Lightest, tastiest crust yet

[November]

Peter,

It isn't safe to say that a more finely milled flour will hydrate more fully if unsifted, compared to other flours.  It would only be safe to say that a more finely milled flour will hydrate more fully if sifted.  As a matter of fact, a more finely milled flour has the potential for more clumping than a flour with larger particles, because the attracting forces between the particles is in greater proportion to the particle mass.  It's one of the reasons why you can make a jar out of wet clay and not wet sand.

Someone may end up getting a perfectly fresh, clumpless bag of flour and there will be little to no difference, but that's an ideal situation that rarely happens.

- red.november

[scpizza]

My recollection is that you have a Santos mixer, which appears to be superior to just about any other mixer that might be used in a home setting. Is your conclusion as to that mixer only, or any mixer? Also, were your tests limited to 00 flours?

Peter, yes I am using a Santos.  I presume you are wondering if sifting may make up for inadequacies of home mixers and thus be a useful technique in a home setting.  Can't answer that as I don't have any home mixers to test with.  Test was done with Caputo 00 Pizzeria.

[scpizza]

Which is fully what I would expect.  It's wetter because at the end of mixing, there's more water in the dough.  Water that is not immediately absorbed into the flour will evaporate more rapidly during mixing/kneeding.  You should be able to detect a difference in weight at the end of mixing/kneeding.  If you don't, the detection of one dough being wetter is a sensory illusion.

Seems like November and I are frequently hypothesizing the underlying physics of pizzamaking a little differently and this is no exception.

I spend more time mixing the sifted dough because of the extra time it takes me to slowly sift the flour in.  Thus that wet batter is exposed to the air longer and if anything more of the water should evaporate from the sifted batch.  Thus I would argue even if evaporation plays a role, the sifted batch should feel drier in the end.

I'm skeptical evaporation from the mixing bowl plays a significant factor, given the air exposure time is low, on the order of 15 minutes.  I need to run an experiment where I simply stir a bowl of water for 15 minutes and see how much is lost to evaporation.

The original hypothesis was that sifted dough would feel drier than non-sifted at the exact same hydration level because the water would be more evenly dispersed within the matrix of flour compounds and more effectively bound to them so as to be less available to cause stickiness when handled.

[November]

Thus that wet batter is exposed to the air longer and if anything more of the water should evaporate from the sifted batch.

Just as I'll explain below, this wetter stage of the batter doesn't create as much friction as the dryer stage, and even more consequential, the wetter stage does not have as much surface area from which to evaporate water from.  Exactly how long does it take you to sift flour anyway?  It only adds a few seconds to my dough preparation time.

Thus I would argue even if evaporation plays a role, the sifted batch should feel drier in the end.

And yet it doesn't.

I need to run an experiment where I simply stir a bowl of water for 15 minutes and see how much is lost to evaporation.

This won't simulate anything of value.  Churning water does not create much friction, and more importantly, it does not create a significant amount more of surface area.

- red.november

[November]

The original hypothesis was that sifted dough would feel drier than non-sifted at the exact same hydration level because the water would be more evenly dispersed within the matrix of flour compounds and more effectively bound to them so as to be less available to cause stickiness when handled.

I guess I should ask what your new hypothesis is, since this one didn't work out.

- red.november

[scpizza]

It takes me so long to sift because of the extremely fine mesh of the sieve I must repeatedly bang with the heel of my hand to get the flour to fall through.  Maybe I could pre-sift into a bowl and then just dump the bowl in, but I fear post-sift clumping.  I prefer sifting directly into the bowl of water to immediately immerse the fine "mist" of flour directly into the water.

I don't have a good explanation for why sifted dough feels wetter, I wish I did.

So mixing drier dough may cause it to lose moisture faster than mixing wetter dough due to increased heating from higher friction and the increased surface area of "rougher" surfaces?  Very interesting if true - counterintuitive that the more water you add to the dough, the less you loose from evaporation.  Need a good experimental design to test this.

How about I make two 2kg batches of dough, one at 50% hydration and one at 70% hydration.  Mix both for 30 minutes.  Carefully weigh the mixing bowl for each, before and after the mix using my +/- 0.1g scale.  Key question in my mind is would I observe any weight loss due to evaporation at all and if so, which one would be greater.

[Jack]

It takes me so long to sift because of the extremely fine mesh of the sieve I must repeatedly bang with the heel of my hand to get the flour to fall through.  Maybe I could pre-sift into a bowl and then just dump the bowl in, but I fear post-sift clumping.  I prefer sifting directly into the bowl of water to immediately immerse the fine "mist" of flour directly into the water.

I sift into a bowl and spoon the flour into the mixer.  I doubt you will have much post-sift clumping, as I don't with any of the three fours I use.

Jack

[November]

So mixing drier dough may cause it to lose moisture faster than mixing wetter dough due to increased heating from higher friction and the increased surface area of "rougher" surfaces?

This is not speculation or theory, so there's no "may" about it.  Wetter dough will have less surface area, and drier dough will have more friction.  The laws of physics haven't changed on us.  Mixing drier dough requires more work (energy).  More work translates to more entropy (heat).  Drier dough is less dense dough (as a whole).  Denser objects of same mass have less surface area.  These are inescapable principles.

The only thing that could be in question is if the sifted dough you handled was truly wetter.  I don't know how long you waited before mixing the second batch, but an error from having higher residual heat from the first batch might have contributed to a higher evaporation rate in the second batch.  There might have been an error in measuring.  There might have been a change in humidity in the kitchen because of the evaporation of water in your work environment from the first batch (e.g. formula water, source water, moisture from your body {e.g. skin, breath}) which would lower the evaporation rate of the second batch.  There are all kinds of conditions like these that might have changed between the first batch and the second.  If I were to assume you accounted for everything, then I would also assume you would have mentioned even one of them as an alternative explanation for the higher wetness if the error was present.  Since you didn't, I have no choice but to believe that if one was wetter than the other, it was because of the aforementioned principles.

counterintuitive that the more water you add to the dough, the less you loose from evaporation.  Need a good experimental design to test this.

I don't see what's counterintuitive about it.  As I described above, when you add water up to the absorption level of the flour, you increase the dough's density.  For density to increase one of two things, or both, have to happen.  The volume has to decrease with the same amount of mass, or the mass has to increase with the same amount of volume.  In the case of dough where the flour is absorbing water, you are doing both.  However, to address the wording of your statement specifically, I'm not talking about adding more water, I'm talking about more water being trapped in the dough.  There's a big difference.  If you just keep adding more water, you'll have more water to evaporate.  We were talking about sifting versus not sifting, not 50% hydration versus 70% hydration.  You can perform that experiment if you want, but it won't prove anything about sifting versus not sifting.  If you do perform that experiment, you'll have to take into consideration at least all the things I mentioned in the previous paragraph.

In my case, I already know that by sifting the flour I use, using the sieve I own, the nominal surface area of the flour increases by 11.626%, and that includes sifting into a container to be transfered into the mixing bowl.

- red.november

[scpizza]

This is not speculation or theory, so there's no "may" about it.

Citing a set of indisputable physical principles does not prove those principles are the primary factors determining perceived dough wetness in the sifted vs. non-sifted question.

Pizzamaking relies on a large, complex body of physical principles many of which act in opposition to each other.  I could cite a different set of equally indisputable physical principles suggesting sifted flour should produce dough that handles drier.  It's not the validity of the principles that is in question, it's the link to perceived dough wetness.  That link is very much unclear.

When the (valid) surface area / heat evaporation principle is suggested as the dominant factor determining dough wetness in the sifted vs non-sifted trial, it would be incautious to accept that explanation a priori simply because the underlying physical principles are valid.  Instead, one should design and execute experiments to yield direct insight into if those principles really are a significant factor and if they really are what is causing sifted dough to handle wetter.  Nothing speaks like empirical data.

If I were to assume you accounted for everything, then I would also assume you would have mentioned even one of them as an alternative explanation for the higher wetness if the error was present.

Multiple trials of sifted vs. non-sifted under even more tightly controlled conditions would be ideal to help reduce the possibility of extraneous factors like ambient humidity variations and water temperature differences influencing the results.  But alas, there is only so much time in the day for the pizzamaking hobby.  One does the best one can to eliminate such variables but experimental error is always a concern.

[November]

I could cite a different set of equally indisputable physical principles suggesting sifted flour should produce dough that handles drier.

Go ahead.

[November]

It's not the validity of the principles that is in question, it's the link to perceived dough wetness.

This is just doubletalk.  To say there isn't a link between cited principles and dough wetness in general is to deny that the principles are valid.  What I hope you mean is that you don't have enough evidence to establish a link between these principles and your dough wetness.  If that's all you're having a problem with, reread my post where I stated all the conditions that could lead to errors.  The bottom line is if a dough is wetter, it has more water.  I have no idea why you would try to dispute that.  If you want to try your hand at an explanation that doesn't include "more water equals wetter dough," and don't want to admit to an error in your measuring or condition allowances, I'm ready to hear it.

Science exists to explain the phenomena behind our observations.  It isn't a medium for floating ideas about what didn't happen.

- red.november

[scpizza]

Go ahead.

Sure.  One word:  Hysteresis.

From Wikipedia (emphasis mine):

Matric potential hysteresis
“The relationship between matric water potential and water content is the basis of the water retention curve. Matric potential measurements (Ψm) are converted to volumetric water content (θ) measurements based on a site or soil specific calibration curve. Hysteresis is a source of water content measurement error. Matric potential hysteresis arises from differences in wetting behaviour causing dry medium to re-wet; that is, it depends on the saturation history of the porous medium. Hysteretic behaviour means that, for example, at a matric potential (Ψm) of 5kPa, the volumetric water content (θ) of a fine sandy soil matrix could be anything between 8% to 25%.”

Translation to pizzamaking: based on the saturation history of flour, the actual water content of partially saturated flour can vary by double digit percentages from the water content as measured at the surface (i.e. stickyness).  Based on the basic physical principle of the hysteretic effect (simplified: memory effect) exhibited by water filling and draining the pores of flour particles it follows that a saturation history profile of more complete surface area exposure to water from contact with sifted flour is more likely to result in an apparently dryer dough that nonetheless contains the same amount of water by volume as a non-sifted dough.

This principle is just as valid as but produces an opposite outcome than the "reduced evaporation" principle offered heretofore.  Am I certain hysteresis trumps "reduced evaporation?"  Absolutely not.  Am I certain "reduced evaporation" trumps hysteresis?  Absolutely not.  Both are equally plausible as dominant factors influencing perceived wetness of sifted versus non-sifted flour.  Further experimentation is required to ascertain which, if either, explanation among multiple possible explanations, is dominating.

[November]

Matric potential hysteresis?  Are you kidding me?!  To argue the point you fabricate a correlation to matriculation?  When did a saturating amount of water pass through your flour before you used it, and how did you manage to use some flour exposed to it with one batch and not the other?  Are you suggesting that it was possible the water saturated the flour and leaped back out of the mixing bowl before you added it again?

How do you expect people to take you seriously with stuff like that?

- red.november

[scpizza]

Fabricating?  I'm citing proven scientific principles of water absorption into granular, porous materials.  Nothing in this area requires 100% saturation to occur first to render the principles pertinent.  I'm surprised you summarily dismiss these principles of absorption as inapplicable to water absorbing into flour.

If any models are to be critiqued, I would be inclined to critique the marble-in-a-jar model as an overly simplistic representation of the dynamics of water absorbing into porous flour particles amidst forming semi-permeable sheets of gluten.

We could endlessly debate theories with each of us saying "My theory is mas macho than your theory" etc.  But I really don't see that abstract debate as helping to uncover the truth about sifting.

I reiterate my belief in empirical results.  I intend to test your theory of evaporation because I'm curious if it indeed is correct or not and a true factor in using sifted flour versus not.  I'll post the results.

Given your degree of certainty that your theory is the applicable one here, I'm sure you warmly welcome my test and these results because they will most certainly demonstrate your theory is accurate, no?

[November]

Fabricating?  I'm citing proven scientific principles of water absorption into granular, porous materials.  Nothing in this area requires 100% saturation to occur first to render the principles pertinent.

Yes, fabricating.  It requires saturation, period.  Unless you are pre-wetting your flour, this effect you're trying to pass off as a possibility is fantasy.  You are literally suggesting that the sifted flour was exposed to "filling and draining" prior to its use in your dough.  Either you don't fully understand the effect, or you're intentionally insulting my intelligence.

I'm surprised you summarily dismiss these principles of absorption as inapplicable to water absorbing into flour.

I summarily dismiss it because I understand it.  For water potential to change in a system due to hysteresis, water must first be introduced to the system.  Sifted versus non-sifted flour has nothing to do with it.  You can't have intermolecular forces "remember" something that hasn't happened yet.  Once the flour meets the water, sifted or non-sifted, the water is absorbed at whatever rate that may be for each, and that's the end of it.  No memory effect.  No hysteresis.

If any models are to be critiqued, I would be inclined to critique the marble-in-a-jar model as an overly simplistic representation of the dynamics of water absorbing into porous flour particles amidst forming semi-permeable sheets of gluten.

You have been inclined so far to critique every model, because you seem to be in constant want of a different explanation than the one offered to you.  I gave the explanation I did because I know it to be accurate while still conveying the principles in a way most people can understand.  I'm not here to try to impress and confound people.

And in the spirit of making things simple, to those reading this thread that are confused by matric potential hysteresis, all it represents is the difference in the amount of energy required to move water out of a system than it took to move it into the system.  But obviously, this is not about moving water in and out of flour.

Given your degree of certainty that your theory is the applicable one here, I'm sure you warmly welcome my test and these results because they will most certainly demonstrate your theory is accurate, no?

I'm not going to lie and say I wouldn't be skeptical about your results, even if they confirmed what I described.  Your entertainment of the notion of hysteresis doesn't exactly instill confidence.  I'm not going to try to stop you from any testing you want to do.  It's your right to do whatever you want to do (legally) with your time.

- red.november

[abatardi]

Rulers, anyone?

- aba

[scpizza]

Rulers, anyone?

I'll be needing the yardstick.

Just kidding!!!!!!!!   

[November]

scpizza,

Since this site is about sharing information, I would like to propose that you share with us how one would go about testing for matric potential hysteresis in flour.  I'm sure it would go a long way to resolving this debate, and giving the credit you deserve for coming up with this idea.  Then, to be most helpful, you could test your sifted and non-sifted flour for matric potential hysteresis.  I really wouldn't want you to waste time on my ideas before you've had a chance to test yours.  Please report back with your results at your earliest convenience.

- red.november

[scpizza]

Since this site is about sharing information, I would like to propose that you share with us how one would go about testing for matric potential hysteresis in flour.  I'm sure it would go a long way to resolving this debate, and giving the credit you deserve for coming up with this idea.

Unfortunately, I've not the equipment nor the expertise in absorption science to test it.  Nor do I claim with any confidence its effects are significant, only that they are plausibly pertinent.  I only offer it in response to your request for an illustration of an alternative relevant physical principle, other than your evaporative principles, worthy of evaluation for potential effects in understanding sifted vs. non-sifted flour characteristics.

Instead of the example of matric potential hysteresis, I could also offer a less esoteric counter-example.  Actually I am intuitively fond of the model that says the sifted flour should be drier because the sifted flour having absorbed more water has more successfully trapped that water in internal flour particle crevices, pores, and chemical bonds.  This bound up water should be less available to produce surface stickiness (note: I am imagining surface stickiness as caused by "free water" - maybe a flaw in my model?)

But please let's not continue the theoretical back-and-forth.  Instead let's work together to design interesting, creative experiments that give us useful data that enables us to actually observe what's going on to confirm or disprove whatever hypotheses we may have.

[scpizza]

Below are my test results.  Testing the extreme endpoints of 70% and 50% hydration mixing for an excessively long 20 minutes I measured a 0.2g weight difference per dough ball.

This does lend support to the notion of increased evaporation from stiffer dough.  However the difference is extraordinarily slight.

To give some perspective note that to move from 60% hydration to 61% hydration in a 250g dough ball one must add approximately 3g of water.  Also note that the frictional difference from using sifted flour versus unsifted flour in identically hydrated dough will be at least an order of magnitude more slight than the frictional difference between 70% and 50% hydrated dough.

Thus I conclude that evaporative loss differences between sifted and non-sifted doughs are too negligible to play a meaningful role in affecting a perceived wetness difference.