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Old 05-14-2009, 06:39 PM   #1
ghpeel's Avatar
Jan 2009
Gainesville, FL
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Hi all, I really respect you experienced guys here and I want to ask your opinion......

I have been doing a partial-mash almost-all grain process for several batches in a row and have had really REALLY high efficiencies (just did one today that's like 90-something maybe?), so much so that I am worried that either my methods of calculating them are wrong, or that I am doing something that will negatively impact my beer (although 3 of my 5 batches like this are tasting good).

My method revolves around 7 to 7.5 lbs of grain. Mostly the base grain plus flavoring grains. I add to this 1-3 lbs of dry extract or sugars (panela, sucrose, etc), depending on the recipe and the final gravity that I need.

To mash, I pour my 7.25 lbs of grain into a paint strainer, put it in a cooler and then mash in with 13 quarts of water, at usually 166F or so, to hit my starting temp. I use 5.2 stabalizer, and stir the mash every so often. After 60 min I pull the grain bag out, let it drain for a sec, then dump that first wort into my kettle. This grain to water ration equals about 1.8 qts / lb. Its sort of in between traditional mashing and BIAB.

I put my drained grain bag back into the cooler and sparge with 12-13 qts 176-180F water, which brings that grain mass back up to 170F or so (I think this is were my efficiency really goes up). I stir that thing real good for a bit, and after 10 min I pull the bag out and dump that wort into the kettle too.

So my efficiency with this is usually 82% but today I did everything as normal and ended up with maybe 91%??? Here was the recipe for my Duvel-like ale:

In the mash
7.25 american pilsner
1 lb Dry malt extract (yes, in the mash)
4 tablets Beano (do they affect efficiency?)

In the kettle (last 10 min or so)
2 lbs table sugar (Yeah!)

Jamil Zanisheff(sp?). advises to re-mash your extract with your base grains when doing a partial mash that you want to get really low final gravity on. Weird huh! He's the most award winning home brewer active today and actually uses 3-F'in POUNDS of table sugar in his 6 gallon batches of Golden Ale.

So I was shooting for a gravity of 1.069 - 1.070 and instead I hit 1.077!

I weighted out the sugar, and I am also very sure that the brew store guy gave me exactly 7.25 lbs of pilsner, so my question is this: what is causing this efficiency to be this high?? Am I measuring it wrong or something??

I have been brewing for almost 2 years now, and when I started, I used kits exclusively. I would always measure the beer's gravity, and my gravities (since I was using all extract recipes) would match the exact gravity that the kit advertised, so I know how to take a reading (65 degrees, adjust if hotter or colder, spin to dislodge bubbles, etc).

So if my efficiency is this high, am I "over-sparging"? In light of all the awesome Brew-In-A-Bag stuff, I don't think so, as they mash with ratios like 3qts/lb and such.

I've done 5 batches (including my 90%er today), and all have been 80% eff and up, except for one that i missed my 'mash out' temp by about 6 degrees. That one was about 70% and so I think that 170F mashout is really a key here.

Any advice or comments would be awesome ... thanks!

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Old 05-14-2009, 06:52 PM   #2
Evan!'s Avatar
Aug 2006
Charlottesville, VA
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There's a hypothesis out there, promoted at times by JZ, that if your efficiency is too high, you start to extract unwanted things from the tannins, etc. His recipes assume 70%. I routinely get 78-82%, and have noticed no detrimental qualities from it. I think it's just a hypothesis, like much of the stuff that JZ comes up with on the fly during his shows, that has no real quantitative backup. But let us know how it turns out. If it's overly tannic and astringent, then maybe there's something to his hypothesis. I doubt it, though.

Yes, a mashout is important, and yeah, 3 qts/lb is a bit much...but whatever.
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Old 05-14-2009, 07:56 PM   #3
MN_Jay's Avatar
Apr 2008
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Efficiency on partial mashes are kind of a catch-22. One could argue that the DME and table sugars should not be counted in your efficiency calculations since those are fermentables given to you no matter how bad you may or may not screw up. If you are using efficiency numbers as a way to gauge how well your process works, then taking a overall efficiency is not going to help you.

That being said, you probably don't have a problem with oversparging because assuming you got 5 gallons in the fermenter, then your actual grain efficiency is probably closer to 85% after you deduct the PPG of sugar and DME (I got these from beersmith.) That still is great efficiency, so I wouldn't change a thing.

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Old 05-14-2009, 07:58 PM   #4
The Pol
Feb 2007
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Stupid question... if you are mashing 7.5 pounds of grain, why arent you just doing all grain?

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Old 05-14-2009, 08:34 PM   #5
Kaiser's Avatar
Nov 2005
Pepperell, MA
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No you are not oversparging with that technique. It is essentially a one step batch sparge (2 run-offs). The efficiency limit for that is between 90-92% when you brew for 5 gal batches, have a reasonable boil-off and use only 7-8 lb of grain. You can reach this limit when you convert all the starches in the mash which is not difficult to do, especially when mashing thin with the proper pH. batch sparging BIAB does a little bit better than batch sparging in a cooler as the grain will retain less wort due to the absence of any dead space and the slight squeeze that it gets from the bag.

Jamil’s idea of mashing the extract with the grains is correct. The enzymes from the grain will make the extract more fermentable. But you have to make sure that the sugar concentration in that mash doesn’t get too high. Like a thick mash, high sugar concentrations can impede the gelatinization and enzyme activiy.

With respect to the suggestion of a lower efficiency for beer quality sake have a look at what I posted on the AHA techtalk yesterday:

>Its been an ongoing
>discussion about efficiencies in malt extraction here lately. What do
>the pros get? I've been told 98%, but for a lower gravity beer,
>wouldn't this draw out tannins from the husks? What is the best a
>brewer can get without getting off flavors?

Based on what I have come across, large scale commercial breweries can get about 95-98%
efficiency. To get these high efficiency numbers with minimal sparge water use they use
lautertuns that have been optimized for even extraction of the grain bed or they use mash
filters. Modern lauter tuns are generally fitted with rotating knifes and have multiple
drainage points that can be controlled independently.

But if you are at risk for oversparging not does not depend on the efficiency into the
kettle alone:

If you look at the efficiency into the kettle it consists of the efficiency of the
conversion process (how much of the potential extract is realized in the mash) and the
efficiency of the lauter (how much of the realized extract is transferred into the
kettle). Only excessive lautering causes the off flavors that brewers associate with high
efficiency. As a result there is nothing wrong with striving for maximum conversion in
your mash. If that is the case, i.e. you don?t loose a significant amount efficiency in
the mash, all your efficiency losses will be in the lauter.

The amount of efficiency that has to be sacrificed in the lauter for wort quality sake
depends on your lauter system. Losses of 10-15% should be expected for batch sparging
average gravity beers while fly sparging with a simple false bottom lautertun should be
able to be done with losses of 10-5% w/o noticeable negative impacts of sparging.

But complete conversion of the starch in the mash is not a given even if an iodine test
is negative. All the iodine test indicates is the presence of large glucose chains in the
mash liquid. But if you happen to use a coarse crush you may actually have unconverted
starch in large grits or insufficiently crushed kernels. This starch represents lost
efficiency and lowers your overall efficiency potential.

Here is an example that I like to show on this subject:

Let?s assume a brewer shoots for 80% efficiency because he/she wants to avoid
oversparging and the associated excessive extraction of tannins. But this efficiency can
be achieved in multiple ways. For one I can convert 95% of the starches in the mash and
then lauter with 84% efficiency or I can convert only 84% of the starches and lauter with
95% efficiency. Depending on the system a lauter efficiency of 95% may require
oversparging while 84% lauter efficiency is unlikely to have that problem. So in the
first case the wort quality is expected to be better even though both cases yield the
same overall efficiency of 80%

All sparging reduces the quality of the wort and there are a number of brewers that swear
by the no sparge technique. For that the efficiency limit can actually be determined and
it depends on the grain weight, wort absorption in the grain, lauter tun dead space and
the amount of water that is used. For an average gravity beer (1050 SG, 12.5 Plato) and
15% boil-off it is about 72-73%.

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Old 05-14-2009, 10:08 PM   #6
ghpeel's Avatar
Jan 2009
Gainesville, FL
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Originally Posted by The Pol View Post
Stupid question... if you are mashing 7.5 pounds of grain, why aren't you just doing all grain?
I guess I just didn't have good luck with my earlier attempts at mashing, and so I went to a system of using a really thin mash (1.8 qts/lb) to get good efficiencies. With my setup now, I can do everything with a 5-gallon cooler in my kitchen. I just figured that if I move to "real" all grain, then I'll need a bigger mash tun and a gas burner to do full 6-7 gallon boils.

I'd rather keep using 1-2 lbs of extract and keep all my current equipment and be able to stay inside. Plus, I usually end up with 3.5-4 gallons of wort in the fermentor. This means that I can use a gallon of really cold water to top off my carboy, which helps get temps down.

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Old 05-15-2009, 03:03 AM   #7
Jan 2008
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Are you taking precise volume measurements of the amount you're extracting from your grain? Because that's a really important part of accurately computing your efficiency.

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Old 05-15-2009, 03:18 AM   #8
conpewter's Avatar
Nov 2007
East Dundee, Illinois
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I agree that the DME is throwing off your efficiency calculations. Since you always get 100% efficiency with that you need to calculate without that in. I'd use one of the brewing calculators to find out how many gravity points you got from the DME, then I'd subtract that from your FG. At that point you can use the weight of your grains to compare to how much you were able to extract.
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Old 05-16-2009, 01:01 AM   #9
ghpeel's Avatar
Jan 2009
Gainesville, FL
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I should have mentioned how I am calculating my efficiencies: Brew Calculus on - You enter the ingredients and your efficiency and they show you the starting gravity. I worked backwards by doing a recipe, recording my gravity, then seeing what efficiency I would have to be at to hit the gravity that I got.

hopville . Graham Peel's Recipes

I would think think that they calculate dried/liquid extract correctly. Does anyone have any thoughts on how they are doing their calculations? If they are somehow wrong, then it would mean all my recipes there would need to be adjusted.

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