Metabisulfite and Wild Yeasts

I've read through a bunch of threads and hadn't seen this mentioned, so I started this new thread. Apologies if it's repetitive.

Last year I had a batch of wild yeast cider turn out unbelievably good at 10 months, much fruiter, sweeter, less boozy than similar recipes with commercial yeasts.

I only have one bottle left, and my first culturing failed, so I hit the web to help find the answer to trying to capitalize on whatever strain dominated that cider and minimize the others. I was stumped on how to get Kmeta to kill the yeast in the raw juice but not kill the wild yeast starter that I would use.

I found a great article that answered most of my questions and really explains the process well. It also explains why my cider was terrible at 3 months and great at 10. If you're at all intrigued about manipulating your cider by playing with yeast, then it's a great read. (The short answer is you use Kmeta to narrow the populations to Saccharomyces, and then they will dominate)

i found it here

For those less interested, it explains why you can just get raw cider and dump a packet of Notti in and be all set.

Journal of Applied Microbiology Volume 84, Issue 5, Article first published online: 5 JAN 2002
"Selective effects of sulfur dioxide and yeast starter culture addition on indigenous yeast populations and sensory characteristics of wine"
T. Henick-Kling, W. Edinger, P. Daniel and P. Monk

When you do a wild yeast ferment, there is a succession of different yeasts. First apiculate yeasts cause the foaming, then saccharomyces type yeasts take over to finish off. If you pitch a wild yeast from last year you don't get the same effect, that's why places that use natural ferments just leave it to nature each year.

I was looking to maintain the local character, but potentially add some control by creating a starter of indigenous Saccharomyces to be added a number of days into the ferment. We own an small orchard, which adds some quirks to the timing before and during the process.

The article is written for local varietal wine production and provides some good data on the resistance, timing and growth rates of colonies for those looking to balance control of indigenous populations and finish with predictable cultured strains.

cheers

I was able to affect the fermentation.

I put 2 campden in a gallon of raw cider and left it at room temperature for 24 hrs and saw no action.

I then pitched it with 2oz of juice from a day 7 wild fermentation. At this point that fermentation should have cleaned up the minor strains activity and was switching from A-type to S.-type strains with relatively good populations of each.

I got a quicker and much more vigorous foaming stage, no brown residue, and much less sediment at this stage.

Whether the resulting product will be better is yet to be seen.

The lesson learned is that you can use sulfite and still use wild yeast effectively.