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< prev - next > Food processing KnO 100641_How to make sausages (Printable PDF)
How to make sausages
Practical Action
stuffed in casings with a diameter exceeding 4.5 cm are often termed ‘salamis’; but actual
salamis are made from coarsely-ground meat and are not smoked. Most types of dry sausages
are cold smoked (12 - 18°C) and in some countries they are heavily spiced with red pepper or
garlic or sometimes hot- smoked and strongly salted (see Technical Brief: Smoked Foods)
before a long period of air-drying. Sausages that are not smoked are known as air-dried
sausages. They have a shrivelled appearance with or without surface mould growth and a
yeasty-cheesy flavour.
Sausage drying rooms should have a fan, and facilities for control of the air temperature and
humidity. The stuffed sausages are hung in a room at 20 - 23°C with an initially high air
humidity (≈98%). In the following 2 - 4 days the humidity must be gradually reduced to below
75 - 80% to remove the surface moisture. They must not dry too fast or the surface will
become hardened and a crust develops under the casing. This prevents moisture loss and the
sausage has an excessively moist centre and the crust will not allow smoke to penetrate.
Neither should they dry too slowly as the surface will become slimy (some producers allow a
white covering of moulds and yeasts on the outside of the cured sausage during drying, which
adds to the flavour). If it is wished to avoid mould growth, the smoked sausages can be rinsed
in hot saturated brine before drying. As a guide, the air humidity should be approximately 4%
lower than the water activity of the product (e.g. if the water activity of the product is 0.96,
the optimum air relative humidity should be about 92%). The properties of dry sausages
depend on both the bacterial fermentation and the changes that take place during a long
drying or ageing process: the total process may require up to 90 days. The final pH of dry
sausages is usually higher than semidry sausages (5.0 - 5.5).
Semidry fermented sausages
Semidry sausages differ from dry sausages by their
‘tangy’ flavour produced by lactic acid accumulation
from the fermentation. They are usually stuffed into
medium- and large-diameter natural or synthetic
casings. Their production time rarely exceeds a few
days. The pH of semidry sausages is between 4.8 and
5.2–5.4 and their moisture content is 35 - 50% (aw
= 0.90 - 0.94). Semidry sausages are often warm-
smoked at temperatures not exceeding 45°C, or
occasionally rising to nearly 60°C for a limited time.
After smoking the sausages are usually air-dried for a
short time in a drying chamber with a relative
humidity at 3 - 5% below the moisture content of the Figure 4: Sausages being cured.
sausage. The bacteria and acid, together with enzymes
released from the minced meat, contribute to the
flavour and colour development and cause the meat
Photo: courtesy of Wikimedia commons at
pieces to soften and bind together in the sausage.
Preservation is due to a number of factors: the antimicrobial action of the salt; up to 2% lactic
acid from the fermentation; reduced moisture content; nitrite-spice mixtures; and
antimicrobial components in smoke when the product is smoked. Examples of semidry
sausages are summer sausages, landjaegar, different types of cervelats, thuringer, metwursts
and Lebanon bologna. For example, landjaegers (or hunter’s sausages) are flattened semi-dry
sausages, made by stuffing a mixture of coarsely ground beef, pork and seasonings into pig or
sheep casings. They are pressed using wooden moulds for 1-2 days at about 20 - 24°C, or 2 -
3 days at 18 - 20°C, which gives sufficient time for the fermentation to take place and to
obtain the required flat shape. The shaped sausages are removed from the moulds, hung from
rods and smoked for 3 - 4 days at 16 - 20°C.