Kefir and Ketosis


Before going keto I used to take a glass of kefir every morning. I culture my own Kefir. Is it ok to continue or does Kefir throw you out of Ketosis, it being a milk product?

Greek Yogurt
(Danielle) #2

You could always do your own n=1.

Are you able to measure your blood ketones?

I wouldn’t be the best person to advise you when to test to see if it kicks you out of ketosis.

Maybe @richard could help you with that

(Kim) #3

Being fermented, there should be no sugar left in the milk/kefir as that is what has happens in the process the bacteria eats the sugar

(Carol E. ) #4

I believe all of the lactose is not consumed by the bacteria. Using information below, I conservatively subtract 1/3 of the carbs listed on plain, commercial kefir or from the original milk product if homemade.

“One cup of plain kefir made from nonfat cow’s milk has 110 calories. The 240 g serving contains only 2 g of fat, 12 g of carbohydrate, and 11 g of protein. There is some residual sugar from the milk, about 8 g, which is about 3 percent of the 240 g serving. With 3 g of fiber, the net carbs are only 9 g.”

(Carol E. ) #5

For homemade kefir, a secondary fermentation may be done to further reduce lactose.


A second fermentation can be performed for the additional bacterial content, reduced lactose content, or simply for the improvement in flavor.

“Fermenting the kefir a second time, no matter the additions, mellows the kefir and takes away some of the sharp acidic flavor milk kefir is known for. Not only that, but with the addition of other flavorings, it can be a spicey, sweet, or savory fermented drink.”

The link includes text (in addition to the video highlighted in the link).

Shoutout to my original kefir teacher!


I haven’t been making my own kefir lately, but when I was I always went through the secondary fermentation process - not because the taste mattered, but for the additional reduction in lactose.

I also drank the kefir in combination with sources of fat such as MCT oil and eggs to minimize the effect of any remaining carbs.

(Carol E. ) #7

I had a friend who like is so sour it could curl your toes! I’m pretty sure she never refrigerated her homemade kefir.

(Larry Lustig) #8

Would this not also have the full whey content of the original milk? @richard’s just-released n=1 trial indicates that might be more insulin-producing than an equivalent amount of carbohydrates.

(Chelsey) #9

You could also experiment with the fermentation process, like using kefir grain vs. the powder, and experimenting with how long you let it ferment. I ferment my kefir on the countertop for 3-4 days in the winter and my house is set at 68 degrees. I would think that the longer it ferments, the less lactose is left in it.
But I’ve been wonder the same thing about kefir. I have a wonder holistic MD and she encourages me to drink 16oz. raw homemade kefir daily and is also on board with the keto diet, that I just started about 2 weeks ago. So I’ll have to do the n of 1 to see how that will work for me.

(Larry Lustig) #10

Kefir is about 6% sugar.


Thank so much for providing this link. I’m looking forward to trying some flavored Kefir.

(Genevieve Biggs) #12

Thank you!!! I was making kefir for a while, but stopped drinking due to the sour taste. I definitely want to try with second ferments now. Thank you!!!


Thanks everyone for your help.

(Smita Patel) #14

Same here!! I have been working on gut healing with kefir and about to go keto so I am very interested in this conversation.

(Cheryl Meyers) #15

Thanks for the link – I have just realized I have been leaving the grains in my kefir all the time! Will try straining it… the flavoured versions look delicious. :heart_eyes:

edit: Actually, now that I’ve read more, I realize that the powdered starter I use isn’t going to produce big grains. Mine is more like a loose yogurt. Straining just made greek yogurt consistency.


Interesting info! My kefir grains have been in the freezer for years. Probably dead by now.

(Carol E. ) #17

Worth trying to revive?

(Chrissy Quick) #18

I’m on Keto. I make my own kefir but I occasionally buy store bought full fat. I drink 1/2 cup three times a week. My ketones have always been fine. I’ve also added 1/2 cup berries and still fine.

(Circe_D) #19

100 ml of Kefir has, 2g de carbos netos, 4 g de proteinas y 4 g de grasas… aporta 60 kcal.

(Circe_D) #20

To myfitnesspal Homemade - Whole Milk Kefir, 24 Hr Fermentation
Serving Size : 1 Cup/ Kcal 104 / 1g de CH/ 8g Grasa/ 8g de proteina