Choosing between HTST and LTLT is the first major fork in any dairy plant's engineering decisions. Both reach the same pasteurization endpoint — they take a very different path.
HTST in one paragraph
72°C, 15 seconds, continuous flow through a plate or tubular heat exchanger. Throughput from 1,000 LPH to 20,000+ LPH. Very thermally efficient (regenerative heat recovery up to 92%). Best for: fresh drinking milk, fluid dairy at scale.
LTLT in one paragraph
63°C, 30 minutes, in a jacketed batch vessel with slow agitation. Throughput per batch from 100 L to 5,000 L. Lower equipment cost. Gentler on heat-sensitive components. Best for: cheese starters, yogurt pre-treatment, specialty products, small operations.
The decision in 4 questions
- Daily volume: under 2,000 L/day → LTLT often makes more sense.
- Product mix: making cheese or yogurt? LTLT preserves enzyme activity better.
- Energy cost: regenerative HTST recovers 80–92% of heat — at scale, this beats LTLT economics.
- Operator skill: LTLT is more forgiving for crews still learning thermal processing.