I'm in Canada; I use Yogourmet kefir starter. (for the record, I also use Yogourmet's probiotic yogourt starter )

I ferment one liter (= 1 quart) at a time with no fancy equipment. In fact, I ferment my kefir right in the carton

I put an unopened carton of milk into a tall pot of warm (not super hot or boiling) water to bring it up to room temperature or slightly warmer. I pour out a small amount of the warmed milk into a clean cup, then add one packet of kefir starter powder. Mix well until the powder is completely dissolved. Then pour back into the carton of milk and stir - or shake! - well to blend. Loosely close the carton (you want to allow carbon dioxide gas to escape) then put it aside somewhere free from cold drafts for ~ 24 hours. Room temperature is fine (23ºC) .. if your kitchen is coolish, that's okay . it'll just take longer to ferment.

I use ~ 1/4 cup of this kefir to make another batch, following the same steps above. I usually get 3 or 4 subsequent batches before I need to use another pouch of powdered starter.

This has been economically convenient for many years, but I'm seriously looking into acquiring some real kefir "grains". Meanwhile ... the powdered starter works well, and yields a delicious kefir product.

Hint .. try using goat milk for a real taste treat!!!