Frozen grain=amazing mash efficiency?

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Frozen grain=amazing mash efficiency?

Postby Fraoch » Sun Jan 05, 2003 12:45 am

OK, i normally get a very good mash efficiency anyway, around 85 - 90%, but for the last 2 brews ive used grain that has been stored in the freezer, i crack it whilst still semi frozen and mash the next day,the results are phenominal as my efficiency has risen by 5% or more, hitting 99 and 97% respectively.Anyone else do this???? or like to try it and offer a second opinion???I find it all hard to believe myself!!
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WOW

Postby dartedplus » Sun Jan 05, 2003 6:55 am

I'll definitely give it a try next time I brew if I can get an extra 5-8% like you claim. We'll have to see what "Mesa The Allknowing" has to say about this. Just kidding Mesa, but you are the professional.

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You Asked For It: "Conditioning" Malt Prior to Milling....

Postby Mesa Maltworks » Sun Jan 05, 2003 9:20 am

Since only heat is capable of beginning the process that leads to saccrification of starches (for brewing purposes), there cannot be any conversion potential enhancement going on. What I believe you have stumbled upon is reduced malt friability (the tendancy of dry materials to be prone to breaking into small shards or fibers) leading to a more complete rinse of sugars.

In some large breweries malt is "conditioned" prior to milling. Conditioning malt is done by barely wetting the barley malt via a very fine mist or steam prior to crushing it. This act serves to retain more of the elasticity of the malt husk. When malt prepared in this way is milled, a greater proportion of the hulls stays intact since their pliable condition allows them to pass through the mill without being broken into pieces. The following advantages are gained since there are more intact husks in the mash: 1) Better vorlauf clarity can be achieved in less time, 2) runoff to full kettle volume can be achieved more quickly and 3)the rinse of sugars entrained in the mash will be more thorough.

After learning of this technique at Siebel and reading further, I incorporated this practice in all of my homebrew batches. I simply misted the grains lightly as they were placed in the hopper of my mill. The results from this small additional task to my brewing day were well worth it ! I have always wished I could do this in brewpub settings, but the equipment designs of these smaller systems make it technically difficult to pull off. The worst part is that since you are introducing water into a mill, you have to clean it and dry it after every use. With a Valley or Phil mill this is easily accomplished with a sprayer, brush and hair drier. But how do you do the same with a fixed mounted, 800+ pound mill with 2 - 60 pound stainless steel rollers?!!!

I believe your experience has resulted from the malt being partially moist when you crushed it, which accidently produced the conditions outlined above, which in turn, allowed you to collect more total extract. This "wetting" ocurred when condensation was produced as the malt was thawing in the warmer air.

I wouldn't count on this as a reliable technique though ! The process of freezing reduces the moisture content of the goods stored. In the case of malt, this makes husks MORE friable in the long run. The longer they are stored, the lower their moisture content will become. I therefore suggest the use of a mister bottle to mist the malts prior to crushing so the results will be consistent.

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Thank you Eric

Postby dartedplus » Sun Jan 05, 2003 6:28 pm

Thanks Eric. That sounds like something I should try, Although it might be a pain in the *** to clean my mill thoroughly afterward without taking it apart, which is something that I really cant do.

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Another factor to consider...

Postby Fraoch » Thu Jan 09, 2003 2:28 am

I notice that when the grain is crushed whilst still frozen it shatters into 2mm or so particles with very little powder or flour produced.this then gives me a much larger surface area ratio and therefore a greater yield and as yet no set mash.As for cleaning the rollers on my grain mill, i havent noticed any difference at all between frozen crush and standard,that is to say that it doesnt "dough" up and remains a fine powdering as it was beforehand which is easily removed using a semi stiff brush.Try it, you never know, it may work as well for you as it does for me.
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Valid observations...but caused by different reasons....

Postby Mesa Maltworks » Thu Jan 09, 2003 2:31 pm

"I notice that when the grain is crushed whilst still frozen it shatters into 2mm or so particles with very little powder or flour produced"

Yes... but this is not due to the grain being frozen while being milled. The friction produced during milling produces heat which would mostly dethaw the grain as it is being crushed. When this occurs, condenstation then forms and makes not only the husk more pliable, but the starch also. The moist starch granules are more shot out of the husk sort of like a pit out of a cherry when conditioned with moisture prior to milling. This moisture also serves to bind any residual dust as well.

"...gives me a much larger surface area ratio and therefore a greater yield "

Actually the starch surface area is reduced as the crushed granules become larger. Picture a grain of salt. If it had, say 6 sides and you fractured it, it now would have more sides. Another example relating to brewing is why boilovers often occur right after dosing pellet hops into wort. The pellets break up rapidly and, due to the increased surface area, create more nucleation sites upon which the up-rushing oxygen bubbles are broken into smaller bubbles increasing the volume of foam quite dramatically.

My recommendations remains the same:

Since freezing dries contents out over time, it is not a good idea to depend upon this as a consistent source of moisture to yield the benefits you desire. It would be better to simply mist the grain as you are milling. This will produce reliable results. This technique, however, will produce more residual moisture in the grain mill than using frozen grain as you have experienced. When mist conditioning malt, my experience has been that the mill requires a rinse and brushing between uses. I highly suggest using a blow drier to dry the mill to preclude corrosion. Most mill rollers are stainless... but the brackets, fitting, bearings and screws are not always stainless and will readily rust.

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Freezing

Postby fitz » Fri Jan 10, 2003 9:31 am

The freezing is expanding and contracting the grains, so it is breaking them down more(microscopically) I found it works in wine making too. If you freeze the fruit, it ferments better.
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thanks but...

Postby Fraoch » Sat Jan 11, 2003 2:49 am

Being hot and humid, it is far preferential for me to freeze the grain than to have sitting around.I seem to remember a previous post by yourself reccomending freezing which is why i started doing it in the first place!!Its all airtight and blah blah so its a great way for me to store left over grain that is extra to my recipe. Eventually they all add up to a free brew and after a years storage for the majority my extraction rate was 95%, so im happy ( VERY!!)Misting the grain may work also but it would seem to me to be a more risky exercise if you are not mashing immediately.After all, damp grain, humid air fungus etc.Maybe it is just too difficult to freeze large amounts of grain which is why in your instance( IE the commercial world) it is far easier to spray. Just a thought, but with results like this im inclined to carry on as i am. If anything untoward happens ill be sure to let you all know but at the moment 2/2 is good and convincing enough for me to think that maybe ive hit upon something.
Cheers,

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Freezing Recommendation was...

Postby Mesa Maltworks » Mon Jan 13, 2003 7:32 am

Considering your climate, I can see why you would prefer to freeze the grain. High humidity and heat will lead to a reduction in potential extract and worse... fusarium and other mold contamination. I believe you are choosing wisely to store your grain in this manner.

The only topic I was addressing in my discussions and recommendations was freezing and why extraction might rise, not storability issues.

The prior recommendation I had made that you mentioned in your last thread regarded left over hops, not grain, but there is no reason why you could not store the left over grain for a short duration in the freezer. In that thread I also mentioned using a vacuum sealer... that is where the airtight part you remembered came from.

I cannot think of anything bad coming from using your methods... and they have been proven through your measurements to be beneficial. What I was suggesting is a way to accomplish the same increases (and possibly more) with greater reliability through malt conditioning.

And, thanks for pointing out my error in assumptions: I am sorry if I was not explicit enough when describing the malt conditioning technique... this is not something you ever do in advance, only as you are mashing in for the afformentioned reasons you outlined. I definitely did not state this in the post !

Freeze On !

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Freezing Grapes... Etc...

Postby Mesa Maltworks » Wed Jan 15, 2003 11:18 am

Funny you mentioned freezing fruit in this thread... I found out this advantage by what I thought was screwing up !

I had bought a bunch of left over grapes from a vintner and stored them in a walk-in cooler. The thermostat failed in the walk in and the grapes slightly froze. I paniced and called the vintner asking if I destroyed the grapes. He laughed and said no, actually I will increase the brix of the must through the freezing. He went on to explain that since the sugars in grapes are trapped behind cell walls in water, the freezing serves to rupture the cell walls and allows the collection of more grape juice from the must.

In grain, though, the material we are trying to liberate is starch, not sugar. The freezing process might dry the starch somewhat and allow it to fracture into more shards, but it is the saccrification process via heat that produces the sugars. This is why I am certain that the benefits Fraoch describes are produced by better lautering that allows a more complete rinse of the converted sugars, not some sort of microbiological modification that allows for more complete conversion of starch. To my knowledge, the only way that is achieved is through the use of enzymes such as those used to produce the low carbohydrate beers that are now appearing on the market. It can occur accidentally via fungal infection of the mash, but it is exceedingly rare.

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Postby DreamWeaver » Sat Jul 31, 2004 9:49 pm

Eff seems to be a bragging right to homebrewers. I'm not really caught up in eff but would like to acheive the best possible for my equipment & procedures. The last few times I checked my eff was around 78 but only compare with brewing notes now. I have read that a max eff under lab conditions at best was around 88. How does one get 99-97 eff? I don't want to seem doubting but is there more than one way eff is calculated and maybe different numbers result?
For example: I checked my last batch using ProMash and got 75... I tried to calculate for the grain analysis and got 77... And I just tried the Beertools Final Analysis and got 70.8. Thats quite a spread. I don't mind being around 75 but who knows what I am missin? That does it... I'm freezin my grains! :wink:
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Efficiency...

Postby Mesa Maltworks » Mon Aug 02, 2004 12:04 am

Efficiency is achieved by a combination of equipment design, mashing & lauter technique and grain amount. Yes, it is true that it is not possible in normal, non laboratory, non-enzymatically modified brewing conditions to reach an efficiency greater than 88~90%. I am going to take a guess that what Fraoch was referring to is that he reached 98~99% of his calculated target gravity.

The efficiency that you are getting is already above that of the typical homebrewer! In my brewery, which has a great 10 bbl. lauter tun, my average is 83%, minimum 78% (when I exceed 700# of grain) just to give you an idea. Most brewpubs land in the 75~80% range.

Don't get too caught up in the calculated efficiency vs. the actual efficiency and then comparing different calculators. These calculators act as simple estimators to give you an idea (ballpark) to ensure that you use enough ingredients to produce enough fermentables to reach your desired target. They cannot accept enough input variables to be entirely accurate. Among the computer programs, ProMash seems to be the most accurate (I use it both at home and the brewery), but it requires a good bit of measurements to dial it in. I have not used the BeerTools efficiency calculator, but if you got a figure with a variance to that degree, I can only suspect that there is not enough variable input considered to produce a comparable estimate of efficiency. But this is an assumption... ask Jeff what their equation takes into account.

When I create a new grain bill, I always start out calculating it manually to build the grist. I then input it into ProMash which has been optimized to my brewing conditions and compare the reasonableness of the values produced. Below the 700# grist threshold, I do not get a statistically significant variance. Above the 700# grist threshold, the ProMash results are more accurate, but I'm only talking about a <=1.5% variance. This efficiency drop is a result of the physics involved in such a large grain bill... very thick mash with reduced hydration, the mass is significantly larger than normally processed in my tun and therefore is much harder to sparge completely and a reduction in collected sugars due to temperature changes during the sparge (~1.5 - 2 hours).

You may be able to achieve a couple of more % upward, but you may create additional problems by trying to "wring" every last drop of extract from the grain. Since you are supposed to stop the runoff at 2.5 deg. plato (1.010 SG) and then top up with water to boil volume (if necessary), this also serves to limit the maximum that you can achieve. If you go below this gravity during runoff, you are getting VERY little sugars and mostly tannins which create harsh flavors and lipids (plant fats) that reduce head retention and interfere with mouth feel.

Hope this helped!

Eric
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why freezing may help Eff

Postby Gus » Tue Aug 03, 2004 11:06 am

When you freeze something that has even a bit of water in it, that water goes from nice smooth liquid phase to a jagged and sharp crystaline phase. These ice crystals wreak havock on cell membranes and cell walls. This is why a foot that has been frostbitten will NEVER live again and must be removed. It is also the reason cyogenics has been so slow to take off. The body with be preserved for hundreds of years but at this time there is no suggestion that any of the tissue can survive the distructive ice crystals. Freezing MAY just be helping the starch free itself from the solid grain and be slightly more availible to the enzymes in solution. You might think of it as a molecular milling. Can offer citations but that would be this humble biologist's guess. However, one 5% jump in Eff is hardly statistically significant. Keep up posted on how reproducible that increase is.

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Formula for mash efficiency.

Postby etbandit » Sun Oct 29, 2006 3:10 am

What is the formular to calculate mash efficency?
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Re: Formula for mash efficiency.

Postby billvelek » Sat Dec 09, 2006 12:24 pm

etbandit wrote:What is the formular to calculate mash efficency?
I don't know, offhand, what the actual formula is, but I think you need to know the sugar profile of your grain first, or at least how much total sugar is contained in a unit of it (for potential gravity) ... Or else you could use a software program like BeerToolsPro. For example, if I lock the program at 100% Efficiency, and then add malts, it gives me the results of what I should have in O.G. Ten pounds of Briess 2-Row in 5 gallons final volume water, at 100% efficiency, yields an O.G. of 1.071, or basically 7 points per pound. So, for example, if you use 8 pounds of Briess and get an O.G. of 1.042, then I would calculate it like this: 10/8 x 42/71= 73.9%

This is a really an old thread, so I hope our posts will attract some attention here. I'm more interested in hearing what the track record has been for the past couple of years regarding freezing grain (original posts in this thread). Does anyone have any more to say about that subject. Were the results reproducible by anyone?

Thanks.

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