What is a scoby?

It basically means a wonderful collection of different probiotics and yeast that work together symbiotically.

KEFIR

The Water and Milk Kefir Grains are a SCOBY that reside in a polysaccharide and protein matrix together. They replicate in the water or milk and digest the food into beneficial chemicals. 

KOMBUCHA

The Kombucha SCOBY is often mistaken. When you make Kombucha, you get a pellicle form, usually at the top of the fermentation liquid. This is a by-product of the fermentation and is a gelatinous disc of cellulose. The actual SCOBY is the bacteria and yeasts that live within the fluid. . 

The Pellicle can protect the fluid from contamination from the the surface, it does contain a large number of the probiotics, but is not essential for brewing. A new pellicle will form after each brew. 

So where can you get them? 

There are a number of groups on social media where individuals offer these Grains and SCOBYs for free. It's a beautiful community of fermenting lovers. I regularly use "Fermenting Friends UK" on Facebook. 

Facebook marketplace is also  great place to start. 

A store bought, non-pasteurized, PLAIN kombucha can also be used as a starter SCOBY. 

Otherwise, there are many online stores offering these starters.  ETSY or Amazon are great!