While it is stated in the recipe to let the kvass sit at "room temperature for two days before transferring to the refrigerator," I gave it an extra day. As well, the instructions say that "when most of the liquid has been drunk, you may fill the container with water and keep at room temperature for another two days" for a 2nd batch.
I decided to pour off most of the liquid into new jars and refill them instead of waiting to drink it all. While it hasn't been refrigerated, I wanted to taste the 'brew.' Well, it tastes a little better than the store bought stuff, but I am still not crazy about it. (Song reference, Crazy by Seal). I am hoping that a little refrigeration will aid the taste. If not, I might try to tweak the recipe and try again. If after a second attempt it still doesn't suit me, I will just stick to the kefir.