Test pH with vinegar and baking soda

Collect soil from 4-5 inches deep. Place 2 tablespoons in a bowl and add 1/2 cup white vinegar — if it fizzes, the soil is alkaline. In a separate bowl, moisten 2 tablespoons of fresh soil with distilled water, then add 1/2 cup baking soda — if it fizzes, the soil is acidic. No reaction to either means the pH is roughly neutral.

Why It Works

Vinegar (acetic acid, pH ~2.5) reacts with alkaline carbonates in soil, producing CO2 gas (fizzing). Baking soda (a base) reacts with hydrogen ions in acidic soil the same way. This gives a quick directional reading of whether your soil is acidic, alkaline, or neutral.

Tips

• This test only detects relatively extreme pH values — it cannot distinguish within the critical 5.5-7.5 range where most garden soils fall
• Vigorous fizzing means strongly acidic or alkaline; slight fizzing means mildly so
• It tells you direction but not a numerical value, and cannot tell you how much lime or sulfur to add
• Good as a quick screening test, but follow up with a lab test or pH meter for precise amendment decisions