Correlation between wheat malt and efficiency?

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Rob2010SS

Rob2010SS

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As the title states, is there a correlation between using a lot of wheat malt and getting a lower efficiency?

Or...

Is there a correlation between brewing a small-er batch (13.96lbs of grain, 4.5gal of strike water, 10 gal pre boil volume) on a 20 gallon system?
**The amount of grain/water mixture in the MT was extremely small, which is the only reason I'm even asking the question. Probably no merit to this at all...

I brewed an American Wheat this past weekend and my efficiency was garbage. I'm almost embarrassed to type this. Never had it this bad....

3.47# Barke Pils
5.94# White Wheat
4.28# 2 Row
.27# Acid Malt

4.5g strike water at 164F
Mashed for 60 min at 152F

**Neglected to check pre boil gravity on this one, of course. Had another issue with a melted element cord to deal with at the time :no:

Pre boil volume was 10g
Post boil was around 9g
(with the Condenser lid in combination with running boiling wort through my CFC for the last 10 min of the boil, haven't figured out a good way to measure post boil volume. From previous tests, with the lid, my boil off is 1g.)

Target OG post boil 1.044
Actual OG post boil 1.034

Brewers Friend calcs put conversion efficiency around 26-27% (with me estimating pre-boil gravity) and brewhouse efficiency at 57% (based off of 9 gal left in the kettle at the end).

Typically, I nail my OG's on the nose with the exception of a FEW where I've been up to 3-4 points off. 10 points off is heart breaking and I'm trying to figure out what happened. I plan to do some digging but figured I'd get some conversation started here in order to help future brewers as well!
 
Rob2010SS said:
As the title states, is there a correlation between using a lot of wheat malt and getting a lower efficiency?
Click to expand...

Lots of folks report low(er) efficiency with wheat malt. IMO, it's typically due to wheat malt kernels being smaller, resulting in a poorer crush given the same mill gap as for barley malt.
 
You mill the grains at home or at a LHBS? Shop mill gaps are so wide, that the wheat malt would not even get crushed, At my local, the mill loses it's gap a lot too and even barley malts go through uncrushed a lot. At home, best bet would be to mill the regular grains, then reduce your gap and then mill the wheat.
 
jdauria said:
You mill the grains at home or at a LHBS? Shop mill gaps are so wide, that the wheat malt would not even get crushed, At my local, the mill loses it's gap a lot too and even barley malts go through uncrushed a lot. At home, best bet would be to mill the regular grains, then reduce your gap and then mill the wheat.
Click to expand...
Unfortunately, I'm at the mercy of the LHBS. The shop I used to use, they let you go and measure out your own grains and mill your own. You weren't allowed to adjust their mill though. However, i could at least see what was coming out of the mill.

The shop I started going to, unfortunately, doesn't let you mill. They measure it out and do it all for you. Sounds like the milling was the culprit...? I've done wheat's before at the previous shop I was going to and never had an issue.
 
I wouldn't worry about the BF conversion efficiency, this number is misleading as I believe it reports a conversion efficiency based on a no sparge, first running wort gravity and volume as a percentage of available sugars in the grains. Not particularly helpful since we recover a lot more sugars that were converted in the sparge process. (Someone please tell me if I am misinterpreting this)

57% for the brewhouse is still a bit low and the other replies about milling of the smaller wheat kernels are probably right on. It is worth the time to mill wheat (or rye) separately with a tighter gap, coffee grinder, or whatever means you have available.

The other factor could be system losses which requires accurate volume measurements to determine. How much water was left in the mash tun that held back available sugars. Try checking gravities of the last wort coming out of your mash tun. If you can get down in the 1.010 to 1.015 you're doing pretty good for the sparge. If its much higher, some of you low efficiency may be sparge process issues.

Rob2010SS said:
Brewers Friend calcs put conversion efficiency around 26-27%
Click to expand...
 
VikeMan said:
Lots of folks report low(er) efficiency with wheat malt. IMO, it's typically due to wheat malt kernels being smaller, resulting in a poorer crush given the same mill gap as for barley malt.
Click to expand...

It's also because wheat malt has some starches that gelatinize much higher than normal mash temps, and its one of the reasons why decoction is almost always used for Weissbier production in Germany (gelatinization of those hard to get starch granules, via boil (or close too)) .
 
hmbrw4life said:
It's also because wheat malt has some starches that gelatinize much higher than normal mash temps, and its one of the reasons why decoction is almost always used for Weissbier production in Germany (gelatinization of those hard to get starch granules, via boil (or close too)) .
Click to expand...

Maybe. But my wheat beers always seem to get the mash efficiency I'm expecting (by grain bill size), and I don't normally decoct. Do you have a source of information on the wheat malt starches you mentioned?
 
I agree with @VikeMan. If the crush is good enough, wheat and other adjuncts will convert just fine. Pretty sure I've exceeded 90% efficiency more than a few times on my wheat and rye based beers, with no decoction or special treatment other than a kickass crush.
 
It's actually only a few degrees (Celsius) higher if at all. It's all linked to the higher protein content as proteins bind up starch granules and dealy gelatinization.
 
VikeMan said:
Maybe. But my wheat beers always seem to get the mash efficiency I'm expecting (by grain bill size), and I don't normally decoct. Do you have a source of information on the wheat malt starches you mentioned?
Click to expand...
Kunze 7.3.1.2 off the top, I have seen it referenced other places as well.
 
dmtaylor said:
I agree with @VikeMan. If the crush is good enough, wheat and other adjuncts will convert just fine. Pretty sure I've exceeded 90% efficiency more than a few times on my wheat and rye based beers, with no decoction or special treatment other than a kickass crush.
Click to expand...
Gelatinization is a physical, heat-driven process. It's not enzymatic. No matter how small you crush corn (corn starch, corn flour) doesn't mean it will gel at 150. To cite one example.
 
hmbrw4life said:
Kunze 7.3.1.2 off the top, I have seen it referenced other places as well.
Click to expand...

If you happen to run across one of these references online, please share. Kunze is a little pricey for me.
 
catalanotte said:
The other factor could be system losses which requires accurate volume measurements to determine. How much water was left in the mash tun that held back available sugars. Try checking gravities of the last wort coming out of your mash tun. If you can get down in the 1.010 to 1.015 you're doing pretty good for the sparge. If its much higher, some of you low efficiency may be sparge process issues.
Click to expand...

I don't think it's this. While I don't know accurate volume measurements on my system, I do know ballpark numbers and I usually hit my OG's spot on with a rare exception. I think I have my system figured out pretty well.

I do think crush has more to do with it than anything. This is the first time using wheat from a new shop. I've used the same amount of wheat from my other shop with no issues. I just need to bite the bullet and get a mill...
 
hmbrw4life said:
Kunze 7.3.1.2 off the top, I have seen it referenced other places as well.
Click to expand...
This is a useless reference for most homebrewers, since Kunze is beyond the budget of most. Also a proper reference quotes the applicable information, and then gives the source of the information.
hmbrw4life said:
Gelatinization is a physical, heat-driven process. It's not enzymatic. No matter how small you crush corn (corn starch, corn flour) doesn't mean it will gel at 150. To cite one example.
Click to expand...
Gelatinization starts at temps significantly below the published gelatinization temp. Gelatinization doesn't abruptly start at a specific temperature. Gelatinization temp is determined by Differential Scanning Calorimetry (DSC). The temp that DSC spits out is the temp where reactant exhaustion takes over as the most significant factor instead of the increasing rate vs. temp of what's being measured - in this case gelatinization. DSC is conducted with temperature ramp rates of 5 - 10°C/minute, so is not very good at describing what happens at static temperatures.

Brew on :mug:
 
Rob2010SS said:
As the title states, is there a correlation between using a lot of wheat malt and getting a lower efficiency?

Or...

Is there a correlation between brewing a small-er batch (13.96lbs of grain, 4.5gal of strike water, 10 gal pre boil volume) on a 20 gallon system?
**The amount of grain/water mixture in the MT was extremely small, which is the only reason I'm even asking the question. Probably no merit to this at all...

I brewed an American Wheat this past weekend and my efficiency was garbage. I'm almost embarrassed to type this. Never had it this bad....

3.47# Barke Pils
5.94# White Wheat
4.28# 2 Row
.27# Acid Malt

4.5g strike water at 164F
Mashed for 60 min at 152F

**Neglected to check pre boil gravity on this one, of course. Had another issue with a melted element cord to deal with at the time :no:

Pre boil volume was 10g
Post boil was around 9g
(with the Condenser lid in combination with running boiling wort through my CFC for the last 10 min of the boil, haven't figured out a good way to measure post boil volume. From previous tests, with the lid, my boil off is 1g.)

Target OG post boil 1.044
Actual OG post boil 1.034

Brewers Friend calcs put conversion efficiency around 26-27% (with me estimating pre-boil gravity) and brewhouse efficiency at 57% (based off of 9 gal left in the kettle at the end).

Typically, I nail my OG's on the nose with the exception of a FEW where I've been up to 3-4 points off. 10 points off is heart breaking and I'm trying to figure out what happened. I plan to do some digging but figured I'd get some conversation started here in order to help future brewers as well!
Click to expand...
Since brewhouse efficiency is always less than or equal to mash efficiency, and mash efficiency is always less than conversion efficiency (since lauter efficiency is always less than 100%) your efficiency numbers, in particular your conversion efficiency values are bogus.

To measure conversion efficiency you have to know your strike water volume, grain bill weight, grain bill weighted average extract potential, and end of mash SG (before addition of any sparge water.) If you don't have all of those measurements, then all you can calculate is mash efficiency (if you have grain bill wt, grain potential, pre-boil SG, and pre-boil volume. Post-boil values can be used in place of pre-boil.)

For roughly 14 lbs of grain with an average potential of 37 pts/lb, we have 14 * 37 = 518 pts of potential extract. 9 gal at 1.034 gives 9 * 34 = 306 pts of extract collected. That gives a mash efficiency of 306 / 518 = 59%.

For your grain bill and pre-boil volume with sparging, 89% is not an unreasonable assumption for lauter efficiency. Making this assumption says your conversion efficiency is somewhere around 59% / 89% = 66%, which is very low. Good conversion efficiency is 95 - 100%.

(The above ignores the moisture correction you need to apply to get truly rigorous calculations.)

Brew on :mug:
 
Last edited:
hmbrw4life said:
Kunze 7.3.1.2 off the top, I have seen it referenced other places as well.
Click to expand...

Ok, a kind soul let me have a peek at that section of the english v5 edition. It's titled "7.3.1.2 Wheat beers (Weizenbiere)" and here's what it has to say about mashing:

"The mashing procedure used today by some 60 % of breweries, despite the somewhat difficult protein breakdown, is an infusion mash process (or single decoction mash process) with a mashing-in temperature of 35 -37 °C and an intensive protein rest of up to 30 min at 45-50 °c. Mash boiling lasts 20-25 min. The main wort mashing ratio is 1 : 3 to 1 : 4. Final attenuation is 78-85 %. For favourable mashing processes for wheat beer, see Section 3.2.4.3.1 and Fig. 3.69."

It doesn't mention wheat gelatinization temps per se. And a look at the Section 3.2.4.3.1 it references... titled "Single mash processes" but is about mashing in general (not specific to wheat) and also doesn't mention gelatinization temps.

Is the quoted paragraph above what you are referring to?

Mods: I think this is "fair use" but please delete if you disagree.
 
hmbrw4life said:
I'm actually done posting anything. Congrats HBT it worked!
Click to expand...
It's not about being right. It's about having the right information. I came here because I brew with wheat. A lot. And I also have issues with low efficiency that I'm trying to improve.

I'm immensely glad to have knowledgeable and active members like @VikeMan and @doug293cz sharing and somethimes straightening things up. It's a forum. Means we have discussions. Literally.

Also, the magical words are: oops my bad. I didn't understand that thing properly. Thanks for your time!

Cheers.
 
I've experienced that I have one hell of a time trying to get raw wheat to convert in a 60 minute 152-156 degree mash. Every time I've used it, it wouldn't convert and I'd miss my Pre-boil and subsequently my OG.

I've heard you've got to do a mash rest at 120 for 20-30 min before your desired mash temp, haven't tried it however....but I still have 8lbs of it sitting in my grain inventory.
 
hmbrw4life said:
Gelatinization is a physical, heat-driven process. It's not enzymatic. No matter how small you crush corn (corn starch, corn flour) doesn't mean it will gel at 150. To cite one example.
Click to expand...
True. However, wheat does not require boiling to gelatinize.

http://beersmith.com/blog/2013/09/06/cereal-mash-steps-for-all-grain-beer-brewing/
iqvjO.jpg
 
Re: Corn Mill
Rob2010SS said:
I have not. But I may have to get one..
Click to expand...
Takes a while to mill 20-24# of grain (for a 10 gallon batch) on one of those corn mills, especially with a hand crank.
I think you'd be much happier with a 2-roller mill,* powered by a drill or dedicated motor. You'll never look back.

Plus I buy malt by the sack, not by the pound. That has earned back the investment of the mill 2 times over, easily.

jdauria said:
At home, best bet would be to mill the regular grains, then reduce your gap and then mill the wheat.
Click to expand...
That's what I do. Being able to quickly change the gap width (less than a minute) on my 2-roller mill* makes it a no-brainer. Not just for wheat, any small kernel grain such as Oat malt, Rye malt, Triticale, benefits from an accordingly tightened gap. I enjoy 82-85% mash efficiency regardless of grain size.

When done, I leave it where it is. So generally I need to reset the gap once during each milling session.

* Note: From what I've read some (most?) 3 roller mills are not as easy to adjust, keep that in mind.
 
IslandLizard said:
Re: Corn Mill
* Note: From what I've read some (most?) 3 roller mills are not as easy to adjust, keep that in mind.
Click to expand...

You are correct, 3 roller mills are not as easy to adjust. I have one and it requires me to remove the hopper in order to measure the gap. However, I have not had an issue with wheat malt not getting crushed at my normal setting with the 3 roller. But I also condition my grain (spritz with water 10 minutes before milling) which helps plump up the grain slightly.
 
FYI conditioning only makes sense if there is a hull to condition. Wheat malt is naked and all you're achieving by conditioning it is making a mess in your mill.
 
I'm going to necro this recently deceased thread to throw out another possible factor that was not mentioned here

I recently learned thanks to Silver is Money and Vikeman that wheat has a DI ph value of about 6.1. If you are using a significant proportion of wheat in your mash, this is enough to drive your pH up significantly unless you compensate with additional acidification.

For example I recently brewed a beer with a grist composed of 77% Maris Otter and 20% wheat and 3% Honey malt with an intended OG of 1.080 and this required 5.5mL of 88% lactic acid to keep the pH in spec at 5.4. Had I acidified using Beersmith's built in calculator, I would have added only 2mL of 88% lactic. This would have resulted in an actual mash pH of 5.65.

So it seems the most commonly used brewing softwares do not account for the large alkalinity contribution of wheat, which could be a contributing factor. FWIW this beer's efficiency turned out exactly as predicted at 66% (normal for an OG this high on my system)
 
I haven't had any issues with wheat malt itself, more so raw wheat berries. The last time I used raw wheat (in attempt to use up what I had left), i had to mash for about 1.5-1.75 hours to have it convert.
 
Genuine said:
The last time I used raw wheat (in attempt to use up what I had left), i had to mash for about 1.5-1.75 hours to have it convert.
Click to expand...
Raw wheat (as well as most other raw, unprocessed grain) needs to be pre-boiled or cereal mashed before it can be used in mash, due to high gelatinization temps. Even flaked corn benefits from a 30' preboil (or cereal mash). Your extended mash duration may have helped getting sufficient gelatinization before it could be converted, as does finer milling.
 

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