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Yogurt:
Types & Processing Methods |
| Yogurt Processing using
animal or vegetable milk ( soya, rice and coconut milks).
VitaLac sells cultures and bacteria for the following
dairy products. |
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I.
Yoghurt
Nature Starter
Culture Sachet* |
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Definition:
Yogurt is a fermented milk
product, which is produced by fermenting milk with lactic acid
bacteria which are responsible for the development of the typical
yogurt flavour. |
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Historical background: Yogurt has
existed for as long as one can remember. Its production began with a
coincidental fermentation of milk. Selective fermentation of milk
began with the discovery of lactic acid bacteria and research
conducted on its features.
The Bulgarians introduced
yogurt in
Europe in the 7th century. The biologist Metschnikoff attributed the
long life expectancy of the Bulgarians to their favorite food: yogurt. For this very reason
yogurt is also often referred to as the
milk of long life.
Yogurt Nature Vital-Ferment contains
freeze-dried lactic acid bacteria: Streptococcus (Sc.) thermophilus,
Lactobacillus (Lb.) delbrueckii ssp. bulgaricus and glucose.
Sachet Storage:
Yogurt Nature Vital-Ferment sachets can be stored in the refrigerator (4-6°C) at least 12
months.
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*Yogurt
Nature Sachets are used only for Animal milks |
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Ingredients: |
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1 Liter milk (raw, grade-A, whole
milk, skimmed milk, milk prepared from milk powder, UHT milk, goats
or carabao's milk). Milk must be at room temperature (not cold
from frig) |
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To improve consistency if necessary, add instant
skim milk powder. |
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Milk
temperature must be between 23-40 C - only then can you add & mix thoroughly the sachet
of Yoghurt Nature |
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1 sachet
Yogurt Nature Starter
Culture. |
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Equipment Needed: |
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1 Plastic container
- The container has to have a with lid and can be of any capacity as long as it can contain >1 Liter of
milk.
Container must be clean of any bacteria as it can kill the Lactbacillus.
Wash thoroughly, then fill with boiling water for 5 minutes to sterilize it and let
dry
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1 Dark-colored Cloth or towel to
cover the product from strong daylight while in fermentation
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Thermometer -
Ideal for a perfect
yogurt. Must be between 23-40 degrees C.
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Optional:
Yogurt Maker - keeps a constant 40 C temperature and makes yogurt in 6-8
hours. In the Philippine
setting, you do not need a Yogurt Maker as the indoor ambient temperature is approx. 24-28C (without
air-conditioning),
but it does take longer to make: 10-16 hrs. depending on the
temperature. |
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| Procedure |
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With
a milk temperature of 23-40 degrees C, add & mix thoroughly
1 sachet
of Yogurt Nature to it, cover with lid and a dark cloth to shield from
strong daylight. |
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UHT
milk is ideal as you can proceed to mix with the
sachet immediately when at room temperature. When using
Pasteurized animal
milk: you must first pasteurize at 90 degrees C for 25 minutes,
let it cool to to 23- 40 C and mix with the
Yogurt sachet (if not, you run the risk of killing all the culture of Lactobacillus, resulting in a liquid, acid milk product but not
yogurt). |
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When
thoroughly mixed, cover with lid and a dark cloth
and leave it to ferment, avoiding
frequent moving or agitating. |
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Once,
your milk solidifies into yogurt, let it ripen in the
refrigerator for 8-12 hours and it's ready for consumption. It
keeps fresh in the refrigerator for 7 days. |
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Product Yield:
14 Liters of milk - The procedure can be repeated up to 14 times. |
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Shelf life - Lactic
acid produced by lactic acid bacteria has a preserving effect. During
this time, however, the acid content will increase since the
micro-organisms (mesophilic culture) maintain moderate activity even in
the refrigerator. |
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II.
Yoghurt L+ Mild
Starter Culture Sachet* |
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Definition:
Yogurt L+ Mild is a fermented milk product, which is produced by
fermenting milk with special lactic acid bacteria.
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Historical
background:
Yogurt L+ Mild is a
modern product made from nutritional, physiologically valuable starter
cultures. Its mildness particularly takes into account present-day
taste trends.
The nutritional,
physiological value of Yogurt L+ Mild is based upon its high
percentage of L(+) lactic acid.
Yogurt L+ contains
freeze-dried lactic acid bacterias: Streptococcus (Sc.) thermophilus,
Lactobacillus (Lb.) acidophilus, Bifidobacteria (Bf.) species and
glucose
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Sachet
Storage: Yoghurt L+ sachets can be stored in
the refrigerator (4°C) at least 12 months. |
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| *Yogurt
L+ Mild can be used for both: Animal & Non-Animal
milks (soy, rice, coconut, etc). |
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| Soy
Yogurt |
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| Procedure |
| Same
as above but with the following |
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Culture
used is: Yogurt L+ Mild Starter Culture |
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UHT
milk (animal) can be used directly from its
container or tetra-pak. |
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Pasteurized
animal or non-animal (soya, rice, coconut) milks
must first be pasteurized at 90 C for 25
minutes then let cool to 23-40 degrees C before
mixing in the Yoghurt L+ sachet - If not, you run
the risk of killing all the culture of
Lactobacillus, resulting in a liquid, acid milk
product but not yogurt. |
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Soy
milk: Other
fermentation times are to be observed: Without
addition of sugar: Inoculation of 1 L milk,
the fermentation time is approx. 10 hours.
With addition of sugar: Inoculation of 1 L milk,
fermentation approx. 5 hours |
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Rice
milk: The final
product will not have the consistency of yogurt -
The resulting product is a fermented drink.
Inoculation of 1 L milk requires a fermentation time
of approx. 10-12 hours. |
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Re-Inoculation
& Production Incidents |
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RE-INOCULATION
- Make more yogurt per sachet |
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Product
Yield: Make succesive batches of yogurt by re-innoculating the culture to
other liters of milk (Repeat Process 14 times) |
Before the third day of each
"finished" batch, do successive batches or
re-innoculation to another 1 Liter of milk PLUS 4-6 tablespoons of the previous
yogurt batch to process more product.
You can make up to 14
successive batches (14 Liters of milk) and even more but from then on, the bacteria progressively looses activity and you may have to adjust your production times
(more fermentation time) or start with a new sachet of VitaLac Yoghurt
Nature or L+ Mild. |
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PRODUCTION
PROBLEMS: |
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| Problem |
Possible causes |
Our
tips |
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Yogurt has not become firm |
Fermentation temperature
& time: The
milk temperature was too hot or too cold when starter
culture was added, or fermentation
time was too short - the ferment was damaged. |
Cool
milk to 40-42°C before adding the Yogurt Starter Culture. Observe the
temperatures and times indicated. |
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The
Yoghurt was stored too long before being used to inoculate the 2nd
batch |
No
later than 3 days after preparing the 1st batch, remove 4 Tablespoons of
Yogurt Mild and inoculate the next batch |
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Inhibition
of the micro-organisms |
Rinse
equipment with clear boiling water before use |
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Yogurt becomes grainy |
The
Starter Culture or starter yogurt [from the previous batch] was not evenly distributed
in the milk |
Stir the
Starter Culture/
ferment or starter yogurt into the milk gradually and thoroughly |
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Unusual taste / mould or red spots (yeast spores) on the surface |
The
undesired breakdown of the milk components due
to the possible presence of foreign microorganisms
resulting from unclean working procedure |
Prepare
Yogurt Mild under sanitary conditions to prevent contamination by
foreign micro-organisms. |
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Sources
of contamination: insufficiently heated milk, water, air, unclean
equipment. |
Rinse
equipment with boiling
water, scald the milk, avoid long exposure to air |
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Dispose
of the entire batch!
Do
not consume the defective batch and do not use it to inoculate a
new batch - Start
a new batch with a new ferment!
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