Nectarine Blossom Yeast Isolation

Put a few Nectarine blossoms into 50ml starter vial a few weeks ago. Added slurry to another 50ml vial for step 2. Then plated from the vial. Ended up with some bacteria, yeast, and mold. Took 3 individual colonies each to 3 new plates. No mold on any of the 3 new plates. Took a single colony from each plate and put into 3 new 50ml starters. Swiped a double colony from one plate to look at on a slide. Looks like uniform cells at 250x.

Plan is to build up from here, run fermentation tests for attenuation and flavor profile. Then choose the best for a full batch.


Initial plating at day 4

Individual plating of single isolate from plate one.

The three new plates

250x

Initial plating at day 8

New vials of individual isolates

 

No way for me to tell at home. My buddy has a lab at the brewery and I am going to streak the bacteria to see what grows and take it to him for better identification. Hoping it is a wild Lacto.

The bacteria formed mostly in quadrents 1 & 2, while the yeast formed mostly in 2 & 3. I took 1 isolate from 2 and 2 from 3. I stayed away from the bacteria as best I could. I don't see any bacteria colonies on the 3 new plates. Any pathogen harmful to humans shouldn't make it through alcoholic fermentation. Need to get a little closer look in the scope but it doesn't look like I see any bacteria cells in with the yeast cells, but 250x won't get close enough for a definitive result.

 

That's why I said "shouldn't". Always need to be careful when building up wild caught.

Working on DNA sequencing for a future step...

 

Feel free, others may like the info if they decide to venture into isolating.

I shake my vials to let out CO2 as they grow. The original step smelled like vanilla. We will see what comes of it in these future steps.

 

It is really interesting how that happens. My first venture into this type of yeast wrangling was blackberry and peach yeast skin starters that were added to my first real sour beer. After 2.5 years it was judged in a BJCP comp and peach and berry were descriptors. I rebuilt the dregs and fermented a Belgian Blonde ale that had a lot of peachiness to it as well.

 

For sure. I'm getting ready to step the 3 isolates up to 350ml, hopefully tonight, and take a gravity sample before and after to see what kind of attenuation I get. Going slow on these since I have 3 isolates and 2 stir plates. I'll then bump them up to 2L batches for flavor/aroma/mouthfeel/etc.

 

Last night I did a double pressure cooker run on 400ml of 1.020 wort for the next step. Pitched the three vials this morning into their own starters. Will watch the fermentation for a week or so then give it a taste when I step it up to roughly 1500-1800ml fermentation in a lightly hopped wort. That step will get attenuation tested as well as carbonated and tasted for flavor and aroma. The spent starter wort from the vials didn't give off a distinct aroma, mildly funky, nothing off putting.

 

Probably around 15 IBUs and 1.040 OG. Not really trying to inhibit anything. Want to see how the yeast isolates do with a beer as opposed to simply starter wort.

 

The starters have progressed nicely! Good active fermentation, nice krausen, and clear flocculation. Will step up to 1500ml hopped wort for flavor/aroma/attenuation tonight.