Kombucha for kids
my 19 month old son loves kombucha as well.
I personally don't think that the very little amount that is found in the bottle is going to do much harm. Keep in mind that he isn't drinking the whole bottle, and the whole bottle doesn't have much to begin with. Besides that all the amazing health benefits that you get from kombucha and other fermented foods truly out weight the risk of such small amounts of natural alcohol due to the fermentation. Very little is present.
Also keep in mind that your child is rare in that he has a very healthy diet and lifestyle, so his body will readily be able to detoxify from the little amounts of alcohol that might be present in it.
I personally, think it is fine, and actually wish more parents saw the benefits of kombucha for their children. It is something that I recommend for children as a way to get natural probiotics and amino acids into their diets, especially if they don't have the best of diets and lifestyles.
Keep doing what you are doing, a wonderful job.
Peace and Blessings,