I posted a similar experience to someone on the alcohol content of kefir. I fermented mine for 24 hrs. after taking the grains out.(shaking it thruout the day to keep it mixed and to keep a mold from forming) It makes it stronger,and more tart. When you smell it it should smell like a good yeast. If it smells bad in any way it's bad. The milk should be fresh as can be. I got a weird feeling when I was on a fast for 3 days. Light headed and loopy. Then I learned it can be up to 5% alcohol when fermented. If you are sensative to alcohol you could be sensative to fermented foods all together. I drink the fermented cabbage juice mixed with my kefirin the morn. on an empty stomche I've been doing this for about 3 mo.hoping to add some more of the lacto fermented drinks. I tryed making the rejuvalac it was good I just wasn't read to get serious yet.