The reasons behind a thin and watery milk Kefir

Why my milk Kefir doesn't get thick

First of all, it is important to stress that milk Kefir is normally thinner than yogurt and you should never expect it to be as dense and thick as Greek yogurt. The normal density of milk Kefir is similar to a slightly diluted yogurt.

However, sometimes the thickness of milk Kefir doesn’t change even after 12 or more hours of fermentation, remaining almost as thin as fresh milk. What could be the reason for that?

Milk Kefir not thickening can be attributed to several factors. Kefir is a fermented dairy product made from kefir grains, which contain a mixture of bacteria and yeast. The thickness of Kefir is influenced by the fermentation process and many other variables. Here are some common reasons why milk Kefir may not thicken as expected:


Kefir ferments best at room temperature (around 68-78°F or 20-26°C). If the temperature is too low, the fermentation process may slow down, resulting in thinner Kefir.


Kefir needs adequate time to ferment. If you don’t allow it to ferment long enough, it may remain thin. Typically, Kefir is left to ferment for 24-48 hours, but the exact time can vary depending on the temperature and the strength of your kefir grains.

Kefir grains

The health and activity of your kefir grains can affect the thickness of the final product. If your kefir grains are weakened or not enough active, they may not produce the desired thickness. You may need to rejuvenate or replace your kefir grains.

Milk type

The type of milk used can also impact Kefir’s thickness. Whole milk tends to produce thicker Kefir compared to skim or low-fat milk. Using different milk varieties or brands can yield varying results.


Having too many kefir grains in a small amount of milk can lead to thin Kefir. Ensure that you have an appropriate ratio of kefir grains to milk volume. Usually, a tablespoon of kefir grains for every cup of milk is a good starting point.


Proper hygiene is essential when handling kefir grains. Make sure your equipment and containers are clean and free of any residues that might inhibit fermentation.

Inadequate aeration

Kefir needs oxygen to ferment properly. Ensure that you cover your kefir container with a breathable cloth or lid with small holes to allow air circulation. Airtight containers can hinder fermentation.

Inconsistent fermentation conditions

Changes in temperature or other environmental factors during fermentation can affect the final consistency of Kefir. Try to maintain a stable environment for consistent results.

Initial activation

If you’re using new or previously dormant kefir grains, they may need some time to activate and reach their full fermenting potential. Be patient and give them a few batches to get into optimal condition.

If you’ve addressed these factors and your kefir still isn’t thickening, you may want to consult with experienced Kefir makers or consider replacing your kefir grains if they are consistently producing thin Kefir despite optimal conditions.

Alternatively, please have a look at our following advice on how to achieve a thicker milk Kefir:

How to make milk Kefir thicker and less watery?

If your milk Kefir is consistently thin and you want to make it thicker, there are several steps you can take to achieve a thicker consistency:

Use Whole Milk

Whole milk contains more fat than skim or low-fat milk, and this extra fat can contribute to a thicker Kefir. Consider using whole cow’s milk, goat’s milk, or other full-fat milk options.

Adjust Milk-to-Grain Ratio

Increasing the ratio of milk to kefir grains can result in a thicker Kefir. Use a higher amount of milk for a given quantity of kefir grains.

Fermentation Time

Allowing kefir to ferment for a longer period can lead to a thicker consistency. Experiment with longer fermentation times, but be cautious not to over-ferment, as this can result in overly sour Kefir.

Optimal Fermentation Temperature

Ensure that the fermentation takes place at the ideal temperature range, typically around 68-78°F (20-26°C). Cooler temperatures may slow down fermentation, while warmer temperatures may produce thinner Kefir.

Agitate or Stir During Fermentation

Gently stir or agitate the Kefir during fermentation to distribute the kefir grains evenly. This can help in achieving a more consistent thickness, as when stirring, more grains will be in constant contact with fresh milk.

Choose Active and Healthy Grains

Ensure that your kefir grains are active and healthy. If they’ve been sitting unused for a while, consider activating them in fresh milk for a few batches to revitalize their fermentation potential.

Strain and Thicken

After the initial fermentation, strain the Kefir to separate the grains from the liquid. Allow the strained Kefir to sit for a few additional hours at room temperature to thicken further before refrigerating.

Add Thickening Agents

If you’re still struggling to achieve the desired thickness, you can experiment with adding thickeners like powdered milk, gelatin, or pectin to the Kefir before fermentation. Start with small amounts and adjust based on your preferences.

Use Second Fermentation

After straining the kefir grains, you can opt for a second fermentation with fruits, sweeteners, or other flavorings. This can add thickness and flavor to your kefir.

Blend or Mix

If you prefer a creamier texture, you can blend the strained Kefir with fruits or yogurt to achieve a thicker consistency.

Remember that Kefir can vary in thickness naturally due to factors like temperature, fermentation time, and the specific strain of kefir grains you’re using. It may take some experimentation to find the perfect balance for your taste preferences. Additionally, be patient and give these adjustments a few batches to see the desired results, as Kefir can be sensitive to changes in its environment.

This page is for general information purposes only and is not meant as a substitute for professional judgment, neither it is intended to diagnose, treat, cure, or prevent any disease. You should always consult a qualified healthcare professional regarding any health-related condition. This site is a participant in the Amazon Services LLC Associates Program and it may contain affiliate links to