Day 1 to 7: just mix about 1 tbsp of flaxseed flour with a 100 ml of kefir.

Day 8 to 14: Mix 2 tbsp of flaxseed flour with 100 ml of kefir. Day 15 to 21: add 3 tbsps of flaxseed flour to 150 ml of kefir. Use freshly ground flaxseed if you are unable to get the flour.