How Long Does Biltong Take to Dry?

The honest answer to "how long does biltong take to dry?" is: it depends. You'll find everything from "3 days" to "2 weeks" online, and both can be correct. The difference comes down to four variables — and understanding them will give you consistent results every time.

The Four Variables That Actually Matter

1. Meat Thickness

This is the biggest factor. Moisture has to travel from the centre of the meat to the surface before it can evaporate. A 15mm thin stick will dry in half the time of a 30mm thick slab, even in identical conditions. If you want faster drying, cut thinner. If you want that classic thick biltong texture, cut to 25–30mm and be patient.

A rough rule: every additional 10mm of thickness adds roughly 2 days to your drying time.

2. Relative Humidity

This is the variable most people underestimate. Relative humidity (RH) tells you how much moisture the air can still absorb. At 80% RH, the air is nearly saturated — it can barely pull moisture out of your meat. At 40% RH, the air is hungry for moisture and drying is fast.

In Pretoria, winter is ideal for biltong (40–50% RH). Durban in summer is a nightmare (often above 75% RH). If you live in a humid coastal area, you need either a dehumidifier, silica gel in your box, or a very powerful fan to compensate.

3. Airflow

Airflow is the mechanism that removes moisture-laden air from around the meat and replaces it with drier air. A basic 120mm PC fan cuts drying time by around 30% compared to open air hanging. A dedicated biltong box fan does even better because it circulates air within an enclosed space.

Without any fan — open garage hanging — you're entirely dependent on natural air movement. This can work in winter in a dry region, but it significantly extends drying time and increases mould risk.

4. Temperature

Warmer air holds more moisture and moves more actively, which generally speeds drying. The ideal drying temperature for biltong is 22–33°C. Below 15°C, drying stalls significantly and bacterial risk increases. Above 38°C, you risk "case hardening" — where the outside dries too quickly and seals in moisture before the inside is properly dried.

The 4 Phases of Biltong Drying

Based on absolute humidity sensor data from a real instrumented biltong box, biltong dries in four distinct phases:

1. Stabilising (first 6–8 hours): The salt and vinegar are working their way through the meat. Surface is drying but interior hasn't started yet. The humidity delta between inside and outside the box is still low.
2. Active Drying (the longest phase): This is where most of the moisture loss happens. The humidity delta inside the box peaks — you'll actually see your hygrometer reading higher inside the box than outside. This is the sign that drying is working properly.
3. Near Done: The rate of moisture loss slows as there's less water left to remove. The humidity delta starts falling. Check texture every few hours.
4. Done Window: Rate of change approaches zero. This is when you check for doneness — squeeze the thickest piece. Wet biltong gives easily, medium has a bit of resistance, and dry snaps.

Typical Drying Times by Condition

These are estimates based on typical conditions. Your actual results will vary by ±20% depending on your specific setup, fat content of the meat, and how evenly airflow reaches all surfaces.

How to Tell When Biltong is Done

The most reliable method is the squeeze test on the thickest piece:

• Wet biltong: Gives easily when squeezed, no cracking, still noticeably pliable
• Medium biltong: Slight resistance, doesn't spring back, a gentle press leaves a mark
• Dry biltong: Firm throughout, snaps cleanly when bent, no give at all

When in doubt, cut a piece at the thickest point and check the interior. It should be a deep red-brown throughout. Any pink or greyish patches in the centre mean it needs more time.