I think you don't very much like to get caught being wrong, again.
Let's stick to the basics and to the facts germane to the discussion and
refrain from left field factoids about refrigerators and the absolute size
of the suspensoid.

specifics below

"Bob (this one)" > wrote in message
...
> Sheldon wrote:
> > hob wrote:
> >
> >> "Bob Simon" > wrote in message
> >> ...
> >>
> >>> I buy the gallon size of milk, split it into two plastic
> >>> half-gallon containers when I get home, and freeze one. After
> >>> thawing for a couple of hours, there is still a block of frozen
> >>> milk in the center. If I use the liquid milk at this time, will
> >>> it be the same concentration as after the whole carton thaws and
> >>> is shaken?
> >>>
> >>
> >> I can't speak from direct experience of personally freezing milk
> >> However, from chemistry, theory says there should be a slight , but
> >> not significant, difference in fat-containing milk, which depends
> >> on the rate of freezing-
>
> No. The explanation here for what milk is has important missing
components.

Missing components? If there are somethings in milk other than solute,
suspended particles, and dissolved stuff, please, tell us.
And none of that "It's so complex, it can't be studied or follow any rules
of science"

Is the 1 micron particle size of butterfat important? (Apparently mom shook
that old milk bottle so hard she turned the fat from your existing 4 micron
globs into 2-3 micron particles but couldn't quite get that last micron,
since it took a day or two for the cream to separate again. And I didn't
realize my eyes were that good.)
By explaining in such detail the size of the particle, are you disputing
the statement that the fat is suspended in the liquid, i.e., an emulsion?

By explaining in great detail how a frost-free refrigerator works
(incorrectly I might add - it sounds far more like a Google answer than a
refrigeration engineer's answer) compared to non-frost-free unit, are you
saying that the rate of refrigeration has nothing to do with how much of the
suspended matter is trapped in the ice-crystal matrix?

>
> >> 1) There are two immisicible liquids in all but skim milks:
> >> fat-based and water-based solutions. The water has dissolved
> >> sugars, etc. The fat has dissolved vitamins, etc.
> >>
> >> 2) Homogenized milk is a suspension of fat solids in water
> >> solution; the fat is not dissolved in the milk. Homogenizing
> >> "breaks" the cold fat into small enough particles that they don't
> >> float in the water solution Think cold butter blasted into such
> >> tiny particles that they remain as solids suspended in the water.
>
> But that's not what milk is. Cold butter blasted into a water-based
> liquid would eventually come out of suspension unless something
> prevented the butter particles from touching and rejoining. That's why
> milk stays homogenized and a vinaigrette doesn't.

And the homogenized salad dressing?

reality is that the smaller the particle, the longer to takes to "cluster"
in a solute. If you get homogenized milk fat small enough to last three
weeks in the cold carton before it noticeably separates, and by then the
milk is either drunk or bad, so who could tell and who would care? Get it
superfine and it will last months in warm ultra-cartons.

>
> >> (since there is no apparent need to homogenize skim milk, is skim
> >> milk homogenized?)
> >
> > Yes, skim milk is homogenized... skim milk is not fat free, it
> > contains about 1% fat.
>
> No. It doesn't. 1% milk has 1% fat. Skim has between 0.1% and a maximum
> of 0.5% fat. And it is homogenized to keep that fat in suspension.
>
> > All that you contributed is correct. Modern
> > homogenizing methods are very through so milk does not readily
> > separate when freezing or thawing, certainly not when using modern
> > frost free freezers and thawing, at least partially, while under
> > refrigeration... anyone still using old fashioned refrigerators
> > should divide milk into smaller containers before freezing, but
> > should do the same with all foods.
>
> This is utter nonsense.

Nonsense? Are you saying that the air (moved by the defrosting fan) does not
remove heat from the surface of the container more rapidly than does natural
convection from still air?
That sure put a hole in my year of thermodynamics and all that convection
theory, and there will be a lot of commercial freezing operations happy to
hear that they can save a lot of money by turning off fans if they follow
your advice.

>Homogenization of milk is not simply a matter of
> making the milk fat particles small. Homogenization is done by forcing
> hot milk through tiny nozzles at high pressure. The fat globules are
> reduced from about 4 micrometers down to about 1 micrometer (millionths
> of a meter). The fat attracts casein protein particles which adhere to
> the fat and create a membrane around each globule which interferes with
> the normal fat clumping.

(Actually less than 1 micron) Which is how homogenized 1% and whole milk
both have the same protein when protein-attracting-fat is removed from one
and not the other?

And BTW,
that arguement makes that 1 micron bit of fat a suspended particle.

It is either dissolved or suspended or solute.

It either floats or it sinks.

And please refrain from telling me that before homogenization, there was a
floating fat layer on the top and sinking protein layer on the bottom of the
glass bottles - and in milk tanks - so they even out in bouyancy with water.
And if that isn't enough, that casein on my cocoa floats, too.

>That's why the fat stays dispersed. Each tiny
> fat globule is surrounded by a membrane that keeps it separated from
> every other one and prevents them from rejoining.
>

The "why" the particle stays small is not germaine to freezing- the
identification as a suspended particle rather than dissolved is.

So we agree that milk is a solute with suspended and dissolved parts.


> Freezers come in two varieties; conventional and frost-free.
> Conventional freezers stay to a very narrow range of temperatures by
> cycling on when the temperature in it drops below the thermostat setting
> by a fixed amount. It turns on the compressor, sucks some heat out of
> the freezer compartment and gets back down below that trigger temperature.
>

> Frost-free freezers have much wider variability for temperatures.

Utter bull.

That would be because the fan moves the air instead of letting it stratify?
How does that "air moving in the freezer making for more variability in
temperature " work?

Take it from someone who designs such systems - the temperature control
is the same for both types. Set point and hysterisis. See the thermostat on
each one's schematic.

The frost-free uses a fan to move air RAPIDLY IN THE FREEZER and enhance
sublimation there, where frost builds up. It also has a bi-metal
sensor/heater ON THE ENCLOSED COOLING COIL which is OUTSIDE THE FREEZER
COMPARTMENT (or behind the panel, if you will), which heats the freezer
coil itself for a very short time once a day, and cuts off the fan when it
does, if there is ice.
And it has features common to that level of appliance - e.g., mullion
heaters in the non-frozen area, which have little to do with defrosting.

>The
> reason that there's no frost in them is because they are designed to
> warm the interior of the freezer compartment to evaporate frost.

No, it's becuase the heater warms the ice-colecting cooling coil metal as
needed (bi-metal), and the cooling coils are not in the freezer compartment,
but rather in a separate compartment. Moving cold air sublimates ice there
and everywhere else- see the ice cube trays in the airflow.

The
> evaporated water is condensed onto a coil that gets heated to make it
> become water which is channeled out of the freezer compartment to an
> evaporator pan where it's heated to evaporate into the room.
>

> Neither kind makes any difference in short-term freezing of anything.

Thus increased convection has no effect on removing heat? You sound like one
of those who think wind has no effect on the rate of heat loss of an engine.

> Over longer periods, the frost-free will cause a great deal more freezer
> burn because of the temperature variations and subsequent moisture
> migration. This is an absolute irrelevancy in the matter of what happens
> to milk when frozen. And Sheldon's prattle is, from the viewpoint of
> physics, absolutely backwards.
>

I think you know little of the freezing process, or else you wouldn't make
such foolish statements.

> > If homogenized milk were prone to
> > separation it would certainly do so while under refrigeration and
> > certainly when left at room temperature, it does not, not to any
> > meaningful degree.
>
> Given that the fat globules are held separate by proteins that aren't
> themselves subject to variations at above-freezing temperatures, this is
> just more Sheldon nonsense. He simply doesn't understand what milk is.
> And is not.
>

That is an unbelievable statement. No variations in an organic molecule at
above-freezing temperatures? An emulsion of a solid in a liquid only
because of proteins? Proteins don't stick together? Emulsions of all other
homogenized substances cannot exist, and all suspensions cannot exist,
without a protective layer on the suspensoid? There goes the year of
chemistry and a whole field of science has to be revamped.
Instead of all those years of school and experience and the accumulateed
scientific knowledge, we could have just googled some prof-pretender with MS
powerpoint.

No, I think you are reaching so you don't have to admit your error.

The graspings of a man who defends his own error only makes himself look a
fool.

----What is in the water component is either dissolved or suspended----.

Don't believe everything you google up or everything you hear.

> > Those who claim their frozen milk separates are
> > doing something incorrectly, or simply lying... old milk that is just
> > beginning to sour will separate much more readily... did I mention
> > LYING.
>
> More Sheldon nasty bullshit from the normal complement of Sheldon
ignorance.
>
> > Btw, human breast milk is frozen all the time (a very common
> > practice), and is not homogenized, leastways not after leaving the
> > breast. hehe
>
> Hehe. He said "breast." hehe... Idiot.
>
> The milk will separate into its fat and cream components. The protein
> matrix has never formed, so can't be broken by freezing.
>
> >> 3) Dissolving compounds in a liquid lowers its freezing point, but
> >> as I remember, adding non-dissolved solids in suspension does not.
> >> The dissolved compounds in the solution do not separate out. They
> >> freeze evenly. (Think salt added to ice-water to make ice cream to
> >> lower the freezing point, and think frozen confections which
> >> freeze with the dissolved sugars evenly distributed.)
>
> Not completely accurate. Look at large blocks of ice made from water
> than hasn't been de-ionized and boiled to remove dissolved gases.
> There's always a cloudy center. Commercial ice makers make clear ice
> from moving water for that reason. Home-made ice cubes will all have a
> cloudy center. It's dissolved minerals and gases, and they've migrated
> to the center.

So milk then would also likewise separate, with the dissolved being more
concentrated in the center. And the original poster should wait until his
milk is all thawed.
Which is not what you have been saying, or is it?

>
> >> I believe
> >> suspended solid particles can be separated out only if the freezing
> >> is done slow enough. Think ore refining to remove impurities, and
> >> slow freezing with ice extraction used to concentrate solids in
> >> suspension.
>
> And think of freeze-distillation of fermented alcohols. The water
> freezes out leaving a more concentrated alcohol behind. It can be done
> several times, each time concentrating the alcohol further until it
> reaches a point where the concentration is so high that it would require
> extraordinary temperatures to do it again.
>

Again, the dissolved in milk then concentrates if you thaw the ice out
first, so the original psoter should wait until it is all thawed.

> >> 4) Liquids frozen in a container do not freeze all at once
> >> (supernatant excluded). There are two conditions of freezing: rapid
> >> freezing, where the water crystals in contact with the much-colder
> >> sides form first and cool so rapidly they cannot migrate to the top
> >> of the solution, and they grow small crystals from the sides,
> >> expanding into the rest of the solution, trapping most of the
> >> suspended particles in the crystal matrix; and slow freezing, where
> >> the water cools and expands and floats to form large-ice-crystal
> >> ice on top, ice unable to trap the suspended solids until the
> >> convection slows.
>
> This doesn't take into account the nature of milk as described above.
> Freezing will disrupt the protein matrix surrounding each fat globule so
> that upon thawing, the fat will clump.

assuming it 1) it can clump that fast, and 2) the protein theory exists and
has merit

The protein will, as well, and
> change the mouthfeel. Agitation can help to redistribute the fat, but
> not to the condition before freezing.
>
> >> Theoretically - The water and water-soluble solids should freeze at
> >> one temp, lower than that of water.
> >>
> >> If you freeze the milk and suspended fats fast enough, it shouldn't
> >> separate.
> >>
> >> If you freeze it slow enough , the concentration of suspended
> >> particles will vary, by location, in the container.
> >>
> >> theoretically.....
>
> And a very nice theory it is. Except for the chemistry and physics of
> milk, it's lovely. The complexity of milk, however, removes it from this
> view.

If your hypothesis were true, then basic and organic chemistry laws have
been debunked.

Since they have not, a reasonable man assumes you are incorrect in your
assumptions, and your hypothesis is incorrect.

>
> I suggest reading "On Food and Cooking" revised 2004 for a much longer
> and scientifically clear discussion of milk and everything about it.
> Harold McGee is one of my heroes. Good science and good writing.
>
He's a hack who I have read, and who needs some peer review of his hackneyed
pop theories - as I noted in earlier posts.

> Pastorio
>
> > ---------
> >>
> >> Note - due to the expansion of water as it becomes a solid, and
> >> that it takes time-in-liquid to create large ice crystals, cells
> >> containing water and molecules which attach to the ice crytal
> >> lattice are not damaged by very rapid freezing, but they will be
> >> damaged by slow freezing due to the large crystal formation. That
> >> suggests that taste may be affected by slow freezing.
> >>
> >>> -- Bob Simon remove both "x"s from domain for private replies
> >
> >