"Bilona" comes from the wooden churner, the bilona or madhani, that Indian households have used for centuries to turn curd into butter. The word is on a lot of labels now. The process behind it has not changed much, and each step exists for a reason. Here is how it goes, start to finish.
Step 1: Boiling the milk
Fresh whole milk is brought to a boil and then allowed to simmer briefly. Boiling does two jobs. It makes the milk safe to ferment, and it changes the milk proteins in a way that gives a thicker, more even curd. Traditional dairies usually do this on the day of milking.
Step 2: Cooling and setting the curd
The milk is cooled until it is lukewarm, roughly the temperature at which you could hold a finger in it comfortably. A small amount of curd from the previous batch is stirred in as a starter. The milk is covered and left to set, usually overnight.
This is the step that most commercial ghee skips entirely, and it is where bilona ghee gets its character. The bacteria in the starter convert some of the milk sugar into lactic acid and produce aroma compounds, diacetyl being the best known, which later survive into the ghee.
Setting time depends heavily on the weather. In a Rajasthan summer the curd may be ready in five or six hours. In a North Indian winter it can take twice as long, and dairies wrap the vessels or keep them near a warm stove.
Step 3: Churning
The set curd is churned whole. Traditionally that means a wooden churner with a rope wound around its shaft, pulled back and forth by hand, or turned by a bullock in larger village setups. Many dairies now use slow motorised churners that copy the same back-and-forth motion.
A little cool water is added during churning. After a while, small flecks of butter start to rise to the surface and gather into soft lumps. What remains below is chaas, or buttermilk.
Churning curd recovers less fat than a cream separator does. That inefficiency is the main reason bilona ghee costs more: a large share of the fat in the milk simply stays behind in the buttermilk.
Step 4: Collecting the makkhan
The white butter, makkhan, is lifted out by hand and gently pressed or rinsed in cold water to remove buttermilk trapped inside. Leftover buttermilk in the butter burns during the next step and can give the ghee a sour or scorched edge, so this is not a step to rush.
Step 5: Heating the butter
The makkhan goes into a wide, heavy vessel over a low flame. First it melts and foams. The water in it, which can be 15 percent or more of the butter's weight, slowly boils away. The foam subsides and the liquid turns clear.
Then comes the part that decides the flavour. The milk solids settle to the bottom and begin to brown. The aroma changes from buttery to nutty. The person at the stove is watching colour and listening: the loud crackle of boiling water fades to near silence when the moisture is gone.
Stop too early and the ghee retains moisture, which shortens its shelf life. Go too far and the solids burn, giving a bitter, acrid smell. A good maker takes it to a deep gold and stops.
Some cooks drop in a few curry leaves, a betel leaf or a pinch of salt at the end. These are regional habits rather than part of the core method, and most packaged bilona ghee is left plain.
Step 6: Straining and cooling
The ghee is left to settle for a few minutes, then strained through fine muslin or a steel mesh to catch the browned solids. Those solids, called kharchan or ghee residue, are delicious and do not go to waste in most homes.
How the ghee is cooled affects its texture. Slow cooling tends to produce large, grainy crystals, the danedar texture people prize. Rapid cooling gives a smoother set. We have written more about why ghee turns grainy if you want the detail.
Step 7: Packing
The ghee is packed once it has cooled enough to handle but is still pourable. Glass and food-grade steel are the most common choices for traditional ghee because neither passes flavours into the fat.
How long it takes
From milking to a finished jar, the process usually spans at least a day and often two, most of that spent waiting for curd to set. The churning and cooking themselves take a few hours. Compare that with a cream plant, which can go from raw milk to packed ghee within a single shift, and the difference in cost stops being mysterious.
Why anyone still does it this way
Mainly for flavour. The fermentation step and the slow cooking give bilona ghee an aroma that cream ghee does not have. Whether that is worth paying for is a personal decision. We think it is, which is why both our A2 Gir Cow Ghee and our Desi Cow A2 Ghee are made this way.