Kefir grains contain quite a few types of beneficial yeasts, INCLUDING CANDIDA! Keep in mind you will never find Candida albicans in kefir. The forms of beneficial candida in kefir are active AGAINST C. albicans.
A yeasty odor from kefir is not abnormal. In fact, a very nice
sourdough starter can be made using equal parts of liquid kefir and whole wheat flour. Adding some kefir whey or spare milk grains to fruit juice will even result in a kefir beer!
Be careful. Dangerous pressure can build when fermenting sweet juices.