Is Soy Sauce Acidic or Alkaline?
Soy sauce (prepared) is slightly acid-forming: Positive PRAL: acid-forming after digestion.
Classification
Soy sauce comes in at +1.2 per 100 ml, making it slightly acid-forming. The fermented soy protein and the wheat bring phosphorus that the potassium doesn't quite offset. Since you rarely use more than a tablespoon, its contribution is tiny. The high salt content is a separate matter: sodium isn't part of the PRAL formula.
In the Herbs, Spices & Sauces category, soy sauce (prepared) ranks #60 of 75, sorted from alkaline to acid-forming. More alkaline options include Fenugreek seeds (+0.8), Remoulade (+0.6), Gravy (+0.5). More acid-forming are Pesto, green (+1.3), Mayonnaise (+1.5), Sweet mustard (+1.8).
Acidic or alkaline: PRAL, not pH
On this site, acidic and alkaline refer to the PRAL (potential renal acid load). It estimates what a food leaves behind once it has been digested: a positive value is acid-forming, a negative value is alkalizing. That is different from the pH of the food itself: a lemon tastes sour, yet its PRAL is −4.0, so it is alkalizing. Your diet does not change your blood pH. It does change how much acid your kidneys have to deal with.
What balances soy sauce
A teaspoon (5 g) of soy sauce adds +0.1 to your daily balance. These three bring it back; the grams shown offset exactly this serving.
Frequently Asked Questions
Is soy sauce acidic?
It depends on what you mean by acidic. The pH describes the food itself, for example how sour it tastes. The PRAL describes what it leaves behind after digestion: Soy sauce (prepared) has a PRAL of +1.2 per 100 ml, so it counts as slightly acid-forming in your daily acid-base balance.
Do I have to avoid soy sauce on an alkaline diet?
No. What counts is the balance of the whole day, not a single food. Soy sauce is slightly acid-forming; with enough vegetables, potatoes and fruit on the same plate, the meal stays balanced.
Soy Sauce logged, balance checked.
Basentracker adds up every meal automatically and shows whether your day is in the alkaline range. The same values as on this page, all 977 foods, photo scan, recipes.
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Compare all Herbs, Spices & Sauces: Herbs, Spices & Sauces table. Common questions are answered in Acidic or Alkaline?, and the PRAL calculator adds up a whole meal.
Source: Basentracker food database (PRAL according to Remer & Manz, calculated from protein, phosphorus, potassium, magnesium and calcium per 100 g). This information does not replace medical advice.