How to Skyr Culturing

PRACTICAL WALKTHROUGH · PARAMETERS · COMMON MISTAKES

Thermophilic bacterial fermentation of skim milk producing a dense, acidic yogurt with high protein retention.

Origin: Norse/Viking (9th century) — Iceland

See full technique reference →

What You Need to Know

Lactobacillus delbrueckii subsp. bulgaricus and Streptococcus thermophilus convert lactose into lactic acid at 40-45°C, causing casein micelle aggregation while whey proteins remain soluble. The strained process removes liquid whey, concentrating proteins and creating a thick gel structure.

Produces a yogurt with 10-12% protein content (3-4× regular yogurt) and clean acidic flavor, used as both staple food and cooking ingredient.

Key Parameters

Temperature

43°C

38°C - 46°C

Time

18 hours

12 hours - 24 hours

Equipment

Thermostatic incubatorCheesecloth or microfiltrationSkim milk (<0.5% fat)

Steps

1.
Skyr with birch syrup (Iceland): Base texture carries sweet-tart balance
2.
Skyrkaka (cheesecake) (Sweden): Provides structure without gum additives

The Science

Primary Reaction

C12H22O11 (lactose) + H2O → 4 CH3CHOHCOOH (lactic acid)

Key Variables

Temperature: 40-45°CpH: 4.0-4.5Starter culture ratio: 1:1 L.bulgaricus:S.thermophilusMilk solids: 9-12%Incubation time: 12-24 hours

Common Mistakes

Weak gel formation

Cause: Insufficient acid production (<0.7% lactic acid)

Fix: Extend fermentation time or increase culture dosage

Grainy texture

Cause: Overacidification (>1.2% lactic acid)

Fix: Reduce fermentation time by 1-2 hours

Full technique page Ask The Geist

Foodgeist is developed, created, and maintained by one food geek. It gets lonely. It gets expensive. Say hi →