VitaLac Products

Yoghurt Nature Starter Culture
Definition:

Yoghurt is a fermented milk product, which is produced by fermenting milk with lactic acid bacteria which are responsible for the development of the typical yoghurt flavour.

Historical background: 

Yoghurt 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 yoghurt in Europe in the 7th century. The biologist Metschnikoff attributed the long life expectancy of the Bulgarians to their favourite food: yoghurt. For this very reason yoghurt is also often referred to as “the milk of long life”.

Yoghurt Nature Vital-Ferment contains freeze-dried lactic acid bacteria: Streptococcus (Sc.) thermophilus, Lactobacillus (Lb.) delbrueckii ssp. bulgaricus and glucose.

Sachet Storage: Yoghurt Nature Vital-Ferment can be stored in the refrigerator (4-6°C) at least 12 months.

Ingredients and Equipment Needed:

  • 1 Liter milk (raw, grade-A, whole milk, skimmed milk, milk prepared from milk powder, UHT milk, goat’s or carabao's milk). 

To improve consistency if necessary, add instant skim milk powder. 

  • Yoghurt Maker - In the Philippine setting, you do not need a Yoghurt Maker as the indoor ambient temperature in the Philippines is approx. 24-28C [without airconditioning],  but it takes longer:  10-16 hrs. depending on the temperature. 
  • Thermometer - it would be ideal for a perfect yoghurt.
  • 1 sachet Yoghurt Nature Starter Culture.

 

Preparation, Product yield and Shelf-Life

  • Preparation: Very simple specially if you use UHT-type Milk. Depending on ambient temperature, a batch is finished in 6-16 hrs. Full instructions accompany the product.

Yogurt Production:

Utensils used:

    

 

 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
  1 Dark-colored Cloth or towel  To cover the product from strong daylight while in fermentation
  1 Liter of Milk  We recommend UHT Milk [no need to boil and pasteurize], found in Tetra-Brik packs in any store.
  1 Sachet:  Vitalac Yoghurt Nature - Starter Culture or Ferment
  Thermometer  If not available, you can estimate temperature [see below]
  Yogurt Maker Machine - keeps a constant 40 C temperature and makes yogurt in 6-8 hours [Optional] Important Note: A yogurt maker is optional in the Philippines as our local indoor ambient temperature - between 23-30 degrees C - is ideal for yogurt production without the need of a yogurt maker. The only variation is that fermentation time is somewhat longer: between 6-16 hours.

Process:

    

 

Milk - 1 Liter

Note on Milk used:


1. UHT [type] milk, at ambient temperature, you may proceed directly and add & mix thoroughly 1 Sachet of Yoghurt L+. Using UHT-type milk makes production a lot easier.

2. Other types of animal milk [Pasteurized , raw, etc.]: You will need a milk/food thermometer - Before mixing the Yoghurt Nature ferment, you must pasteurize the milk [even though the milk pack specifies that it is "Pasterurized Milk"] by heating it to 90 degress C [10 degrees below boiling point] for 25 minutes, then let it cool to 40 degress C, and only then proceed to add & mix the sachet of Yoghurt L+.  For yogurt production without the use of a thermometer, see below.

3. If you want more consistency in your yogurt, you may add instant skimmed milk powder [optional].
 

Fermentation Culture -  Add 1 Sachet : 

 VitaLac Yoghurt Nature Starter Culture or Ferment

When the milk is between 23-40 C,  only then can you add & mix thoroughly the sachet of Yoghurt Nature  to the milk and then cover with lid and a dark cloth to shield from strong daylight. 
   

Fermentation Temperature: 


1. Using UHT Milk, as it comes packed from the store, and local [Philippines] indoor ambient temperature [except Mountain Province], which is between 23-30 degress C, is ideal for yogurt production without even the use of a thermometer or a yogurt maker machine.

2.  When using Pasteurized animal or non-animal [soya, rice, coconut] milk - which you must first pasteurize at 90 C for 25 minutes - you must cool the milk to 40 C or below 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. 
 

Fermentation Time: Between 6-16 hours, depending if you are using a yogurt maker or not [indoor ambient temperature]

 Once you have added the Yoghurt Nature sachet, you must leave it be to ferment and avoid frequent moving or agitating.
    Fermentation Time for Yogurt Maker: That specified by your machine or from 6-8 hours
    Fermentation Time without Yogurt Maker: With Philippine indoor ambient temperature, time varies from 6-16 hours, depending on temperature variations.
  Finished Product: Milk solidifies into yogurt 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.
  Re-Innoculation: 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 batch, do a successive batch or re-innoculation of another Liter of milk PLUS 4-6 tablespoons of the previous yoghurt batch to process more yogurt. 

You can make up to 14 succesive 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 L+.

 

  • Product Yield: 14 Liters of milk - The procedure can be repeated up to 14 times.

 
  • Shelf life - Lactic acid produced by lactic acid bacteria has a preserving effect. During this time, however, the acid content will increase since the microorganisms (mesophilic culture) maintain moderate activity even in the refrigerator.

Problem

 Possible causes Our tips
Yoghurt does 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 Yoghurt Starter Culture.

Observe the temperatures and times indicated.
  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 2-3 Tablespoons of  Yoghurt and inoculate the next batch
  Inhibition of the microorganisms. Rinse equipment with clear boiling water before use
Yoghurt becomes grainy The Starter Culture or starter yoghurt [from previous batch] was not evenly distributed in the milk Stir the Starter Culture/ferment or yoghurt into the milk gradually and thoroughly
Taste is too sour Ripening time was too long Observe fermenting time. The longer yoghurt is stored, the more sour it will become since post-acidification follows
Unusual taste / mould or red spots (yeast spores) on the surface The undesired breakdown of the milk components  microorganisms resulting from unclean working procedure Prepare your yoghurt under good sanitary conditions to prevent contamination by foreign microorganisms
  Sources of contamination: insufficiently heated milk, water, air, unclean equipment  Rinse equipment with boiling water, scald the milk, avoid long exposure to air
   

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/starter culture!

 

 VitaLac, 2005