Editor’s Note: Effervescent and salubrious, kombucha is a perfect summer thirst quencher. In “Delicious Probiotic Drinks,” Julia Mueller introduces the art of fermentation with easy-to-follow fun recipes you can brew at home. From kombucha to kefir and ginger beer—there’s a whole world of tasty fermented refreshers to be explored. The following is an excerpt about probiotics and…