January 25, 2015 - 11:54am
Heat and milling
I am using a grain mill my dad bought in the early 1980's. It is a high speed mill called Magic Mill III. It heats up the flour to around 125dF. Is this detrimental to the nutrients and how does it compare to a stone mill like the KoMo? Otherwise it does a pretty good job even if it sounds like a jet engine starting. Thanks in advance for any information.
Stu
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Which will destroy more nutrients in the flour:
a) A post-milling temperature of 125F?
b) An internal temperature of 205F in the baked loaf?
There are a lot of folks that get really wound up about keeping the flour temperature low because they say that "high" flour temperatures destroy nutrients. I figure anything that is destroyed at such comparatively low temperatures is also going to be destroyed by the higher temperatures caused by baking. My two cents.
Paul
This is what most electric mill manufacturers say too, but I'm not sure if it's like that. Consider this: if you don't burn the nutrients of the grain when you mill it, they get further broken down by the fermentation process, contributing to the final result. So whatever ends up in the oven is quite different than what it was when it came out of the mill. I don't know if this is a fact, this is just my reasoning.
Any nutrients that would be destroyed by the milling would, like Paul suggests, also be destroyed by the temperatures of baking.
However, the milling process could destroy/deactivate certain enzymes in the grain that are temperature sensitive, which can affect the fermentation process. For example, it is recommended that sprouted grains be dried at a low temperature--below 104 degrees Fahrenheit--in order to preserve the enzymatic activity resulting from the process of sprouting. Granted, pretty much everything is going to die during the bake, but the bake is only a single step in a more complex process.
There are still a lot of question marks surrounding the transformative magic of fermentation, but we do know that the presence of certain enzymes, bacteria, and yeasts are deconstructing and munching on starches in very particular ways, producing very particular byproducts, which ultimately determine the final product--in terms of taste, texture, nutrition, etc. That's not to say baking doesn't play a role, just not necessarily the main one. What I want to emphasize is that the MOMENT at which you axe the micro-organisms and enzymes does matter.
So, briefly, the milling is no more detrimental to the nutrients than the baking. But it will certainly be detrimental to certain enzymes. One way to mitigate this problem is to freeze your dry grain overnight, or for several hours, before grinding it. The flour will still come out warm, but probably not nearly as hot as it is now.
Enzyme destruction by high temperature milling is undoubtedly detrimental to the fermentation process and for this reason I mill at a level of fineness that does not exceed 110°F. If I want a really fine flour (using a Komo mill), I make two passes. The first to coarsely break apart the grain and the second for finer milling. This allows the grain/flour to stay cooler than it would in just one pass with the stones set to mill finely.
Jeff
when it comes to diastatic enzymes and temperatures. Making beer and making bread use the same enzymes The term “diastatic” refers to “diastase” enzymes. The first is alpha amylase and the second is beta amylase. These enzymes are the ones required to break starch down into the sugars that yeast can utilize to make alcohol and CO2.
The difference between bread and beer making is the amount of these two enzymes you want and need to do the job at hand well. For beer making you want as much of them as possible. Too get then you malt the grain for 4-5 days which increases the diastatic power of the grain to a great degree. The mashing process of making beer is where as much starch in the grains is converted into as much sugar as possible since the yeast convert more sugar into more alcohol and CO2 - the goal of making beer. This mashing process happens when water is added to the malted grain and the temperature is raised to 148 to 158 F,
The reason that these temperatures are used is because the enzymes created by malting the grain work best at them, the mashing process is more complete and it happens faster.. Obviously these higher temperatures do no kill off the enzymes but higher temperatures will.
The goals of diastatic power in bread making are quite different. You don't want to convert all the starch to sugar and all the sugar to as much alcohol and CO2 as possible. If you used the 4-5 day sprouted and malted grains for beer in your dough, it will turn to beer goo instead of bread. So sprouted and malted grains used for bread are sprouted for 24 hours until the grain just c'hits'.
This keeps the diastatic power of the malted grain down to a more controllable level when it comes to fermentation and proof. Millers put in about .6 of 1% malt to their white flours - a tiny amount and they usually put none in whole grain flours since it isn't required as the existing diastatic power of the unsprouted grain used for the flour hasn't been removed in the milling process.
So, if you are sprouting, drying and milling your grain for bread, it is best to just 'chit' them for 24 hours or less if the white sprouts just break the skin of the grain and dry them at 125 F to be safe in case you can't control the temperature well enough to keep it under 150 F .
The non diastatic malts are used in beer and bread making for color and flavor. These various degrees of darker malts happen when the 'white' diastaic malts are dried at much higher temperatures for longer times to make 'red' or crystal dark malt types with the darker ones known as chocolate ore even double chocolate. These dark, non diastatic, red malts are what give darker beers, from amber to stout to porter, their color and flavor just like they do for bread.
The difference is that you can't make beer or bread with just non diastatic malted grain since all the enzymes needed to convert the starch to sugar have been killed off from the high temperatures used to dry and color the grains. So you have to mix them with diastatic malted grains or non malted grains in the right proportions with the right diastatic power to make beer and bread.
Good information and much what I intuited also being a brewer.
Thinking along the line of upper limits, and knowing 150 F is going to be safe in a wet environment, do you have any idea if there are higher temperatures that enzymes would easily survive in a dry medium? Although i don't really know, it seems you should be able to take dry grains or flour over 160 F if there is very little moisture present. Care to hazard a guess? 170? 180?
for these enzymes but I don't know what they are . There may be other things going on at 150 F like nutrient or amino acid or other compound degradation might be happening.
Even 1% - 14 % water in dry grain is still quite a bit. for chemical reactions at temperature to take place
Happy Baking
I have a similar mill. I measure 8 cups of berries(the hopper capacity) and put them in a ziploc bag and in the freezer for a while. It helps a lot. High temps can cause some starch damage and the resulting flour will indeed turn to goo. In winter, i just put them outside ( Wisconsin).
...from home milling grain.
Simply pouring the fresh milled flour from the flour receptacle into a large bowl from a height of about 12 inches will immediately reduce the temperature by at least 10 - 15 degrees Farenheit. Stirring the flour will further reduce the temperature of the flour.
Home millers can control the temperature of the flour with ease.
Those who purchase whole grain flour (or high extraction flour) have no information about the temperature of the flour as it emerges from the milling process or whether the miller takes any steps to *rapidly* cool the temperature of that flour.
CAVEAT - I admit to being a tad cranky as I write this, but I do honesly feel that - for the home miller - the temperature of the flour as it emerges from the mill is *not* a major consideration.
You would be very surpised by how cold the commercial roller mills run.
If you have any reliable documentation about the flour temp from commercial flour mills in the USA I would be *extremely interested* in the sources so I could check them out.
I have spent countless hours / days / months / years searching for this info. If you would so kind as to give me a list of your sources for your statement I would be very appreciative.
Looking forward to your response - SF
I do not know if there is anything definitive published in English - mostly what you will see is multiple references to the fact that temperatures over 30 °C have a significant adverse effect on flour yields. If you are really, really interested in very detailed info, I have data sheet that shows temperatures throughout the entire process - every stream before and after every system, with roller temperatures included, but it's not in English.
hi Suave
Thanks for your post - I'm very interested in your data sheet - what language is it in?
I'm confused that references say
Looking forward to your response - SF
Edit - To clarify my statment I should have said that many electric flour mills heat the the flour higher than 30C (specifically the micronizer style home mills). A hand cranked mill is going to be cooler since most of us can't continuously crank it fast enough to generate much heat.
High-end, expensive electric home mills designed with a fixed groove plate and a rotating groved plate don't (to my knowledge) have the ability to vary the rotational speed of the plate (just adjustment for how coarse or fine the output will be). I would guess that mills with this design would not heat the flour during milling as much as the micronizer type mills.
I believe that any discussion about nutritional losses needs to start with determining what nutrients we are talking about and what overall diet looks like.
Check your PMs
"A study by the Center for Food Technological Research Institute in Mysore, India, found that stone-ground flour reached temperatures as high as 194 degrees, and roller-milled flour got only as high as 95. The researchers found that stone-ground flour lost more essential amino and fatty acids."
That's a BS study, which has little to no relation to reality - if you bother to read that paper in its entirety you will see that they used small and relatively crude lab mills, and there's no way you can judge commercial process based on their results.
The "BS" here would be your flippant, off hand, negative and abrasive opinions so easily thrown into this forum year after year after year. Comments that add little or nothing to further knowledge on the subject at hand.
Possibly this work will be more to your liking.
Jeff
https://books.google.com/books?id=FwgtAAAAYAAJ&pg=PA15&lpg=PA15&dq=flour+milling+temperature&source=bl&ots=dY3Y-hO47L&sig=FVGZTpNkG91PenO9nj40LNFvEMc&...
I do not really care - it's up to you what do you like better - a set of data that's 135 years old and was produced in a way that's not really clear, or set of modern data that was produced in a way that's not clear at all (I know that because I read the actual article back when it came out, and not the USA Today digest). You don't think that study is bad? Look up the original and find out what mill did they use, at what loads and speeds, what was the temperature of the mill, and whether it was stabilized. None that info is really there.
Quoting the guys who really knew their stuff: "Experimental flour milling can be only as meaningful as the experimental miller makes it."
PS. As to ad hominem stuff. I told you this before, but it bears repeating. I have nothing against you whatsoever, but whenever you, or anyone else for that matter, will be trying to pass questionable factoids for the ultimate knowledge I'll be there.
8 cups of grain in the hopper, room temp 75F,wheat berries at room temp, after 8 cups berries ground on finest setting in Wondermill( took about 6 minutes), the resulting flour was as hot as 140F with a slightly brown (scorch?) mark where flour discharged into bowl. Flour quickly came down with vigorous stirring and pouring from spoon from a height of 12 in above bowl.
Same scene but wheat berries spent 3 hours in the freezer-resulting flour was 90F.
Is the first batch of flour damaged or did it cool down fast enough?
By the way-Let's keep it civil!
Sorry about responding to such an old thread.
The first phase is determining the temperatures, and perhaps ways to reduce the output flour temperature - milling in two phases, milling frozen grains, perhaps re-freezing the grain after the first coarse milling, stirring the flour and what not.
The second phase is determining what the temperatures mean. Again, there are two approaches.
The first approach to determining the consequences of heat would be a micro-biological or chemical assay to determine what changes there are to enzymes and nutrients in the warmer and cooler flours.
The second would be to actually bake bread with the different flours and see if the results are different. Are the breads different? Is one bread better? And here again we need to consider what we mean by better. A better rise? Better flavor? A better nutritional profile?
-Mike
Clazar 123 has the essence of my question which wasn't as clear as it should have been. Typically about 2 pounds of wheat berries are milled which takes about three minutes then immediately sifted for a 95% extraction flour. Is that short time at an elevated temp enough to significantly damage it?
Thanks for all your responses.
Stu
I'd say the first question you need to answer to yourself is what nutrients you are looking to get from ww that you are not already getting from other foods.
I don't home mill, but I do visit a local mill that uses a pair of water driven stones to mill their flour. I've felt flour coming directly off the stones and it's warm, but no-where near hot. However by the time it gets to the bag (where I've felt it), it's dropped down a 3 meter chute. Might take my IR thermometer when I visit them next time to collect some of their nice wholemeal flour and check it where I can. (There is a window through to the stones too, but all you can see is the top one turning.
It's a great place to visit if ever in Devon, UK. http://ottertonmill.com/
Filling the 25Kg sacks underneath the stones.
-Gordon
"All enzymes are deactivated at a wet-heat temperature of 118 degrees Fahrenheit, and a dry-heat temperature of about 150 degrees. It is one of those happy designs of nature that foods and liquid at 117 degrees can be touched without pain, but liquids over 118 degrees will burn. Thus we have a built-in mechanism for determining whether or not the food we are eating still contains its enzyme content."
http://www.realmilk.com/health/enzymes/
Poor brewers! It turns out they wasted centuries keeping their mashes at 150 degrees, waiting , in vain, for the starch to convert. If only they knew.
It's a shame they did not have the internet where they could waste their time making snide senseless remarks.
This forum has shown itself over time to be made up of 99.9% great folks looking for answers to baking questions and also answering baking questions. Helpful, friendly, and courteous are words I would use to describe the overall forum. A 100% would be nice and you could do a lot to get us there.....or not.
Facts are cold, but I hardly ever thought of them as snide. In this case the cold fact is that some of the most important enzymes in bread-baking not only do not die, but thrive at 150 degrees. I think this information is very helpful to 99.9% of users here, those who would prefer to believe scientist rather than charlatans.
the important enzymes that break starch into the sugars and extract the most sugars from the grain for the yeast to convert into alcohol not only stay active at 150 F in a totally wet environment but, they also work at their very peak at doing so at this temperature. This is why brewers have use this temperature for mashing for centuries - it is the most efficient and takes the least amount of time and one thing beer and alcohol lovers want is to make them faster - especially when you are out!
.These are also the exact same enzymes we bakers love to do the same thing except we don't want all the starch turned into sugar to extract the most alcohol from the grain just enough to do the job of providing the sugars that LAB and yeast like to feist on to mane acid and CO2.
Sadly, as s is often the case, the internet can often be wrong and, in this case, starts with the superlative 'All' when only some enzymes are deactivate in a wet environment at 118 F and only some are deactivated in a dry environment at 150 F. These fine ladies are obviously not brewers or they would know better .