I have a friend who studies some molecular aspects of probiotic yeasts, some wild ones and also the widespread in medications Saccharomyces boulardii (found in Florastor®, Floratil®, and other commercial names).

He ask me if there is any chance on brewing beer with this, and I've searched on the net, and find some information, but I think its good to know if someone here on this house have tried this before. Available information tells about some banana esters, or 'wheat yeast' profile, but precise info about attenuation, floculation and other consistent feedback is lacking. If no one can help, I will try this in some batch in the future and come back to tell. Thanks in advice.

  • 4
    Please try it and come back to report your results!
    – GHP
    Sep 18, 2014 at 18:00
  • 1
    So did you try? Anything to share on your experience? Cheers !
    – user12564
    Aug 20, 2015 at 0:33
  • This says it produces alcohol, so go for it!
    – Pepi
    Oct 17, 2015 at 3:32

3 Answers 3


I have some experience brewing with s. boulardii. I started by making a mead with it, one gallon at a time. I found fermentation was starting very slowly at first and I was concerned that contaminent microbes were taking dominance. It turns out my city water needs to be boiled for at-least half an hour to eliminate the chloramines enough for brewing. Having done that, the yeast is consistently brewing 12 hours after pitching. I pasteurize the honey by pouring gently into the water as it cools after boiling without mixing. The density and viscosity of the honey prevents it from diffusing to the top and you get to keep the aromatic flavours. I use 750g of honey for a gallon. The result is a ~8% ABV beverage with a flavour similar to cider but without the acidic tartness.

When trying to brew an all-grain blond ale with this yeast, I find it usually coming out tasting like a white beer and also having the same cloudiness. Would probably be a good choice for that style. Since it is my intention consume this as a probiotic beverage, I am happy with the cloudiness, as it assures me the live yeast is present in my glass. It seems it needs a few weeks to age out the aroma. Before that, the hops gives off a bit of a smell that is not what I'd call "floral".


I have ordered some Saccharomyces boulardii and plan to do a test brew this weekend. Going to do 5l/1gallon brew with only pale malt ~1040 OG. Will add a small amount of Perle or saaz depending what is in the freezer.

I will report back in a week or 2, with the recipe and results.

Reporting back... [21 Mar 2016]

Apologies it has been a while, I got it going eventually, and I am not convinced that it fermented to completion, sorry took no readings; I will pop a bottle and take some gravity readings. I have bottled it up and tried some yesterday. It was not hideous, there was a faint sulphur tinge to it, but it tasted OK. I would not say great.

I did not get Banana esters off it, but my kitchen has not been that warm ~ 18C.

It was very cloudy and had not dropped out as I am assuming that s.boulardii has not been selected for this trait. Also, I am not totally convinced it had finished fermenting; it seemed pretty slow.

I'll stick a couple of the bottles in the fridge and see if it drops clear or not.

If I was doing this again what would I change...

  • I used about 10 capsules in the starter, I would up this closer to 40;
  • OR I would collect the flocculated sediment and reuse this, thereby selecting for flocculation;
  • I would probably mix it with some ale yeast, to ensure completion in a faster timeframe;

Await further updates....

[06 Apr 2016]

It is refusing to drop clear, the flavour is not the most appealing in the world. Sightly harsh and astringent.

  • I have a bad feeling my S.Boulardii is dead, I only managed to try this this weekend. The starter did not start. I may have to find some better source, have left it to see if it comes to life over the next couple of days but not hopeful.
    – Mr_road
    Feb 22, 2016 at 9:35
  • 1
    OK turns out this was just a poor starter, left it for 2 more days as got busy at work, and it was bubbling away, added it to a demijohn over the weekend and vigorous fermentation kicked in after 12 hours, was still going strong this morning. Smells OK. Will report back next week. PS: used DME with Perle.
    – Mr_road
    Feb 29, 2016 at 13:21
  • 1
    OK totally forgot about this brew, I just popped open another bottle a further year on. It was bit of a gusher, but once it had calmed down it was astringent, no body from DME, with a slight metallic taste and an almost meaty aftertaste, and most importantly not as unpleasant as last time. Definitely beer, and drinkable, if not the most appealing. It has never drop clear but the sulphur taste has vanished.
    – Mr_road
    Aug 2, 2017 at 22:52

At this point, I have made many one gallon batches of beer, cider and mead using S.Boulardii as my yeast. Cider is by far the easiest. Simply empty a capsule of Florastor or Boulardii Max into a jug of preservative free pure apple juice then stick on your air-lock. If you really want to be cheap and not get a bubbler, you can just put some aluminum foil over the top and crush it onto the threads so it stays covered but not sealed.

The best tasting results from my experience have been in brewing a West Coast style brut IPA. It's all I brew now. Mostly pale malt with a bit of wheat, dry hopped with a variety of aromatic hops imparting flavours of citrus and other fruit. It is normal for beers of this type to be finished and served unfiltered, which goes well with the goal of consuming this as a probiotic beverage.

I believe hefeweizen style would also be a good choice for this yeast. Though, I have not tried this yet. Some have said my IPA reminds them of to Shock Top.

  • Any comments about attenuation or flocculation of this yeast?
    – Philippe
    Dec 16, 2019 at 17:38

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