Milk Kefir Second Fermentation

What is second fermentation?

First fermentation is the usual 24-hour fermentation process: add kefir grains to fresh milk, leave it at room temperature for 24 hours, then strain out the grains to obtain milk kefir.

Second fermentation means allowing the finished milk kefir to continue fermenting without the grains. After this second fermentation, the kefir becomes thicker, contains more probiotics and less lactose, and has more noticeable bubbles and a stronger alcoholic flavor.

Once the first fermentation is complete, you have three options:

1. Drink it as it is.
2. Add fruit, vegetables or other ingredients to make a smoothie.
3. Add ingredients you enjoy and carry out a second fermentation.

What can you add for a second fermentation?

The choice of ingredients is entirely up to you. Here are some of our favorite flavor combinations:

Fruit: Apples, mangoes, strawberries, berries, blueberries and peaches all work well.

Spices: Sprinkle nutmeg, cinnamon or cocoa powder on top, or stir it into the kefir.

Something sweet: A little honey or maple syrup.

Herbs: Lavender and thyme work well.

How do you do a second fermentation, and how long does it take?

Put the finished milk kefir in a bottle and leave it at room temperature for about 1–6 hours, or refrigerate it for 7–48 hours. As fermentation continues, more lactic acid develops, the flavor becomes more sour, and the probiotic content increases. When trying a second fermentation for the first time, open the bottle and taste it every few hours, using a clean spoon. Stop fermenting when the flavor suits you.