The Fresh Loaf

News & Information for Amateur Bakers and Artisan Bread Enthusiasts

Home Tempering, Grinding, and Bolting Wheat to get High Extraction Flour

ZD's picture

Home Tempering, Grinding, and Bolting Wheat to get High Extraction Flour

Wheat Tempering

Success begins with perfectly tempered wheat. Tempering consists of adding water to dry grain and allowing the grain to rest for a period of time before it is milled. The purpose of tempering is to toughen the bran and thus make it resist being broken into small particles during milling and to soften or "mellow" the endosperm and make it easier to grind. It also helps obtain bran with lowest possible starch content and flour that has ideal quality and higher extraction.

Temper at 77°F or longer if colder. Cooler temps increase flour output and ash. Hotter temps shorten tempering time and can improve gluten properties. 72 hours is not too long to temper.

For milling it is essential that the tempering water is fully absorbed and evenly distributed in the endosperm. Too short a tempering time results in more granular flour, and more power required to mill. Don't mill cold wheat. Milling cold wheat will tend to cause the bran to shatter and not flake off making it hard to sift off.

Ideal Moisture and Tempering Time

For roller mills

- Spring Wheat: 17.5% / 48 - 72 hrs.
- Hard Wheat: 16.5% / 36 - 48 hrs.
- Soft Wheat: 15.5% / 12 - 24 hrs.
- Durum Wheat: 17.0% / 4 - 12 hrs.

Use lower percentages for other milling methods.

These moisture levels may seem high. These are not necessarily the moisture levels used at commercial mills. They can't sell flour with a moisture level over 14% as it is much more likely to mold, draw insects, and have bacterial problems. This is not and issue for home milling if you are going to use in right away. Try to use your flour within 24 hours of milling.
The bite method

What moisture level is the grain you are starting with? No grain moisture meter? No problem. Take a couple grains of your wheat and bite it. The harder the grain is more water it will need to be tempered with. Long ago millers didn't have moisture meters. They used the bite method. Practice and learn the feel of grain. To achieve ideal tempering is to learn to feel and to observe.

How to Temper

Add the desired amount of water to wheat cover container and shake until water is dispersed and for 10 seconds every minute for 5 minutes. Don't add more that 5% per day. Temper at 77°F for 2 to 3 days. If your temperature is much lower than 77°F add a day.


Warning! Protect your mill. Don't grind any grain in your mill you are not comfortable with. You know your mill better then I do. Grind at your own risk.

I used Wheat Montana Hard Red Spring Wheat for the milling tests.

Impact Mills

Every one says don't temper wheat for impact mills, but I have used my impact mill with estimated moisture of 14% and it worked great. About 9% of the bran was large and sifted out easily. I also tried 20% moisture in the impact mill and I think it was too high but it didn't ruin the mill and was not hard to clean up. It also had large bran but not an improvement over the lower moisture batch.

Bur Mills

The Kitchen Aid Grain Mill (KAGM) worked well but not as well as the impact mill. It has very limited ability to grind fine.

Stone Mills

The Wonder Junior Mill is hand cranked and it is easier to mill if the wheat is tempered. It works well at 13% to 15% moisture. I ran 20% through it and it glazed the stones. They were easy to clean with water and then let dry.



Bolted Flour aka High Extraction Flour

Bolted flour contains almost all of the germ, and the softer parts of the bran. Bolted flour was historically sifted through a piece of cloth. It is now typically sifted through a metal or plastic screen. The higher the percentage the closer to whole grain flour it is. The total flour out of the sifter divided by the total grain in to the mill would give you the extraction percentage. 100% extraction is whole wheat.

Home grinding and bolting wheat will get flavor that can't be beat.

History of flour bolting

After grinding sift your flour through a sieve. I have a 55 mesh I got here. also a 30 mesh I have had for years. Using a magnifying glass helps to inspect your work.

I have been tempering 10% moisture HRS wheat to 15% moisture by adding 50g of water to 1000g of wheat and putting it in my 80 °F proof box for 3 days. Grind the wheat in my impact mill on fine. Sift through a 30 mesh sieve and remove about 9% pure bran. Sift through a 55 mesh sieve and save the 74% very white flour. Take the middlings that were caught by the 55mesh sieve and look at them under a magnifying glass. You will see small flat brown bran and small roundish sand looking endosperm. Run this through a stone mill and sieve through the 55 mesh. Stone mill and sieve one more time. Discard the bran. You should have 84% to 88% extraction flour. I have been using about 65% hydration with this flour. It tastes wonderful.

 Greg R

Mebake's picture

Oh, Don't you lure me into another obession, my wife has had enough already with baking alone.. :P

Hehhe... Nice infor there, thanks for answering all my questions..

I shall start with my Hard winter and report with the outcome..


martin's picture

Hi Greg,

 I have recently purchased a Mill that has four output streams. Unbleached, semolina fine, semolina coarse and bran. From your descriptions above these correspond to what you are getting (with the Meadow's Sifter). Do I understand you correctly that you re-grind the two semolina outputs twice more?





ZD's picture

Yes that is how I do it. What brand of mill did you get? Please post with your results.

martin's picture

I purchased a Green mill from Austria. I get 4 streams from the sifter - fine flour, fine semolina, coarse semolina and bran.

I tried to put in a link to the mill but get spam filter problems when try to post. I think google Green Mills Austria should get it.

I remill the fine and coarse semolina and then use the final fine semolina for semolina bread and past. The coarse and the bran go the chickens at the moment. 

 regards Martin Prior

breadbythecreek's picture

Do you add 5% water every day for three days? or just the first day? Do you grind on day four? I'm excited to try this. Sorry if this is a stupid question.

ZD's picture

I estimated my grain moisture to be 10%. I added 5% water on the first day and only the first day to bring it up to 15%. 


breadbythecreek's picture

Thanks for responding.  Do you think this would work with a komo classic?  I'm keeping the temper at 80*F for three days until I grind.  I added 5 g water to 100 g hard red wheat berries.  The grinder is new, so I don't want to wreck it.  Thanks for your advice.

ZD's picture

I don't know that mill or how hard it would be to clean if it glazed the stones. I had a lot of good results when I was doing it but it was a risk. 

breadbythecreek's picture

This website

states that it is easy to clean the stones by putting some brown rice through the mill, and if that doesn't work, cleaning the stones with a stiff brush.  The grains that I've tempered at 5% additional water weight seem very dry after 3 days at 80*F, and they "crack" under a spoon, so I think I'll be giving it a try. Thanks for you input and advice.

Happy baking!

ZD's picture

Let us know how it turns out. 

breadbythecreek's picture

Because my #55 and #30 sieves were delayed in shipping, my grains ended up being held for six days at 80*F. I ground them in my Komo Classic with absolutely no trouble- no glazing, no mess. Somehow I ended up with about 85% extraction.  The bran is very fluffy and the flour is very fine. I'm using it to make a 10% hazelnut meal/60% high extraction/30% AP Flour into a 80% hydration loaf. We'll see.

ElPanadero's picture

Personally I wouldn't put anything remotely moist through my mill, only completely dry grains. Moisture would surely result in particles sticking in the works and that would soon lead to bacterial growth and mould inside. My mill uses corrundum stones though. For those with metal burrs that can be easily dismantled and cleaned, it's probably not a problem. For myself, it's a no no. Shame though as the process sounds interesting.

sourdough chick's picture
sourdough chick

Now that I have been milling and sieving my flour using the Komo Duette and sifter, I have a few questions regarding the extraction of some of the bran.

My whole meal flour is milled at a setting just less than the finest grind. As whole meal flour goes it is perfect. But I have begun to sieve and the bran is (as described above) very fine. I use it to roll the finished loaf in and it is excellent also for putting into my banetton baskets to prevent sticking. One sieving using the finest sieve removes a lot of bran, didn't measure the weight, will think to do that next time. The second sieving on the finest sieve removed a bit more. But the flour is still very dark. I like the idea that perhaps more of the germ is retained but is it?

If someone who has used a Komo (stone) mill - in my case electric - and can confirm that this hydration will assist in the milling without any issues, that would be great. I have no moisture meter either but will try the bite test.

If I understand it correctly, for 1 kg wheat grain I will add 50 gms of water each day?  Just spray this amount of water over as I shake the wheat? Bite test each day? Then mill on fine (not superfine) setting and sieve.

I hope I am doing this right. (I am using locally grown hard red wheat).

antalie25's picture

Hi all,


I would love to try out this tempering method but I am concerned it will damage my mill as it contains corundum stones.


Has anybody tempered grain and ground it in a Hawos mill? If so I would love to hear how it went? 


Thank you.