[ynotbrusum]

I have a third iteration (3rd year in a row) started on a Blackberry Bretted Saison.  The Saison will receive post-fermentation a few pounds of fresh blackberries and a not yet determined brett strain.  I want to dose the blackberries with some Campden tablets or powdered Potassium Metabisulfite or Sodium Metabisulfate.  I don't know for sure how many pounds of Blackberries I will receive next month (my brother in-law has a patch growing wild behind his property, so I have had 12 pounds in the first year and about 8 pounds last year, the second year).  My question is how does one dose the fruit on a per pound basis.  The first two iterations were not dosed at all, but I want to better control the Brett character and hope to eliminate other wild yeasts or bacteria...  Is it possible that a dosing table exists out there among the sour/mixed fermentation beer/mead/cider community? Also, how long does it take to eliminate the unwanted bugs to become safe to add the Brett strain?  Thanks in advance for any suggestions on this.

[lizaambler]

Following for my pears addition!

[kramerog]

You can rinse the fresh fruit with a 50 ppm metabisulfite solution. IIRC, folks often make a ~75 ppm solution with 1 Campden tablet in 1 gallon - please check the math.  The metabisulfite can interfere with Brett and even bear yeast so the metabisulfite is limited to rinsing.

[ynotbrusum]

Blackberries aren't really able to be rinsed very well - they will be oozing when I get them fresh.  So I will need to add the metabisulfate to a batch of blackberries prior to or after pureeing or macerating  the fruit.

[dmtaylor]

Use 1 Campden tablet per pound.  That's what I've used based on things I read, to good success.  Chill and wait about 48 hours before racking your beer on top of it.  In this dosage, the Campden will kill bacteria and stunt growth of yeast but still allow your own non-bacterial critters to stay dominant.  If you want bacteria you might want to wait at least 4-5 days for the sulfite level to be reduced then re-pitch.  I would do the same for Brett, pitch after the sulfite has calmed down a bit.

[ynotbrusum]

Thanks, Dave.  That sounds consistent with what my fruit wine making friends suggested.  I may go a bit light on that dosage and give it plenty of time (while refrigerated) before racking onto the fruit.  I have a bit of time yet before the berries come in.