Testing Sulfite Levels in Apple Cider

Learn how to test sulfite levels in apple cider using simple test strips. Understand natural sulfites, low-sulfite cider, pH-dependent dosing, and how to manage free SO₃ ion concentration for stable, great-tasting cider.

Sulfites play an essential role in cider making, balancing microbial stability, flavor preservation, and shelf life. While small amounts occur naturally during fermentation, most makers add sulfites in the form of potassium or sodium metabisulfite to prevent oxidation, maintain freshness, and ensure consistent results. Testing sulfite levels helps cider makers-from beginners to experienced hobbyists—control quality throughout the fermentation and bottling stages.

The effectiveness of SO₃ ion depends strongly on pH. Lower pH means less sulfite is required for microbial protection. The typical targets for home cider makers are:

• pH 3.0-3.3: add ~50 ppm sulphite
• pH 3.3-3.5: add ~100 ppm sulphite
• pH 3.5-3.8: add ~150 ppm sulphite

Monitor your cider with confidence using Indigo® sulfite test strips & pH 3–6 test strips, and calibrated droppers. Whether you want traditional sulfite protection or low-sulfite, minimally processed cider, accurate testing helps you control flavor, stability, and shelf life from pressing to bottling.