How Much Oxalate Is in sour?
mg oxalate
per serving
Serving: 1 cup (155 g)
Verdict: 🟢 Safe
Per 100g: 0.6 mg
Data: Harvard T.H. Chan SPH (2024)
The bottom line for sour: Safe (🟢), with 1 mg oxalate per serving — comfortably below the 25 mg safe cutoff. There's no need to limit it. Just keep your usual kidney stone basics in place: water throughout the day and calcium-rich foods at meals.
Putting sour in context: it lands well below the category average of 21 mg. In the database, 89% of fruits (101 of 113) fall in the 🟢 Safe group (under 25 mg oxalate/serving). The typical fruits here averages 21 mg oxalate per serving, so sour runs 96% below that baseline. That places it among the lower-oxalate options in its category. Why this matters: the gap between two Safe foods can be wide — one may hold 5 mg oxalate while another sits at 24 mg. The lower one leaves more room in your day. See all fruits rated Safe for a full side-by-side.
Why does oxalate per 100g matter?
Per-100g values put every food on the same scale, which is handy when serving sizes differ a lot between foods — or when your portion doesn't match the standard serving. It lets you compare apples to apples on oxalate density. For sour, the measured oxalate value is 1 mg per 1 cup (Safe).
How accurate is the oxalate measurement?
These values come from Harvard's 2024 ion-chromatography analysis — the gold-standard method for oxalate. Real measured data rather than estimates. Sample-to-sample variation exists, but no published source is more dependable for food oxalate. Applied to sour: 1 mg oxalate per 1 cup — Safe per Harvard (2024).
How does this compare to other foods?
Anything under 25 mg per serving is Safe; 25-99 mg is Caution; 100 mg or more is Avoid. The category pages on OxalateWatch list foods side by side, so you can see where this one ranks. For context, sour measures 1 mg per 1 cup, rated Safe.