The informal experiment done by someone here in Norway some years back (not
published except in an anecdotal report in the BF mothers' org newsletter)
on a very few samples of breastmilk frozen directly after expressing, to see
whether there was a difference in bacteria counts in milk dependent on
method of thawing (standing on counter at room temp, thawing in a warm water
bath, or microwaving) included tests of milk that was thawed by all those
methods, re-frozen, and thawed again.  The only parameter they examined was
bacteria counts.

They found that even after thawing and re-freezing and re-thawing, the milk
was not appreciably affected with regard to inhibition of bacteria growth as
long as it had not been microwaved.  Microwaving frozen milk to serving
temperature rendered it incapable of preventing bacterial growth; the sample
that was exposed to heating by microwave had bacterial growth similar to
breastmilk substitutes.  Please note that breastmilk substitutes must be
used fresh, always, and can not be re-warmed and certainly not frozen and
thawed, ever.

If milk has even been scalded before freezing, the anti-immune properties
that prevent growth of bacteria will have been weakened or destroyed. I
would not advise even re-using, not to mention re-freezing breastmilk that
had been pasteurized or even just scalded.  Such milk is as perishable as
breastmilk substitutes are.  The less processed it is before being frozen,
the more anti-infective qualities have been preserved.  Freshly expressed
milk that has been refrigerated and then re-warmed to serving temperature
can, it seems, be safely stored in the fridge and re-warmed later if the
child leaves some after a feed.

This means that mothers whose milk goes rancid if they don't scald it before
freezing should probably discard whatever is unused after thawing. One way
to minimize waste is to freeze in small portions so that there is less risk
of thawing out more than the baby will take at a feed.  Small portions are
also quick to thaw if more is needed. 

Rachel Myr
Kristiansand, Norway

             ***********************************************

Archives: http://community.lsoft.com/archives/LACTNET.html
To reach list owners: [log in to unmask]
Mail all list management commands to: [log in to unmask]
COMMANDS:
1. To temporarily stop your subscription write in the body of an email: set lactnet nomail
2. To start it again: set lactnet mail
3. To unsubscribe: unsubscribe lactnet
4. To get a comprehensive list of rules and directions: get lactnet welcome