Churning of butter is the process of agitating cream or milk to separated the fat globules from the liquid .
Theories of churning.
advantage and disadvantage of churning of butter .
CIP unit in butter churning unit
process of churnig of butter
history
Factors influencing churnability
2. Butter churn
Theories of churning
Factors influencing churnability
Churning of butter
Mechanism of butter churn
Some butter churn machins
Continuous churning machine
Advantage of churning
Disadvantage of churning
CIP(
index
3. STUDY OF BUTTER CHURN
Churning of butter is the process of
agitating cream or milk to separated the fat
globules from the liquid .
This traditional method has been used for
centuries to make butter at home or on farm
5. Fisher and Hooker’s phase reversal theory
This theory was proposed by Fischer and Hooker in 1927, the
theory is therefore also referred as Fischer and Hooker’s theory
According to this theory,churning is a process of phase reversal, i.e.
changing an oil-in-water type emulsion (such as cream) to a water-in-oil
type emulsion (such as butter).Agitation of cream in the churning process
causes coalescence and clumping of fat globules until eventually the ratio
of the surface area to the volume of fat units becomes so small that it can
no longer contain all the buttermilk in stable form. The fat-in-water
emulsion then suddenly breaks, yielding butter grains (consisting of an
emulsion of water-in-butter-fat) and free buttermilk.But this theory fails to
explain the results of microscopic studies, which reveal that a proportion
of fat globules in butter are still intact in the worked butter.Hence butter is
not a true water-in-fat emulsion whereas this theory assumes that butter is a
water-in-oil type of emulsion.
6. Rahn’s Foam theory
According to this theory, the presence of foam/froth is essential for
churning. It also postulates that there is a ‘foam-producing’ substance
present in cream (and milk) and which gradually solidifies as the cream
or milk is agitated. Foam is created during the churning period. The fat
globules, due to surface tension effects, tend to concentrate and clump
on the foam bubbles.The foam-producing substance assumes a solid
character and causes the foam to collapse. The fat globules then
coalesce and butter is formed.This theory also fails to explain
continuous butter-making processes where in some cases foam
formation (i.e. the presence of air) is not required. This theory
assumes that the presence of foam is essential for churning.
7. King’s Modern Theory.
According to this theory, the true explanation of what takes place during
churning appears to lie midway between the first two theories. The current
concept of mechanism of the churning process may be summarized as follows:
In cooled cream at churning temperature, the fat is present as clusters(clumps) of fat
globules and within each globule it is present partly in solid and partly in liquid form.
Churning breaks up the clusters and causes foam/froth formation. The globules
become concentrated to some extent in the film around the air bubbles in the foam
and are thus brought into close contact with each other.
The movement of the globules over one another in the foam film and the direct
concussion between them causes a gradual wearing away of the emulsion-protecting
surface layer of the phospholipids-protein complex. The globules then adhere
together to form larger and larger particles.
8. Eventually these particles become visible as butter grains (granules). As the granules form,
they enclose some of the air from the foam. The fat in the granules is still mainly in globular
form.
The working of butter grains causes the globules to move over one another.Under
the effect of friction and pressure, some of them yield up a portion of the liquid fat.
Others are broken up during working. Finally there is enough free liquid fat present
to enclose all the water droplets, air bubbles and intact fat globules.
9. Factors influencing churnability
Chemical composition of fat
Size of fat globules
Viscosity of cream
Temperature of cream at churning
Fat % of cream
Acidity of cream
Load of churn
Nature of agitation
Speed of churn
11. Mechanism of butter churn
The mechanism of butter churn are following steps :
Cream Preparation: Fresh milk
is allowed to stand, and the
cream rises to the top due to its
lighter density. The cream is
then skimmed off and
collected for churning.
Churning: The collected cream
is poured into the churn body,
and the lid is securely fastened.
The dash or plunger is inserted
through the lid and positioned
in the cream.
12. Agitation: The handle
attached to the dash is
moved up and down or in
a circular motion, causing
the dash to agitate the
cream vigorously. This
agitation causes the fat
globules in the cream to
coalesce and separate
from the liquid, forming
butter.
Butter Separation: As the
churning continues, the fat
globules stick together and
separate from the liquid
buttermilk. The butter
begins to clump together,
while the buttermilk
becomes thinner and
separates from the
butterfat.
Butter Collection: Once
the butter has formed and
separated sufficiently, the
churn is stopped, and the
churn lid is removed. The
butter is then removed
from the churn and can be
further worked and rinsed
to remove excess
buttermilk.
15. Advantages of Butter Churning:
Homemade Quality: Churning butter at home allows you to
have control over the ingredients and quality. You can choose to
use organic, grass-fed cream or milk, ensuring a higher quality
product compared to commercially produced butter.
Freshness: Churning butter at home ensures freshness since you
are directly involved in the process. It allows you to use the
cream or milk immediately after it has been collected, resulting
in a rich and flavorful butter.
16. Customization: Homemade butter can be
customized to suit your preferences. You can
experiment with adding herbs, spices, or other
flavorings to create unique variations of butter
tailored to your taste.
Educational Experience: Churning butter can be a
fun and educational activity, especially for children.
It provides an opportunity to learn about food
production, traditional methods, and the
transformation of ingredients.
17. Disadvantages of Butter Churning:
Time and Effort: Churning butter requires time and
physical effort. It involves consistent agitation or use
of specialized equipment like butter churns. It may not
be practical for individuals with busy schedules or
limited physical abilities.
Yield: The yield of butter from churning can be
relatively low. It requires a significant amount of cream
or milk to produce a small quantity of butter. This can
be a disadvantage if you require a large amount of
butter or are looking for cost-effective options.
18. Equipment and Maintenance: Butter churns or other
equipment required for churning butter may need to be
purchased, stored, and maintained. This adds to the
overall cost and effort involved in the process.
Availability: Commercially produced butter is readily
available in most grocery stores, making homemade butter
less necessary for many people. It may be more
convenient to purchase butter rather than going through
the process of churning it at home.
19. CIP(Clean in place)
Hot water rinsing is the first steps to melt the butter in the churn .
Pump the hot water of 70-80 c through the churning cylinder, washing unit
and through extruder for 20-30 mins.
Caustic soda of 0.5% strength can be circulated after hot water rinse
intermittently to remove the adhered milk soil.
Then wash with hot water to flush out the residues of alkali.
Sanitization using chlorin solution can be achieved by circulating
hypochlorities or chlorides of lime with 200-250 ppm of available chlorin.