Freezer Storage of Meat

frozrn meat

Proven/best practices freezing is an important part of both modern meat processing and consumerism, but I still had a hard time getting motivated to write a blog post about it.  This subject is almost as exciting as watching meat freeze.  While freezing is indeed a boring and simple natural process, it does afford consumers the ability to greatly prolong the amount of time in which they can enjoy consuming a surplus of otherwise highly perishable meat products.  Freezing also provides the convenience of having high quality protein on-hand, can aid in the more uniform slicing of partially frozen meats and will save consumers money if they buy wholesale cases of cuts such as Choice chuck rolls; then work them into raw retail size cuts and/or value-added precooked products.  From time to time throughout the year I make batches of minimally processed, high quality meat items, on weekends, then conveniently enjoy them throughout the following months until they are gone.

At the retail level, freezing meat can me used to store seasonal market surpluses while some cuts are at a comparatively low cost per pound.  Example: In many Northern parts of the U.S. the popular outdoor cooking of pork ribs declines drastically during the winter months; all while a steady supply of hogs continues to be marketed.  During such times the economic law of Supply and Demand drives the price of ribs low enough for retailers to freezer store them to meet summer demand; at about the same retail price they charge year round.  The retail offering of other previously frozen raw meat cuts is only practiced to a limited extent due to consumer acceptance issues, plus boxed beef wet-ages under refrigeration during distribution and marketing.  Most broiler and fryer chickens are sold fresh in order to avoid bone darkening that occurs when young birds are thawed.  According to FSIS regulations:  Chicken that was ever below 26F internal temperature cannot be labeled as “Fresh.”

The freezing of red meat roasts and trimmings is often practiced in the further processing segment of the industry.  However, if a carcass is frozen before the onset of rigor-mortis, the resulting meat will be very tough (Cold Shortening).  Each year freezer cargo ships bring the U.S. untold tons of grass-finished boneless beef to grind & blend with domestic fat-cattle trimmings; to produce institutional and retail frozen precooked products.  Domestic fat trimmings are also sometimes frozen.  Fresh pork leg (hams) are freezer stockpiled for the Christmas and Easter busy seasons.  Fresh vacuum packed whole briskets are sometimes frozen to process into wet-packed corned beef (good water money) during the weeks leading up to Saint Patrick’s Day.  Coarse ground beef and boneless pork picnics bought up by the USDA to stabilize meat prices are frozen prior to being further processed for eligible recipient agencies.  Freezing can also be used to produce “Certified Pork” that is held below 0F long enough to assure the destruction of Trichinella spiralis, the muscle worm that could possibly be in hogs and bears that are allowed to root in the ground.  Extended freezing will kill some parasites and bacteria, but others merely go dormant and can grow again if they encounter a favorable temperature upon thawing.

Microwaves equipped with moving belts is used to quickly temper-out frozen meat in some further processing operations.  Microwave tempered meat blocks have less microbial growth than those slow thawed under refrigeration.  Vacuum packed roasts can be thawed fairly rapidly by placing them in vats of cold water that have air pumped in through perforated metal pipes.  Such pipes are small in diameter and are attached to a flexible air hose for ease of movement in and out of the vats.  I apologize in advance, but I just have to tell my freezer-rat story:  About 25 years ago I was at a plant that used various off-site freezer storage facilities to hold wholesale cartons of Choice briskets.  One of those freezer warehouses apparently lacked good rodent control because our plant received frozen boxed briskets that had a few rats living in them.  The rats were eating frozen meat and making warm nest out of shredded vacuum bags and cardboard.  They must have either been eating ice or getting enough moisture out of the meat to sustain themselves.  Needless to say, all hell broke loose and the freezer warehouse in question was shutdown.

Best practices:

Remove bones to save on freezer space and to help prevent the puncturing of packaging materials.

Trim excess subcutaneous and seam fat.  Thick fat is not normally eaten, so removing it makes more room in the freezer and meat should freeze quicker.  Fat oxidation can lead to rancid off-flavors which can taint abutting meat.  Harder (more saturated) fats do better in freezer storage because oxidative rancidity develops slower.  Lean ground products have a longer, high quality freezer storage life.  Salt in sausage products etc. increases the rate of fat oxidation.  Aging meat prior to freezing also lowers the length of freezer shelf-life by causing faster fat oxidation.

Tightly packaging meat for freezer storage reduces oxygen uptake in fat and the dehydration of meat surfaces.  Freezer burn is defined as the browned/oxidized surface of long held and/or poorly wrapped frozen meat.  Colder storage temperatures increasingly slow the development of freezer burn.  Always store meat at least below 0F.  Tight double packaging in zip-lock bags does an adequate job at minimal expense.  Don’t hold meat in freezer storage longer than recommended: click here.

frozen packs

Rapidly freezing reduces meat cell rupture that affects thawing purge/drip loss/weep and product texture.  The faster the freeze, the smaller the ice crystals formed.  I don’t pour bag purge back into ground meat because I perceive that it may contain a concentration of film packaging residue; especially from slicing open vacuum bgs.  I was once told by an Horticulture Vegetable Canning professor that all packaging materials except glass react with their contents (glass is chemically inert).  Spread products in a single layer and set the freezer on its lowest setting.  Refreezing properly handled meat once or twice does not materially affect meat quality, but there will be more product drip loss each time.  Meat minerals and vitamins are unaffected by proper freezing and thawing.

Frozen meat will have a slightly higher cooking loss than fresh meat.  A roast can be cooked from the frozen state, but it will take about a third longer to cook at the same temperature.

Fun fact:  Due to the minerals naturally present in red meat, it freezes at 28F.  The addition of salt etc. will cause meat and meat products to start freezing at slightly lower temperatures.

 

Written by George Wolfer

George Wolfer

Been associated with the meat industry pretty much since starting at a Vocational High school Meat Processing program in 1974. Like to learn and teach interesting and worthwhile livestock production, meat processing and marketing practices.

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