Curing and Smoking Meats for Home Food Preservation
Literature Review and Critical Preservation Points
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6. Critical Preservation Points
These guidelines have been created by the NCHFP using the 2001
Food Code, which are recommendations created by the United States
Public Health Service, Food and Drug Administration (PHS/FDA
2001), and other published science-based recommendations as
referenced. The guidelines have been reviewed by the National Center
for Home Food Preservation’s Advisory Board and external experts.
Adhering to these guidelines will minimize the risk of exposure
to food poisoning organisms.
6.1. General Guidelines
All equipment, work surfaces, and utensils should be cleaned and
sanitized before and after use (PHS/FDA
2001). An example of a sanitizing solution for home use is 1
tablespoon of chlorine bleach in a gallon of warm water (Marchello
and Garden-Robinson 1998). Cross contamination between raw and/or
dirty surfaces with clean or cooked food products should be of prime
During storage or refrigeration, raw products must be separated
from cooked products. Never store raw products above or in contact
with cooked products (PHS/FDA
2001). If necessary, place raw products in pans or utensils
approximately 1-2” deep to keep meat juices from contacting
with other surfaces.
The danger zone for microbial growth is 40-140°F (USDA
FSIS 1997b). Therefore, store, age, cure, or otherwise preserve
meats in a refrigerator below 40°F. Cooking meats to an internal
temperature of 160°F will destroy bacteria that can cause foodborne
illness (USDA FSIS 1997b).
Any recipe that minimizes preservation time within the temperature
danger zone followed by cooking to a safe internal temperature will
minimize risks of food poisoning.
6.2. Curing Guidelines
Meat must be fresh prior to applying any preservation method. Curing
should not be used to salvage meat that has excessive bacterial
growth or spoilage (PHS/FDA
2001). Meat, especially game meat, does not need to be aged,
since curing/smoking will act to tenderize it. If aging is desired,
age all meats below 40°F. (Cutter
Only food grade salt without additives, e.g., iodine, should be
used. Using salt with impurities can produce less desirable results,
especially with fish (Turner,
no date). Thawing must be monitored and controlled to ensure
thoroughness and to prevent temperature abuse. Improperly thawed
meat could cause insufficient cure penetration. Temperature abuse
can allow spoilage or growth of pathogens (PHS/FDA
6.2.3. Curing Compounds
Purchase commercially prepared cure mixes and follow instructions
carefully (PHS/FDA 2001) or blend cure mixes carefully at home using
an accurate scale.
Nitrate. Use cure mixtures that contain nitrate
(e.g., Prague Powder 2, Insta-Cure 2) for dry-cured products that
are not to be cooked, smoked, or refrigerated (PHS/FDA 2001). Dry
cure using 3.5 oz. nitrate per 100 lbs. meat maximum or wet cure
at a maximum of 700 ppm nitrates (9 CFR Cpt 3. 318.7(c)(4), 381.147(d)(4)).
Nitrite. Use cure mixtures that contain nitrite
(e.g., Prague Powder 1, Insta-Cure 1) for all meats that require
cooking, smoking, or canning (PHS/FDA 2001). Dry cure using 1 oz.
nitrite per 100 lbs. meat maximum. For sausages use ¼ oz. per
100 lbs. (Reynolds and Schuler 1982). A 120 ppm concentration is
usually sufficient and is the maximum allowed in bacon (PHS/FDA 2001).
Nitrites are toxic if used in quantities higher than recommended;
therefore caution should be used in their storage and use (PHS/FDA
2001). About 1 g or 14mg/kg body weight sodium nitrite is a
lethal dose to an adult human (USDA
FSIS 1997b). Mistakenly using sodium nitrite instead of NaCl
in typical curing recipes can lead to a lethal dose of nitrite in
the incorrectly cured product (Borchert
and Cassens 1998). For this reason it is safer to purchase and
use curing mixtures rather than pure nitrites (saltpeter).
6.2.4. Cure Penetration
Cure mixtures do not penetrate into frozen meats. Before curing,
it is essential to thaw meats completely first in the refrigerator.
Pieces must be prepared to uniform sizes to ensure uniform cure
penetration. This is extremely critical for dry and immersion curing
(PHS/FDA 2001). Use an approved recipe for determining the exact
amount of curing formulation to be used for a specified weight of
meat or meat mixture (PHS/FDA 2001). All surfaces of meat must be
rotated and rubbed at intervals of sufficient frequency to ensure
cure penetration when a dry curing method is used (PHS/FDA 2001).
Immersion curing requires periodic mixing of the batch to facilitate
uniform curing (PHS/FDA 2001). Curing should be carried out at a
temperature between 35°F and 40°F. The lower temperature
is set for the purpose of ensuring cure penetration and the upper
temperature is set to limit microbial growth (PHS/FDA 2001). Curing
solutions must be discarded unless they remain with the same batch
of product during its entire curing process –because of the
possibility of bacterial growth and cross-contamination, do not
reuse brine (PHS/FDA 2001).
Verify that smokehouses operate as intended (heat, airflow, moisture).
Appropriate calibrated thermometers should be used (for cooking
temperature and meat internal temperature). Procedures for delivering
the appropriate thermal treatment of cooked meats in conformance
with the Food Code must be developed and used. Smoke itself, without
proper cooking, is not an effective food preservative (Hilderbrand
1999). Caution should be used when smoking meats at temperatures
in the danger zone 40-140°F for prolonged periods of time. In
such a case meats must have been salted or cured first.
6.3.1. Smoke Cooking
Consumers should smoke cook foods to internal temperatures as listed
by the USDA (USDA-FSIS 1999).
Table 6.1. Internal Temperatures for Smoke Cooking of Foods (USDA-FSIS
|Ground Meat & Meat Mixtures
|Veal, beef, lamb, pork
|Poultry breasts, roast
|Poultry thighs, wings
|Stuffing (cooked alone or
|Duck & Goose
|Pre-cooked (to reheat)
||Cook until opaque and flakes
easily with a fork.
|Shrimp, lobster, crab
||Should turn red and flesh
should become pearly opaque.
||Should turn milky white
or opaque and firm.
|Clams, mussels, oysters
||Cook until shells open.
Cool cooked products rapidly to below 40°F and keep refrigerated.
Cooked fish products should generally be cooled from to 70°F
or below within 2 hours and to 40°F or below within another
4 hours (US FDA 1998).
Minimize handling of cooked products. Dry (unfermented) products
may not be hot smoked until the curing and drying procedures are
completed. Semi dry fermented sausage must be heated after fermentation
to a time/temperature sufficient to control growth of pathogenic
and spoilage organisms of concern.
Pork products must be treated to destroy Trichinella
by (a) Heat: A minimum internal temperature of 130°F(30 min.),
132°F(15 min.), 134°F(6 min.), or 136°F(3 min.), (b)
Freezing: 5°F(20 days), -10°F(10 days) or -20°F(6 days)
for all pork in pieces not exceeding 6 cu. inches. Double the freezing
times for larger pieces up to 27 inches of thickness or (c) some
combination of curing, drying, and smoking can kill Trichinella,
but these are process specific (9 CFR 318.10).
FSIS approved of the use of up to 50% KCl2 in place
of NaCl for the destruction of trichinae (USDA
FSIS 1995c). Wild game (bear, elk, etc.) must be treated to
destroy Trichinella by heating to 170°F, since some
strains of Trichinella are freeze resistant (CDC
Intentionally under-processed fish (e.g., green herring, or cold
smoked fish) should be frozen first to 4°Ffor 7 days to kill
parasites (PHS/FDA 2001)
or to -10°Ffor at least 7 days (Price
and Tom 1995). Because spores of C. botulinum are known
to be present in the viscera of fish, any fish product that will
be preserved using salt, drying, pickling, or fermentation must
be eviscerated prior to processing. Without evisceration, toxin
formation is possible during the process. Small fish, less than
5 inches (12.7 cm) in length, that are processed in a manner that
prevents toxin formation, and that reach a water phase salt content
of 10%, a water activity of below 0.85, or a pH of 4.6 or less are
exempt from the evisceration requirement (US
FDA 1998). For salted and hot smoked fish, use brine with a
minimum salt concentration of 3.5% water phase salt (Hilderbrand
1999). It is not recommended to hot or cold-smoke fish that
have not been brined (Schafer
6.6. Ham Recommendations
For country ham, dry salt cured ham, country cured shoulder ham,
or dry-cured bacon, the internal salt content should be 4% when
used with nitrates/nitrites or 10% without the use of nitrates/nitrites.
Properly prepared dry cured hams are safe to store at room temperature
(Reynolds et al., In
Press, PHS/FDA 2001).
Soak country cured hams in water in the refrigerator (40°F)
to reduce salt levels prior to eating (PHS/FDA
2001). High humidity during curing and aging may lead to surface
spoilage. Mold may grow on the surface and can be safely washed
All recipes should call for final internal temperatures that will
destroy trichinae. We do not recommend preparing homemade, non-fermented
sausages that are not fully cooked. If you do prepare them, be sure
the meat, especially pork, has been properly frozen to destroy trichinae
and other parasites. Use a meat thermometer to help insure that
meat is kept cold before cooking and that sausage is properly cooked.
Cool the sausage quickly after cooking and keep in the refrigerator
for short term storage or freezer for long term storage (Busboom
1996). Semi-dry cured sausages, such as summer sausage, should
be heat treated to 145°F for 4 minutes to destroy E. coli
that may have survived the curing and fermentation process (USDA
6.8. Storage Guidelines
Store Cured/Smoked Poultry up to two weeks in the refrigerator
or up to one year in the freezer (TAES
Extension Poultry Scientists 1999). Store lightly cured fish
10-14 days in the refrigerator or 2-3 months in the freezer (Luick
1998). Vacuum packaged meats, e.g., smoked fish, must be kept
at 40°F, since the reduced oxygen atmosphere increases the risk
of botulism poisoning (Luick
1998). Modern fish curing/smoking recipes produce a highly perishable
product that rarely keeps better than the raw fish.
6.9. At Risk Consumers
You can protect your unborn child by not eating shark, swordfish,
king mackerel, and tilefish that can contain high levels of methylmercury
(U.S. F.D.A. 2001a).
"At risk" consumers should avoid eating refrigerated smoked
seafood, unless it is in a cooked dish. Refrigerated smoked seafood,
such as salmon, trout, whitefish, cod, tuna, or mackerel, is most
often in recipes for "Nova style, "lox, kippered, smoked
or jerky seafood. These preparations are at risk for Listeria
monocytogenes contamination (U.S.
F.D.A. 2001b). At-risk consumers might want to avoid dry cured
sausages because of the risk of E. coli O157:H7 (USDA
FSIS 1995b). Consumers may want to avoid feeding cured products
containing nitrates/nitrites to babies less than three months old
because of implications in Sudden Infant Death Syndrome (SIDS) due
to nitrate/nitrite poisoning (methemoglobinemia).
Document Use | Preface | Table
of Contents | References