Beyond raw milk: the dairy biorefinery
Most village milk leaves as raw milk. A biorefinery separates it near where it is produced — into ghee, casein, whey and the rest — so that more of what it is worth stays with the people who produced it.
How milk is separated, step by step
Membrane filtration is how the dairy industry sorts milk's parts by size, each membrane finer than the last. This is the order a village plant would use it in.
Microfiltration
The coarsest membrane. Depending on its pores, it takes out bacteria, or separates the casein from the whey proteins.
Ultrafiltration
Holds back the milk proteins and lets water, lactose and minerals through, which is how protein concentrates are made.
Nanofiltration
Lets small salts through and holds back the lactose, which is how some of the salt is taken out of whey.
Drying
Concentrates are dried to powder. Freeze-drying is the gentler and costlier choice, for fractions that heat would spoil.
What milk is made into
Each of these is a part of milk the dairy industry already separates. They are described here as what they are: none is sold by Ojas, and none is offered as a health product.
Ghee, made the bilona way
Clarified butter. In the bilona way, whole milk is boiled and set to curd, the curd is churned with a wooden churn, and the butter that rises is heated slowly until it clears.
- Cooking
- Ritual use, as in the offering poured into the sacred fire
- An ingredient for Āyurvedic makers
Churning parts the butter from the buttermilk. Heating then drives off the water, and the browned milk solids are strained out.
Colostrum
The milk a cow gives in the first days after calving. It is the first feed her calf must have, so only what the calf does not need could ever be collected.
- Cooked into a set pudding — junnu in Telugu, ginna in Kannada, kharvas in Marathi
- Dried, as an ingredient for food makers
Kept apart from ordinary milk. Its fat can be skimmed off and the rest concentrated and dried at a low temperature.
Casein
Most of the protein in milk. It sits in milk as tiny clusters called micelles, and it is what sets into curd and cheese.
- Cheese and paneer making
- Food manufacture
Microfiltration holds the micelles back and lets the whey proteins through; the older way sets it with acid or rennet, as curd.
Whey
The liquid left when milk is set into cheese or paneer. It carries the milk's sugar, its minerals and the whey proteins.
- Food manufacture, including dairy drinks and baking
- Animal feed
Ultrafiltration concentrates the whey proteins; nanofiltration takes out part of the salts.
Milk sugar (lactose)
The sugar in milk. Once the whey proteins have been taken out, most of what is left in the liquid is lactose.
- Food manufacture
- A filler in tablets, in the pharmaceutical trade
Concentrated and crystallised from the liquid that passes through the ultrafilter.