How to mass-produce water kefir and extend its life?

Hi,

I would like to mass-produce water and flavored kefir for sale locally
My questions are:
1. Can I bottle them in a plastic bottle?
2. How long is the shelf life ot water/flavored kefir? Do they have to be kept refrigerated at all times?
3. How to extend their shelf lfe?
4. Can I ship them?

Thank yo so much Tweet