Hi Razzle,
No one in the Kefir making group that I belong to seems to know if an allergy to brewers or bakers yeast will be made worse by the use of real kefir. I, like others, like to call what we have as 'real kefir' as it is a non-commercial kefir.
There are a couple of kefir sites that I lurk on;
www.kefir.net/users.sa.chariot.net.au/~dna/kefirpage.htmlIf you are still interested in making your own kefir, I have some 'starters'. You can send me an email if you wish & we can discuss it.
Wish I could have been more helpful!!
Trav