The Fresh Loaf

News & Information for Amateur Bakers and Artisan Bread Enthusiasts

Home Stonegrinding

PeteBlenk's picture
PeteBlenk

Home Stonegrinding

Hi,


I recently bought a home stonegrinder in order to max out on the health aspects that come with baking whole-grain breads. I have a couple of questions with which I would appreciate some help.


1) When grinding, should one let the stones touch each other? At this stage I am quite scared of damaging the stones, but i am finding that if the stones have fairly reasonable (i.e not terribly light) contact with each other, I get a very nice medium coarseness


2) Should one partially grind the grain to a coarse grind and then go fine, or should one just go straight for fine? I tried the two step process and found that the flour didn't come out a whole lot finer whilst the bran stayed exactly as is. If the two stage process is better, how coarse should the first grind be?


3) Whilst I understand that the friction will raise the temperature of the flour, what is an acceptable temperature for the flour to come out?


4) What are the signs of a good quality grind, and what are the indicators for having messed it up?


 


Thanks a lot,


Peter.

charbono's picture
charbono

1. Don’t let the stones touch. It wears the stone, heats the flour, and imparts grit. 2. With a good mill, you should be able to get fairly fine wheat flour in one pass. If you find that fine flour is not possible without heat and slow production, back off to a coarser setting that breaks all the grain and proceeds rapidly. Instead of putting all the flour through a second pass, sift it with a sieve or strainer. Then run only the coarser material though a second pass on a finer setting. 3. Flour temperature depends on the type of mill, the setting, and the grain. 100°F flour is as hot as I’ve measured with my Retsel Mil-Rite. What mill do you have?

PeteBlenk's picture
PeteBlenk

Hi, and thanks a lot.


My mill is a small Osttiroler Getreidemuhlen, which, by all accounts is a really reputable mill from Austria. The temperature attained is c.91F.


When you sieve prior to the second pass through, do you sieve it very fine, or to a medium whole wheat grind? Alternatively put, is there a minimum size residual that should pass through, or is any size OK, as long as it didn't pass through your fit for purpose flour?


What sort of ratio of flour to bran do you manage to extract? Using the technique of sieving and regrinding, I managed to get ratio of 64% bran to 36% bread flour by weight. Seems a bit meagre on the flour, but I would not know.


Cheers.

charbono's picture
charbono

After one pass on a fine setting with my mill, about 5% of hard wheat is retained on a #20 (.84 micron) sieve. #20 is not very fine, but most of the flour that passes is much smaller.

If I had a mill that was producing coarse flour, I wouldn’t spend a whole lot of time sifting fine flour. After the first pass on a wide setting, I’d probably sift through a coarser sieve (perhaps #14 or #16), re-mill the retained material on a fine setting, and be done with it.

PeteBlenk's picture
PeteBlenk

Thanks a lot for this. I sort of got to that point as well when I started getting irritated with my finer sieve.


Do any of you ever get some white stuff left on the bran (which I assume is endosperm) which you can't get off regardless of how many times you do pass it through? I have this with wheat from one supplier (a darkish wheat) but not from the other. Could this be a sign of the quality of the wheat?


Cheers, Peter.

charbono's picture
charbono

I haven't noticed much clinging endosperm.  From what I've read and seen, the "bran portion" of soft wheat is larger than hard wheat.  The amount of separable bran will also vary depending on the moisture level of the grain.


 

charbono's picture
charbono

#20 sieve has .84 mm openings.


 

charbono's picture
charbono

I’d like to re-visit the issue of the touching stones.

In the case of natural stone mills such as the Meadows, one finds a position at which they are definitely not touching, with the machine on, before introducing grain. With man-made stones, the issue may not be so clear. My mill instructions do not contain a prohibition of touching stones (except they have to be loose enough to let flour out). I don’t adjust the stones to a fine setting by sight; I do it by feel. With the machine off, I tighten the knob to the point of slight resistance, and then back off slightly. At that point, I think they are still slightly touching. However, the machine is turned on with a loaded hopper, and in about one second there is grain holding the stones apart.

When reading about natural stone mills, one soon reads of the need for re-sharpening. With man-made stones, the issue doesn’t seem to come up.

PeteBlenk's picture
PeteBlenk

Thanks for this.


The manual indicates that my stones are self-sharpening and are guaranteed for 10 years (a black granite from Czech Republic, for what that's worth). I have not noticed any grit in the meal, so I assume it's OK that they touch.


I loosen the wheels after every grind. At the start I switch the machine on and adjust until they just touch, switch off and fill the hopper and then re-turn on. My sense was also that the wheat keeps it apart after that as if it was too tight, the wheat would either come out at a much higher temperature or it would simply not be able to turn.


Your comments on the bran make sense. Nonetheless I feel quite cheated at only being able to extract 36% of final weight as fine flour. I guess that the flip side of that is that with my wholegrain, I will never develop stomach cancer!!! Way too much roughage.


As a matter of interest, do you know what size sieve would yield white bread flour, what would yield whole wheat flour and what would yield cake/pastry flour?


I will actually try to get into contact with the manufacturer and let you know the outcome of these same questions as I would be interested in seeing their take on it.


Cheers, and thanks so much for your help.

charbono's picture
charbono

In the U.S., commercial white flour must have a pass rate of 98% through a #70 (.21mm) sieve.  As near as I can tell, cake and pastry flours are further distinguished by protein and ash level.  Whole wheat has a much looser spec, with at least 50% passing a #20 (.84mm) sieve.


 


 

PeteBlenk's picture
PeteBlenk

Thank you so much for your feedback. It has been extremely helpful.


I have put a mail out to the manufactrer and will feed back on their reply when I get it.


Cheers.