

Offline melferburque

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Re: poor all grain efficiency, don't know why
« Reply #35 on: January 03, 2012, 09:27:07 AM »
If you are using the ColorpHast pH strips, the pH reading seems to be approximately the same at RT and mash temp, but they read ~0.3 pH points low.

I am using the strips, so that may explain why my pH showed so low.  seems odd tho, why am I checking the pH at room temp, when the mash itself is at 150 or 170 degrees?  does it just not read accurately at that high a temp?

Online morticaixavier

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Re: poor all grain efficiency, don't know why
« Reply #36 on: January 03, 2012, 09:31:10 AM »
If you are using the ColorpHast pH strips, the pH reading seems to be approximately the same at RT and mash temp, but they read ~0.3 pH points low.

I am using the strips, so that may explain why my pH showed so low.  seems odd tho, why am I checking the pH at room temp, when the mash itself is at 150 or 170 degrees?  does it just not read accurately at that high a temp?

The pH doesn't change with temp just the reading. at least that is how I understand it. thw quoted 5.2 ideal pH is a reading at room temp. so that may mean a reading of 5.0 at mash temp but I am not sure that it is linear.
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Re: poor all grain efficiency, don't know why
« Reply #37 on: January 03, 2012, 09:49:26 AM »
The pH doesn't change with temp just the reading. at least that is how I understand it. thw quoted 5.2 ideal pH is a reading at room temp. so that may mean a reading of 5.0 at mash temp but I am not sure that it is linear.

No, the actual pH also changes with temperature, and it goes the other way. 5.2 pH at mash temp is ~5.5 pH at room temp. It's more or less linear when you're talking about a variation that small.

The reasons for measuring pH at room temperature are; first, that high temperatures are rough on pH probes; second, that there will be slight variations in the temperature dependence for different solutions; and third, that you need to have a standard in order to be able to share data, and 20°C is convenient for most people.
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Online morticaixavier

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Re: poor all grain efficiency, don't know why
« Reply #38 on: January 03, 2012, 10:42:14 AM »
The pH doesn't change with temp just the reading. at least that is how I understand it. thw quoted 5.2 ideal pH is a reading at room temp. so that may mean a reading of 5.0 at mash temp but I am not sure that it is linear.

No, the actual pH also changes with temperature, and it goes the other way. 5.2 pH at mash temp is ~5.5 pH at room temp. It's more or less linear when you're talking about a variation that small.

The reasons for measuring pH at room temperature are; first, that high temperatures are rough on pH probes; second, that there will be slight variations in the temperature dependence for different solutions; and third, that you need to have a standard in order to be able to share data, and 20°C is convenient for most people.

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Offline tomweimer

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Re: poor all grain efficiency, don't know why
« Reply #39 on: January 21, 2012, 05:49:02 AM »
I've been brewing all-grain for a little over a year now, all recipe kits from Northern Brewer, and been consistently disappointed with my OG readings when compared to their target OG's. I just brewed their Denny's Wry Smile Rye IPA, which is supposed to be OG=1.078 with 16 lbs of grains.

I brewed this once previously, last year, and came up with OG=1.060. But it was a really good beer so I wanted to try it again. The first time I did a simple single infusion mash, so this time I thought it might help my efficiency to do a two-step with a protein rest. I also thought I might have under-sparged the first time, since I was concerned about collecting too much wort for the boil. This time I decided to stick to my Papazian formulae (1 qt water per pound grain for the mash and 2 qts/pound for sparge), and just boil as long as it took to get down to 6 gallons of wort.

So for all this extra thought, time and work, my gravity came out even lower this time, at 1.050. Just racked this into a carboy last weekend, and it's still a great-tasting beer, but it's bugging me that I can't get close to target gravity. Even for lower-gravity beers I seem to come up consistently short by 0.010 or more.

Reading this thread, I got to wondering about how the grains are crushed, since I don't have a mill and order all my grain crushed. Has anyone else had similar results with Northern Brewer kits (pre-crushed)? Or conversely, had no issues with them, I need get my own house in order?  ;)

Offline malzig

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Re: poor all grain efficiency, don't know why
« Reply #40 on: January 21, 2012, 08:32:13 AM »
I've been brewing all-grain for a little over a year now, all recipe kits from Northern Brewer, and been consistently disappointed with my OG readings when compared to their target OG's...

 ...so this time I thought it might help my efficiency to do a two-step with a protein rest....1 qt water per pound grain for the mash and 2 qts/pound for sparge...

...my gravity came out even lower this time
The changes you made are ones that could lead to lower yield.  The protein rest might have helped, especially if you decocted for the temperature rise, but it's probably not going after the core problem that you likely have, which is poor gelatinization of starch in coarsely ground grain. 

Also, even if increasing the sparge volume helped, it would be due to a more aggressive rinsing of the grain, which could increase your gravity but (potentially) hurt the flavor of your beer.

If you want to try and improve your efficiency with a 2-step mash, when you suspect is a coarse crush, you would be better served doing a 2-step with a beta and alpha amylase rest.  The second rest in the 158-162°F range should improve gelatinization in the difficult to gelatinize coarse grits.

Additionally, using a thinner mash in the 1.5-2 qt/# (I recommend the higher end of that range), instead of that very thick 1 qt/#, tends to improve gelatinization and should help with yield from coarse grits.

One alternate possibility is that you have perfectly good conversion but have channeling in the grain bed.  Switching to a batch sparge for one batch would eliminate this variable and test this possibility.  Also, you should try measuring the gravity of your first runnings against [urlhttp://braukaiser.com/wiki/index.php?title=Troubleshooting_Brewhouse_Efficiency#Determining_Conversion_Efficiency]this chart[/url] to determine your conversion efficiency and better understand your problem.

Offline denny

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Re: poor all grain efficiency, don't know why
« Reply #41 on: January 21, 2012, 09:42:01 AM »
so this time I thought it might help my efficiency to do a two-step with a protein rest.

ARRRRRGGGHHH!  Please, no protein rest with that grist!  You'll kill the beer's body!

I agree that you should use a thinner mash.  Also, it sounds like you;re fly sparging.  Try batch sparging a batch and see if your efficiency improves.
« Last Edit: January 21, 2012, 09:47:50 AM by denny »
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Offline tomweimer

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Re: poor all grain efficiency, don't know why
« Reply #42 on: January 22, 2012, 05:28:35 AM »
Denny and malzig, thanks very much for the tips. Having done a bit more reading on batch sparging, I will definitely give that a try, as well as a thinner mash. My brew system is pretty simple, my mash tun being a 10-gallon cooler with a false bottom and ball valve for runoff, but no way to add heat besides adding hot water. So if I can get away with a single infusion mash, that would make me happy.

Denny, sorry about that protein rest. However, I'm still confident it will make a fine homebrew to relax and not worry with.

Offline malzig

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Re: poor all grain efficiency, don't know why
« Reply #43 on: January 22, 2012, 06:44:20 AM »
My brew system is pretty simple, my mash tun being a 10-gallon cooler with a false bottom and ball valve for runoff, but no way to add heat besides adding hot water. So if I can get away with a single infusion mash, that would make me happy.
I use a similarly simple system, simpler actually, since mine is a cooler with a stopper, dip-tube and a braid.  Doing a step mash is as easy as pouring in the right amount of hot water at the right time.
« Last Edit: January 22, 2012, 09:00:07 AM by malzig »

Offline hopfenundmalz

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Re: poor all grain efficiency, don't know why
« Reply #44 on: January 22, 2012, 07:41:57 AM »
Denny and malzig, thanks very much for the tips. Having done a bit more reading on batch sparging, I will definitely give that a try, as well as a thinner mash. My brew system is pretty simple, my mash tun being a 10-gallon cooler with a false bottom and ball valve for runoff, but no way to add heat besides adding hot water. So if I can get away with a single infusion mash, that would make me happy.

Denny, sorry about that protein rest. However, I'm still confident it will make a fine homebrew to relax and not worry with.
A friend who makes award winning beer has a system like that.  Once his mash tun is full, he mashes out by pulling the liquid and bringing to a boil, and puts it back in.  Sort of the thin decoction step.
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