Is Corn Starch Acidic or Alkaline?
Corn starch (raw) is slightly acid-forming: Positive PRAL: acid-forming after digestion.
Classification
Corn starch is just barely acid-forming at +1.0. Pure starch contains only traces of protein and phosphorus and almost no potassium, so a small surplus remains. A tablespoon for thickening a sauce weighs about 10 g and adds about +0.1. Corn flour, with the protein of the whole endosperm, is many times higher.
In the Grains, Bread & Pasta category, corn starch (raw) ranks #9 of 121, sorted from alkaline to acid-forming. More alkaline options include Sweet corn (+0.7), Buckwheat bread (+0.2), Potato starch (−0.4). More acid-forming are Rye flour (+1.1), Schupfnudeln (potato noodles) (+1.3), Garlic bread (+1.4).
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 corn starch
A dry serving (50 g) of corn starch adds +0.5 to your daily balance. These three bring it back; the grams shown offset exactly this serving.
Frequently Asked Questions
Is corn starch 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: Corn starch (raw) has a PRAL of +1.0 per 100 g, so it counts as slightly acid-forming in your daily acid-base balance.
Do I have to avoid corn starch on an alkaline diet?
No. What counts is the balance of the whole day, not a single food. Corn starch is slightly acid-forming; with enough vegetables, potatoes and fruit on the same plate, the meal stays balanced.
Corn Starch 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 Grains, Bread & Pasta: Grains, Bread & Pasta 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.