How a milk collection centre works, from first can to dispatch

A milk collection centre is a small business with one product and two rush hours. Farmers bring milk morning and evening. Each can gets checked, weighed, tested and priced in front of the man who brought it. Then the milk is pooled and sent on to a dairy, and the money follows on a cycle.

Here is one full day at a private centre buying 500 litres a day from 40 suppliers, with an operator and a helper at the counter. That is 80 cans a day if everyone pours both shifts.

A milk collection centre day at a glance

When	Work	What gets written
Before the shift	Wash up, switch on the machines, check the scale	Date and shift
6 to 9 am	Morning shift: check, weigh, test, parchi, pour	One line per can
After the shift	Cool the milk or send it, wash the cans	Shift total
Middle of the day	Hisaab, uchal, feed sales, calls with the buyer	Supplier ledger
4 to 7 pm	Evening shift, same steps	One line per can
After the shift	Dispatch, close the day, clean again	Day register

The hours come from one trade guide and move with the village and the season. NDDB's description of a society is the same in shape: producers bring milk each morning and evening, a sample is tested, and results go into a test register.

Before the first can

Wash everything that touches milk. Yesterday's film on a measure or strainer sours today's lot.

Switch on the analyser and check the scale reads zero with nothing on it. Put the current rate chart where the supplier can see it, with its date. Check the battery too. NDDB writes village power as 160 to 260 volts with frequent cuts, and its specification includes a UPS for that reason.

The first can, step by step

The man with the can arrives. From here, the order matters.

1. Smell it and look at it

Dairy reception checks are done on each can before it is accepted and weighed. A can with a bad smell should be turned away there. If a can seems doubtful, boil a little: milk with high acidity clots on boiling.

This is the last cheap moment. Once a sour can is in the lot, you own the whole lot's problem. Tell suppliers your rejection rule on the first day, so nobody takes it as a quarrel.

2. Weigh it

The scale reads kilograms, and most charts pay on litres. At 1.03 kg a litre, a 20 kg can is 19.4 litres. Settle on one way and print it on the parchi.

The scale must be verified before you use it in trade, under section 24 of the Legal Metrology Act. NDDB's specification asks for a Class III scale, stamped at site by the local inspector. A scale with no stamp loses you the argument before it starts.

3. Stir, sample, test

Fat rises, so stir first. Take a small sample and number it. An analyser built to NDDB's specification takes 40 seconds a sample, about 70 samples an hour. So 40 suppliers in the morning means about 35 minutes of testing alone, and that is why a queue forms at 7 am.

The test gives FAT and CLR. SNF is worked out from them. A common form is SNF = (CLR ÷ 4) + (0.21 × FAT) + 0.36, so CLR 28 at FAT 4.0 gives 7.0 + 0.84 + 0.36 = 8.2. Charts differ in those constants. The SNF page explains them.

Keep the sample. One trade guide advises a labelled 15 ml sample from each supplier for at least 24 hours. It costs a small bottle and it settles the next morning's argument.

4. Price it

Now the rate chart. Cow and buffalo usually have separate charts, and the morning and evening lines stay apart on every sheet.

Say your chart pays ₹5.50 for each 1.0 FAT. A 20 litre can at 6.0 FAT is 20 × 6.0 × ₹5.50, which is ₹660. Read that can 0.1 FAT wrong and the mistake is ₹11. It sounds small, and on one can it is. On a 500 litre lot the same 0.1 FAT is ₹275. That is why a farmer watches the screen, and why you should want him to.

5. Give the parchi

The parchi carries the supplier's name or code, date, shift, quantity, FAT, rate and amount. Hand it over before he leaves.

The parchi is what both sides check on bill day, and it is the one piece of paper that stops an argument 10 days later. Do not skip it in the rush.

6. Pour it

Strain the milk into the can or the tank. Next can.

Keeping the milk cool

FSSAI's hygiene schedule for licensed dairy establishments asks that raw milk reach the plant within four hours of milking. Milk collected daily should be cooled at once to 4 to 6 °C or lower. A small centre may not hold that licence, but its buyer reads the temperature at the dock all the same.

There are two ways to manage it:

• With a bulk milk cooler. The milk chills at the centre, and a tanker comes once or twice a day.
• With cans. The milk leaves soon after each shift. This suits a centre close to its buyer.

Distance decides this more than size. A centre 20 minutes from the dairy can run on cans for a long time. A centre two hours away will struggle to.

Between the shifts

The counter goes quiet and the hisaab starts. This is when uchal is given, feed is sold, and yesterday's mistakes get fixed. Fix them now, with a note of what changed and why. A correction on bill day looks like cheating even when it is honest.

If a rate changed, the new chart goes up with its date. Entries before that date stay on the old chart. All of this feeds the 10-day bill at the end of the period.

The evening shift

Same steps, same order. Keep the evening's cans, totals and rates apart from the morning's. Morning plus evening is the day's pour, and that total goes into the day register.

Dispatch, and the number that comes back

Before the milk leaves, write down what is going: kilograms, average FAT, temperature and time. Keep one sample of the lot.

Work the average FAT from every can's weight, not from a simple average of the readings. A big can at low FAT counts for more than a small can at high FAT.

Your buyer tests the milk at its own dock and pays on its own reading. You have already priced your suppliers on yours. Whatever falls between the two readings is your profit or your loss. If your 500 litre lot left at 6.0 FAT and the dairy reads 5.9, that gap is the same ₹275, out of your pocket.

Track that gap every day:

• A small gap that stays steady points to your scale or analyser. Get it checked.
• A sudden gap points to one can or one lot. Go back to the samples.

What is on the shelf at the end of the day

NDDB describes a society keeping a set of standard registers, most of them filled daily and countersigned, with test results recorded against each sample number. A private centre has no secretary, but it needs the same habit. By the end of the day you should be able to put your hand on:

• Each can's weight, FAT, CLR, rate and amount, shift by shift
• The day's total for each shift, and the lot sent to the buyer
• Uchal given and feed sold, with dates
• The rate chart in force that day

If you can produce those four, you can answer any supplier and most buyers. If one is missing, you will find out on bill day, when it costs the most to fix.

How the centre earns

There are two common models. On commission, the dairy pays the farmer's price plus an amount per litre. One trade guide gives ₹0.50 to ₹1.50 a litre, which at ₹1 and 500 litres comes to ₹15,000 for a 30-day month. On buy and sell, you set your own chart and live on the gap. Feed sold on credit often adds a margin.

Neither model pays until the buyer does. The centre pays its suppliers on a cycle and is paid on another, and the owner's cash sits between the two.

Where the day goes wrong

Three things break a normal day:

• Power goes in the middle of the shift. Keep the UPS charged and keep a paper sheet at the counter. Copy it in later.
• The queue gets long. Under pressure, the sample gets rushed and the stirring gets skipped. Add a second person at 7 am before you add anything else.
• A reading gets disputed. Bring out the kept sample and test it in front of him.

If you move the counter onto a computer, Doodh Master's milk entry in the Windows app keeps working with no internet and syncs later. It can also read the line an analyser sends over a serial cable. That hardware link has not been bench tested, so ask us first.

Next step: run one morning's cans through the demo and see what the day register looks like at the end.