Wheat Malt - Much Lower Efficiency?

[MashMasterMike]

Hey all,

Just wrapping up brew day for today and as I was transferring my wort into the fermentor I took a sample for the hydro and to my shock I was waaaaaay off my target OG.

I've been using my current system for several years now and without exception so far my efficiency is 90-91% every time.
This brew is my first wheat beer, and my efficiency was 76%..... missed my OG by nearly 10 points.

I've put it all back in the boil kettle for another hour now which should hit my intended OG. (Which conveniently and coincidentally will also address an issue with not ordering enough bettering hops to begin with...)

Is this normal with wheat malts?

I order my grain from Grain and Grape in Yarraville pre milled - never had a problem before so I assume it's not to do with being milled badly but who knows.

 

[gap]

Depends on the percentage of wheat in the grist. there is usually a slight loss of efficiency. It is prudent to measure your pre boil gravity.

 

[MashMasterMike]

Wheat was 65.2% of grist
Yeah, I usually do but was tackling so many other things while brewing today I didn't bother. I was a bit complacent because I usually nail my OG so just figured it would work.
Kegged an IPA, bottled some Stout (from a keg), made some conversions to my ferm fridge and my keg fridge - everything was going so well up to this point. I was about to high five myself for having such a successful and productive day.....

 

[MHB]

Truth be told, Wheat Malt has a higher potential than Barley Malt, Typically Wheat is 81-85%, good Barley 78-82% (Laboratory yields FGD), mostly because Wheat hasn't got a husk which accounts for about 5-6% of the grain weight.
So you really should have gotten a better yield from a high Wheat grist.
Wheat requires a much more careful milling or you can end up with either too many uncracked grains or too much fines (flour), takes a bit of practice and a lot of attention to detail to get the most out of Wheat.
The shortcut way is to mill the wheat quite fine, to get higher efficiency, then add Rice Hulls or similar to provide the filtering and respectable lautering speeds that you give up by not having a husk that comes with Barley Malt.
These days you would almost be better off doing a BIAB brew with fine cracked wheat.
Mark

 

[goatchop41]

The shortcut way is to mill the wheat quite fine, to get higher efficiency, then add Rice Hulls or similar to provide the filtering and respectable lautering speeds that you give up by not having a husk that comes with Barley Malt.

Would grain conditioning also be a good alternative to stop the grain bed from gumming up, whilst still having a decently fine mill gap?

 

[MHB]

Not really is my first thought - or at best only to a very limited extent at best.
In my experience wheat behaves very differently in the mill to barley, if your settings aren't spot on you will get a hell of a lot of fines, or a lot of just broken in half corns.
Once, as an exercise I mashed a 100% wheat beer in a 3V system. Put the wheat through the mill 4 times progressively finer until it was a coarse kibble with very little fines. Worked well if a bit slow on the sparge. From this I would conclude that how you mill the wheat is most important.
Home mills mostly have very small (<50mm) rollers and have a lot of problems with wheat, either not touching it or turning it into powder(especially if its set for barley and not adjusted). If you or your home brew shop hasten got a very good mill and knows how to use it I would crack the wheat separately (carefully) and combine with the barley before mashing in. Trying to mill the two together tends to give unacceptable compromises and pretty poor efficiencies.

Given that conditioning really gives small improvements unless the malt is milled very fine where it can help a lot (conditioning helps keep the husks fragments larger) and that most wheat beers usually only have about 1/2 as much husk as an all barley grist...
Unless conditioning is a regular part of your process I wouldn't bother. Concentrate on the mill settings is where I would start. Run a little through the mill then have a good look at the malt (tech term is "Hand Evaluation"), be prepared to play around until you get a nice kibble, Start at just breaking a few corns, go through the mill a bit finer (mostly broken corns), and again at need (kibble).
Mark

 

[keine_ahnung]

^ some great input from Mark.

Just a thought or two about the "conditioning"...
As already touched on by Mike, the traditional reasons for malt "conditioning" is to soften the barley husks, so that you can mill finer -> increasing the effective surface-area of starches -> increasing the ease with which the enzymes can work away at them -> increasing effeciency slash reducing required mash times (that later being mostly irrelevant in a non-commercial setting).
With wheat, the above effect then becomes obsolete. = wheat malt is effectively husk-less

Would grain conditioning also be a good alternative to stop the grain bed from gumming up, whilst still having a decently fine mill gap?

As with all things enzyme-related...this is highly dependant on Temperature.
If you're wanting to target the gumming-up effect of wheat, I think it'd be better to do that through the mash.
One of the cruel characteristics of the enzymes responsible for breaking down ß-Glucan (the "gum-substance" responsible for lautering difficulties) is that it's inactived much earlier than the enzyme that sets ß-Glucan free from the Starch-cell-walls.
i.e. ß-Glucanasen - 40-60°C (the Enzymes that break down ß-Glucan
ß-Glucan-Solubilase - 62-65°C (The Enzyme sets ß-Glucan free from the starch, into solution)

Another important factor, is oxygen exposure. The "gum-substances" (not completely sure how they're referred to in the english brewing world. "Gummistoffe"in German, please feel free to correct me on how they're referred to in english) - Pentosan & ß-Glucan react with Oxygen and become even "gummier" - especieally Pentosan.

 

[keine_ahnung]

2 more quick thoughts on your "efficiency".
1. You could consider implementing a decoction mash to help physically break down more of the starch clumps/connections, making it easier for the enzymes to get at them.
2. might be worth looking into how much of your effeciency loss is in the lauter and how much is in the mash.
i.e. are you not breaking all teh starch down into fermentable sugars?
Or are you not getting all of the fermentable sugars out of the mash bed/cake/whatever it's called in english. haha
(or both of the above)
Try tasting the spent mash-bed after for sweetness...

 

[MHB]

keine_ahnung VLB trained?
Always taste your spent grain (its about the only time in brewing where its OK to spit it out) have a look through a handful of the spent grain to, look for really large fragments or worse still "pearls" swollen up uncracked corns. Decent malt will be graded for size and over 98% should be bigger than 2.2mm (from memory) so more than a few uncracked corns is a sign of bad milling, or very poor quality malt.
With good quality well modified modern malt, and the reduced need for lower temperature steps, the action of B-Glucan Solubilase is another argument for mashing in hotter than 65oC, small tradeoff between lost extract and reduced gum formation.

I really believe home brewers pay way too little attention to milling. There is no ones size fits all mill gap and good mill adjustment/practice can change your yield by over 20%. Same can be said for a lot of home brew shops to.
Milling is our first chance to really influence what we will get from a given grain bill, when you think a 20% difference can mean every 5th grain bill is free, its worth paying attention to!
Mark

 

[MashMasterMike]

thanks for the input guys,

Wheat Malt has a higher potential than Barley Malt

Can explain this further please? From Ray Daniels - Designing Great Bears, the section on wheat beers begins with the following:
"...Barley provides more extract to the brewer per pound of grain than wheat does...."
The context of this quote is in relation to the history of using wheat v barley for beer and bread. The point being that historically for the above reason and a couple of others barley was allocated to brewers and what to bakers for reasons of efficiency.
This seems to contradict what you've said doesn't it?

Incidentally, I use Beer Tools Pro to design my recipes. I would have thought that the wheat malt ingredient would be configured to give me the correct extract per gram based on it's specific efficiency or potential...

if your settings aren't spot on you will get a hell of a lot of fines, or a lot of just broken in half corns.

I inspected the spent grain and I did notice quite a lot of half corns and some small ones that were not cracked at all. I'm beginning to suspect it was poor milling that caused this issue.

might be worth looking into how much of your effeciency loss is in the lauter and how much is in the mash

The thing is, my process is well established and was no different with this brew so I should have got the same efficiency outside of any differences caused by differing ingredients.
My system is a copy of Kal's system over at the TheElectricBrewery. 3 x 76l Blichmann kettles, blichman false bottom - the mash is continuously recirculated through the herms coil during mash and then sparged over 1 hour into the boil kettle.

handful of the spent grain to, look for really large fragments

I'm suspecting this was the issue.

Having said all of the above, I found this interesting thread https://www.homebrewtalk.com/forum/threads/wheat-malt-and-mash-efficiency.390214/
Seems to also have been a milling issue there...

I don't have my own mill yet, so I might need to have a chat with Grain and Grape before ordering wheat next time.

 

[MHB]

On balance I would agree with you, its probably poor milling that caused your loss of efficiency. That's without being there and going through everything in detail.

On Ray Daniels, as much as I respect his work - well nobody is perfect
From a couple of old COA's I have on file

Both from Weyermann COA's as attached
Mark

 

[MashMasterMike]

Thanks Mark,

Now I'm curious to know where Ray Daniels came up with this information...I'd just taken this information for granted.

The malt analysis sheets are not something i've invested the time to understand properly yet, but I think you've just spurred me into studying this information.
From some brief reading this morning the as-is coarse grind data is the most relevant for brewers as it removes the impact of the moisture content? Is that your understanding?

Looking at the ingredients list for my recipe, BTP has the Best Malz what malt as 77.49% AICG and the dry basis fine grind of 83% which is pretty much inline with the analysis you've pasted above (and matches exactly what Grain and Grape posted on the product page- this is about 1% higher than the pilsner malt I've used in this recipe.
If that's correctly setup, I'd say it further points to a grind issue.

 

[Coalminer]

Would it be due to the extra husk in barley malt compared to wheat malt?

 

[goatchop41]

Just a thought or two about the "conditioning"...
As already touched on by Mike, the traditional reasons for malt "conditioning" is to soften the barley husks, so that you can mill finer -> increasing the effective surface-area of starches -> increasing the ease with which the enzymes can work away at them -> increasing effeciency slash reducing required mash times (that later being mostly irrelevant in a non-commercial setting).
With wheat, the above effect then becomes obsolete. = wheat malt is effectively husk-less

I wasn't so much looking at it for its effects on extract/efficiency, I was interested due to it being recommended by Braukaiser. He states that it will keep more of the pericarp around the wheat intact to assist with nice flow through the grain bed during lautering/sparging, even though it essentially has no husk.

 

[MHB]

Thanks, I haven't seen that reference to conditioning wheat and its worth a further look, Kai is a bit like Charlie Bamforth if they are talking - shut up and listen - you might not do what they say in all cases but its worth knowing.

MMMike, COA's are really useful, a lot of good information in one place. Yes CGAI (coarse grind as is) is the most useful to brewers, worth noting that what the congress mash regards as "Coarse" is still pretty fine by home brew standards, but is closer to what we can expect from a given malt.
One other important bit of information is the difference between the Coarse and Fine (at the same moisture content) tell you a lot about how well modified the malt is, small difference (say under 1.5%) means the malt is well modified, over 2% and its poorly modified. Well modified malts are better for isothermal mashes, undermodified malts need step or decoction mashes to get good yields.
Under 1% is or was often viewed with suspicion as it can indicate over modification (starch has been used up in germination and isn't available to make extract).
I suspect that this might be changing, if you look at the C/F on the Weyermann Pilsner above. Given the Extract Air Dry is also a Coarse the difference is only 0.5% and there is nothing wrong with Weyermann Malts.
Mark

 

[MashMasterMike]

The more I learn about this hobby, the more I realise how much more there is to learn...
You gotta start somewhere but I laugh at the old days when I first started 'making beer' by just mixing some liquid extract with water and plopping in a pack of yeast.

the difference between the Coarse and Fine (at the same moisture content) tell you a lot about how well modified the malt is

Ahhh right, I've wondered before how one works out whether a malt is well modified or not. I've seen a lot of information about how to treat malts depending on modification but never how to know if they are well modified or not.

I suspect that this might be changing, if you look at the C/F on the Weyermann Pilsner above. Given the Extract Air Dry is also a Coarse the difference is only 0.5% and there is nothing wrong with Weyermann Malts.

I can't see where you are arriving at this value?
It sounds like you are comparing the air dry value with the fine crush value, but that difference is 4.6% (77.7 v 81.3)...?

 

[MHB]

81.3-77.7 is 3.6
Don't forget the "Moisture content" 4.4%
Gives a C/F difference of 0.8%, (the 0.5% was from another COA I had open (sorry) got a folder full of them)
And yes on the amount to learn, I keep saying I know just enough to know how little I do know and how much there is to learn.

 

[MashMasterMike]

ahh right, cos air dried is of course dry.. cheers.