What are total solids in milk?
Everything except the water: the fat, protein, lactose and minerals.
All but the waterTotal solids in milk: FAT plus SNF
Everything in milk except the water. Cow milk carries about 12 percent and buffalo milk 15 to 16 percent.
Worked number
Total solids from a slip
Add the two numbers on the slip. FAT and CLR give you SNF first.
Total solids12.44
FAT4.20
SNF8.24
FAT 4.2 and CLR 28 give SNF 8.24, and total solids of 12.44 percent.
Cow and buffalo
Typical and minimum total solids
FSSAI sets fat and SNF separately, so the minimum column here is our sum of the two.
| Milk | Typical | FSSAI minimum fat plus SNF |
|---|---|---|
| Cow | 12 percent (3.5 fat, 8.5 SNF) | 11.5 percent (3.2 + 8.3) |
| Buffalo | 15 to 16 percent (6 to 7 fat, 9 SNF) | 14.0 percent (5.0 + 9.0) |
Sources: Dr Narendra K Nayak, College of Veterinary Science and A.H., Mhow; FSSAI regulation 2.1.2, version of 1 Sep 2023.
On a lot
What 500 litres holds in kilograms
Plants that pay on kg fat and kg SNF are paying for solids. At 1.03 kg a litre, a 500 litre lot weighs 515 kg, and at these readings it holds 64.07 kg of solids.
The plant bill in Doodh Master shows KG FAT and KG SNF for this reason.
Open the calculatorOne lot500 litres
Weight515 kg
KG FAT at 4.221.63 kg
KG SNF at 8.2442.44 kg
Total solids64.07 kg
What is in the can
What milk is made of, part by part
Take the water away and everything left is the solids. FAO's averages show where the difference between cow and buffalo milk lies: nearly all of it is fat.
| Part of the milk | Cow | Buffalo |
|---|---|---|
| Water | 87.8 | 83.2 |
| Fat | 3.3 | 7.5 |
| Protein | 3.3 | 4.0 |
| Lactose | 4.7 | 4.4 |
| Ash (minerals) | 0.7 | 0.8 |
| Total solids (100 less water) | 12.2 | 16.8 |
Source: FAO, Milk and dairy products in human nutrition (2013), table 3.1. FAO's buffalo figure sits above the 15 to 16 percent quoted higher up this page, and the Tetra Pak handbook gives cow milk 10.5 to 14.5 percent, mean 13.0. Sources differ with the herds behind them, so judge by your own average. The parts do not add up exactly to the last line, because FAO drew them from many food tables.
Measure and use
How total solids are measured, and why they matter
Total solids and SNF
The two are easy to mix up. Total solids includes the fat. SNF, solids not fat, leaves it out. So FAT + SNF = total solids, and water + total solids = 100.
In a lab: dry it and weigh it
The reference is the gravimetric method, which simply means measuring by weight. FSSAI's manual sets it out: weigh a little milk in a dish, dry it on a boiling water bath, finish it in an oven at 102°C (give or take 2°C), cool it and weigh again. Repeat until two weighings agree within 1 mg. If 5.000 g of milk leaves 0.622 g, then 0.622 ÷ 5.000 × 100 = 12.44 percent.
At a counter: use the formula
Add FAT to the SNF sum and you get total solids from a lactometer. At FAT 4.2 and CLR 28 the answer depends on the numbers you start from.
- Richmond: CLR ÷ 4 + 1.2 × FAT + 0.14 = 12.18
- Doodh Master default: CLR ÷ 4 + 1.21 × FAT + 0.36 = 12.44
- BIS, IS 10083 as amended: CLR ÷ 4 + 1.25 × FAT + 0.44 = 12.69
That is half a point of spread on one sample, which is why a counter figure and a plant figure rarely match to the second decimal.
Solids in packet milk
FSSAI sets no total solids figure for these either, but its two minimums add up: 15.0 percent for full cream milk, 13.0 for standardized, 11.5 for toned and 10.3 for double toned.
Why solids move
They move with FAT and SNF, so stage of lactation, feed and season all count. The Palampur crossbred cows averaged 13.64 percent in winter, 13.40 in summer and 12.89 in the rains.
What water does
Solids fall in step with added water. Put 10 percent water in that 12.44 percent milk and you have 11.20 percent, under the 11.5 that FSSAI's cow minimums add up to.
Why solids decide the yield
Paneer, khoa and butter are made from solids, so more solids means more product from a litre. FAO reports 14 kg of cow milk or 10 kg of buffalo milk for 1 kg of butter. In the Palampur study, milk at 13.64 percent solids in winter gave 15.50 percent paneer, and milk at 12.89 percent in the rains gave 14.79.
If you sell to a sweet maker, this is the number he cares about, whether he says so or not.
How do I calculate total solids?
Add FAT and SNF. FAT 4.2 and SNF 8.24 give 12.44 percent.
FAT plus SNFHow much total solids does buffalo milk have?
About 15 to 16 percent, against about 12 percent for cow milk.
15 to 16 percentHow much of milk is water?
Whatever is left after the solids: about 88 percent in cow milk at 12 percent solids.
About 84 to 88 percentWhat is the difference between total solids and SNF?
Total solids includes the fat. SNF is everything solid except the fat, so FAT plus SNF equals total solids.
The fatWhy do total solids matter for paneer?
Paneer is made from the solids. In one Palampur study, higher solids in winter gave 15.50 percent paneer against 14.79 in the rains.
More solids, more paneerEnter one supplier.Print one slip.
Open the demoStep 1 of 3
Open the demo
It opens straight away. No sign-up.
Step 2 of 3
Enter one supplier
Code, litres, FAT and CLR.
Step 3 of 3
Print one slip
The demo keeps nothing. Your own account starts with the 7 free days.