Sour milk also known as Bulgarian yoghurt covers a wide food range - all products of milk acidification. Acidification gives the milk tart like taste because of either bacterial fermentation or because of acid addition like juice of lemon or vinegar. This acid inhibits harmful bacterial growth and betters the shelf life of the product.
Bacterial fermentation causes production of sour milk; specifically it is termed as cultured or fermented milk. Traditionally making sour milk was simple - allowing fresh milk to be kept warm for some time to allow for fermentation so that it soured. Generally the milk was placed close to a stove. In modern times commercial production of sour milk is different from that which has allowed the milk to naturally become sour.
Sour milk produced by adding acid (microbial organisms may or may not be added) is specifically termed acidified milk. In USA the acids added for producing acidified milk are acetic acid (generally in vinegar) citric acid (generally in juice of lemon) adipic acid, glucono-delta-lactone, fumaric acid, lactic acid, hydrochloric acid, malic acid, tartaric acid, succinic acid and phosphoric acid.
It has been proved that sour milk lowers cholesterol and also there are indications that it prevents cancer. An abundance of bacteria from lactic acid is found in sour milk. This helps to get rid of bacteria that produce toxins located in human intestines. Research has shown that by removing these bacteria that are toxic, longevity is increased. What are these bacteria of lactic acid?
The bacteria in lactic acid cause coagulation of milk and forming of curd during the process of fermentation. The bacteria of lactic acid feed upon lactose that is in milk - thus this name. As the feeding goes on the milk gets broken down and lactic acid is released inside the milk. With the production of more of this acid the milk turns thick and becomes sour milk. Sometimes the process is controlled so as to produce other products like cottage cheese and sour cream. The fermentation can happen also at home if the milk is allowed to be left in the room at normal temperature or beyond the expiry date. Then the fermentation will take place automatically, rapidly and naturally.
Generally people think that coagulated milk to be spoiled as it has "gone bad". But if storing of the milk is done in a controlled proper manner (30 - 40 degrees C) then a product will emerge that is not only useable but also healthy. This controlled method of fermentation produces yogurt - an item that is commercially available.
Sour milk is not spoiled milk. All that has happened is change of flavour that gives the milk greater tart like taste. Few ingredients are required - most probably the stuff is already in the kitchen like lemon juice and or vinegar apart from the milk.
The whole milk or 2% of it may be used. Skimmed milk should be avoided because it does not tango well with traditional recipes for making sour milk. Pour a cup of milk from a measuring cup.
Add to it vinegar (1 teaspoon) or juice of lemon. Stir well.
The mixture should be allowed to set (10 - 15 minutes). The milk will now curdle; solid particles will become visible in this milk. This means the milk has become sour and is ready for using in other recipes. If curdling does not happen within the framed time then addition of more juice of lemon or vinegar will be necessary.
Generally it can be said that all kinds of sour milk are easily digestible. For the human system this assimilation is beneficial. Moreover the appetite gets improved, the pancreas and liver functions are stimulated and the same can be said about bile secretion.
There are even more additional benefits. Partial curdling of proteins in the milk because of acidic interference causes easier digestibility - the composition's amino acids gets well absorbed by the human bloodstream. This has been termed preliminary external digestion - a feature that refrains from diminishing biological significance of the proteins as the content of amino acid remains unchanged.
The most important health benefit got from sour milk is that it lowers cholesterol. If the "bad" cholesterol is high then it invites multiple diseases - focusing on heart problems. Cholesterol build-ups are largely responsible for heart attacks and other related conditions. Research indicates that consuming sour milk products helps to bring down body cholesterol and this in its turn reduces the chances of heart problems.
Anti-cancer properties are present in both commercial as well as home-made products of sour milk; this has been indicated. Sour milk contains probiotics and these inhibit the growth of carcinogens in the human body. Also the bacteria produce greater intestinal acidity; this helps in removing fecal mutagens that can be the cause of some kinds of cancer if they are allowed to remain unchecked.
Also, sour milk is an excellent calcium source for those who are prone to lactose intolerance. Those plagued with lactose intolerance are not able to easily digest lactose; this results in digestion related problems like diarrhea and gas. Lactose intolerance could be inherited or it may suddenly surface as one grows older. Data shows that 70% of humans suffer from lactose allergy. In sour milk lactose is broken down already and thus those suffering from lactose intolerance have no difficulty in consuming it.
The most wonderful plus point about sour milk is that it gives a boost to the human immune system. Many research studies have shown that probiotic bacteria present in sour milk causes the immune system to get stimulated so that it gradually becomes stronger. Thus it is a natural healthy way of giving a boost to the human immune system for people of all ages - young and old. All benefit from a strong immunity shield.
If yogurt or sour cream is rubbed on, the skin will become smoother, lighter and firmer. Some people with fair skin contend that rubbing of whey on the skin helps in tanning if one gets exposed to the sun immediately afterwards.
For super smooth skin it is advised to add to the bathtub one cup of sour milk. Some essential oils too could be required if odour is too strong.
Another plus point is sour milk's remarkable power of eliminating toxins. Some research has shown that sour milk is able to stimulate the pancreases, and give a kick to liver functions. It helps to get rid of numerous toxins that spell poison for the human body. Also it has been noted that the immune system gets boosted from sour milk. The reason is that milk that has been fermented contains a range of nutrients and vitamins plus other rich compounds that the immunity system requires. Furthermore sour milk helps to check cholesterol levels and reduce allergic outbreaks. Thus one should not wait to take the best benefits from sour milk for improving health and well being.