Milk
SNF in Milk — Complete Guide to Measurement & Calculation
Everything about Solids Not Fat (SNF) in milk — what it is, how to calculate it, IS 1479 formula, FSSAI standards, and factors affecting SNF.
By Subhendu ·Jan 1, 2025· 2 min read· Updated Jan 2025
What is SNF?
SNF (Solids Not Fat) is the total solid content of milk minus fat. It includes:
- Protein (3.2–3.8%): Casein and whey proteins
- Lactose (4.6–4.9%): Milk sugar
- Minerals (0.7%): Calcium, phosphorus, magnesium, sodium
- Vitamins & Other (~0.1%): Water-soluble vitamins, enzymes
SNF represents the nutritional and technological value of milk beyond its fat content.
SNF Calculation Formula
The standard formula per IS 1479 (Part III):
SNF% = CLR/4 + 0.21 × Fat% + 0.36
Where CLR = Corrected Lactometer Reading (at 27°C)
Temperature Correction for Lactometer
CLR = LR + 0.2 × (Temperature – 27°C)
If milk temperature is above 27°C, add to the reading; if below, subtract.
FSSAI SNF Standards
| Milk Type | Minimum SNF |
|---|---|
| Full Cream Milk | 9.0% |
| Standardized Milk | 8.5% |
| Toned Milk | 8.5% |
| Double Toned Milk | 9.0% |
| Raw Cow Milk | 8.5% |
| Raw Buffalo Milk | 9.0% |
Total Solids vs SNF
Total Solids% = Fat% + SNF%
Example: Milk with 4.5% fat and 8.5% SNF has 13.0% total solids.
Lactometer Reading Interpretation
| CLR Reading | Interpretation |
|---|---|
| > 32 | Possible adulteration (water + starch) or very high SNF buffalo milk |
| 26 – 32 | Normal range for cow milk |
| 28 – 34 | Normal range for buffalo milk |
| < 26 | Suspected water adulteration |
Factors Affecting SNF
- Breed — Buffalo milk has higher SNF than cow milk
- Season — SNF is slightly higher in winter months
- Stage of lactation — SNF peaks early and late in lactation
- Dilution — Water addition reduces both fat and SNF
- Feed — Protein-rich feed improves SNF
- Mastitis — Reduces casein, alters mineral balance
Quick Reference
→ Use our SNF Calculator to calculate SNF from CLR and fat% instantly.