Understanding How to Make Curd Alkaline: The Science and Practical Alternatives

November 21, 2025 •

3 min read

Curd is naturally acidic, with a typical pH ranging from 4.5 to 5.5, a result of the fermentation process. This fundamental scientific fact explains why the question of how to make curd alkaline is a common misconception and cannot be achieved in its final form.

Quick Summary

This guide explains the science behind why curd is an acidic food and provides practical alternatives for reducing its sourness. It clarifies the difference between a food's inherent pH and its metabolic effect, offering methods to achieve a milder, more palatable curd.

Key Points

Inherent Acidity: Curd is naturally acidic, with a typical pH of 4.5–5.5, due to lactic acid produced by bacteria during fermentation.
Alkaline is Impossible: It is not scientifically possible to make curd alkaline after it has formed, as the process of coagulation is caused by acidity.
Adding a Base: Mixing alkaline agents like baking soda into milk will prevent or delay it from curdling at all, as it neutralizes the acid required for fermentation.
Reduce Sourness, Not Alkalize: The best approach is to make a milder, less sour curd by controlling fermentation time, straining the whey, or mixing in balancing ingredients.
Metabolic Effect Nuance: While acidic, some studies suggest curd can have an overall alkaline-forming effect on the body after digestion, but this is different from its actual pH.
Cooler and Shorter Fermentation: To produce milder curd, use a shorter fermentation time and cooler temperature, and move it to the refrigerator as soon as it sets.

Understanding Curd's Inherent Acidity

Curd's characteristic tangy flavor comes from its natural acidity, which is essential to its creation. This acidity is a result of lactic acid bacteria (LAB) fermenting the lactose in milk. Bacteria like Lactobacillus bulgaricus and Streptococcus thermophilus consume lactose and produce lactic acid, which lowers the milk's pH from around 6.5-6.7 to 4.5-5.5. This drop in pH causes milk proteins, particularly casein, to coagulate and form curds. A longer fermentation time or warmer conditions increase lactic acid production and result in a more sour curd. This process is irreversible.

The Science of Lactic Acid Fermentation

The accumulation of lactic acid causes the milk's pH to drop, leading to the coagulation of casein proteins and the formation of curds. The more lactic acid, the lower the pH and the more pronounced the sour taste.

The Myth of Making Curd Alkaline

Attempting to make curd alkaline after fermentation is not scientifically possible and would ruin the product.

Why Baking Soda Prevents Curdling, Not Alkalizes It

Adding an alkaline substance like baking soda to milk before fermentation prevents curdling by neutralizing the lactic acid needed for coagulation. Adding it to finished curd will not make it alkaline but can cause an unpleasant taste and fizzy texture.

How to Reduce Curd's Sourness (Practical Methods)

While making curd alkaline isn't possible, you can make it less sour by controlling fermentation or adding other ingredients.

Method 1: Control Fermentation Time and Temperature

Managing fermentation is key to a milder curd. Less time and cooler temperatures reduce lactic acid production.

Steps for Milder Curd:

Use fresh milk and a good starter.
Ferment in a cooler place than usual.
Check after 4-6 hours; refrigerate immediately once set to stop acid production.

Method 2: Strain the Whey

Straining removes whey, which contains much of the lactic acid, resulting in a thicker, less acidic curd.

Steps for Straining:

Line a strainer with cheesecloth over a bowl.
Pour in the curd.
Refrigerate and drain for several hours for thicker, milder curd.

Method 3: Add Flavor-Balancing Ingredients

Adding ingredients can balance sourness without changing the curd's structure.

Sweeteners: Honey or maple syrup can mask tartness.
Fruits: Bananas or berries add sweetness.
Nut Butter: Adds richness and complements tanginess.

Curd's Metabolic Effect: Acidic vs. Alkaline-Forming

Curd is acidic in pH but may have an alkaline-forming effect on the body after digestion, potentially due to minerals. This is different from its actual acidity and is sometimes why it's used for digestion. The body's pH is primarily regulated by kidneys and lungs.

Comparison: Standard Sour Curd vs. Milder Curd


Feature	Standard Sour Curd	Milder Curd
Fermentation Time	Longer	Shorter
Storage Method	Room temperature for extended periods	Refrigerated immediately after setting
Flavor Profile	Pronounced tangy, acidic, and sour taste	Less tangy, sweeter, and more mellow
Texture	Can be looser	Thicker and creamier, especially if strained
pH Level	Lower (more acidic)	Higher (less acidic)
Lactic Acid Content	Higher	Lower

Conclusion: Embracing Natural Acidity and Reducing Sourness

Curd's acidity is fundamental. Instead of trying to make it alkaline, focus on controlling fermentation to produce a milder curd. Adjusting time and temperature, straining whey, and adding flavors can achieve a desired taste. The concept of curd having an alkaline-forming effect after digestion adds another dimension, highlighting its nutritional benefits and potential digestive aid properties. Curd is a healthy, probiotic-rich food best appreciated by understanding its natural characteristics. [^EverydayHealth]

[^EverydayHealth]: Everyday Health, 'Is Yogurt Alkaline or Acidic?' [Online]. Available: https://www.everydayhealth.com/nutrients-supplements/is-yogurt-alkaline-or-acidic/.

Frequently Asked Questions

No, adding baking soda to milk will prevent it from curdling in the first place because the alkaline properties neutralize the acid required for the process. Adding it to already-made curd will create an unappealing taste and texture.

Curd typically has a pH level between 4.5 and 5.5, which is acidic. The pH of fresh milk starts at around 6.5-6.7 and drops as it ferments.

Yes, as curd ages, the lactic acid content increases, causing the pH to drop further. This is why older curd tastes more sour than fresh curd.

A food's pH measures its actual acidity, while its metabolic effect (PRAL) describes the acid or alkaline residue it leaves in the body after digestion. Although curd is acidic, it is considered an alkaline-forming food in the context of an alkaline diet.

To make curd less sour, reduce the fermentation time, culture it in a cooler environment, and move it to the refrigerator immediately after it sets. You can also strain the whey to remove some of the acidity.

For most people, sour curd is not harmful. However, for individuals with a sensitive stomach or acid reflux, the increased acidity may cause discomfort. The probiotics in fresh curd can often aid digestion.

Straining the whey removes some of the water and lactose, resulting in a denser, creamier curd with a higher concentration of protein and fat per volume. It also makes the curd less sour.