By the way, this is a terrible idea.

Why?
Well, a kombucha scoby is a SCOBY - a Symbiotic Colony Of Bacteria and Yeast!
So essential oils are inherently antibacterial, most have antiviral properties and a few are also antifungal. Adding essential oils - hopefully not ones that are poisonous to ingest like eucalyptus - kills off bacteria.

Since we drink kombucha to help recolonize the helpful bacteria in our gut, adding essential oils subverts the whole point, and may favour yeast infections.

Want lemon? Add slices of lemon! Want peppermint? Add some mint tea! Want ginger? Add some ginger slices! Want cardamom? Add some crushed cardamom seeds!

If you want kombucha bottles by the way, they are 50% off now! http://www.anarreshealth.ca/product/bottle-glass-swing-top-kombucha-50

I sell essential oils and am a Registered Aromatherapy Health Practitioner and Certified Natural Health Practitioner.