Wild Yeast Harvesting

[boatcapt]

I'm looking to harvest some local yeast over the next few days and wanted to run my process by the collected experts on this forum. I'll break it down step by step.

1. Purchase grapes on the vine from the local produce counter.
2. Wash each grape with starsan to kill off any existing yeast from the place were the grapes originated.
3. Hang my grapes out overnight for a couple of nights (place in a sterilized mason jar during the day).
4. Prepare a small .040 DME starter.
5. Swab the grapes with a sterile cotton swab.
6. Immediately inoculate the starter with the sterile swabs.
7. Air lock the starter.
8. Wait for signs of fermentation.
9. After fermentation is observed, add double the starter and transfer to a stir plate and let it ferment out.
10. Cold crash the starter.
11. Rinse the "yeast".
12. Prepare a couple of DME/agar petri dishes and streak with the "yeast".
13. Prepare three DME starters.
14. Harvest three individual yeast colonies and inoculate each starter with one.
15. Repeat steps 7-11 for starters that seem productive.
16. Brew a 2 gallon test batch using the most viable (productive) yeast from the second starters.

Does my process seem sound? Any REASONABLE suggestions for improvement?

I'm most concerned with step 2. Will the starsan inhibit yeast collection even after it is dried?

Oh and FYI, I live in Puerto Rico so the night temps are about right for yeast harvesting.

 

[boatcapt]

Secondary question that I've wondered about concerning wild yeast harvesting. Since yeast "floats on the wind" (i.e. no form of locomotion), does it really matter what you use to "catch" them? If I'm correct and they have no method of moving toward something they are attracted to (as opposed to something they aren't attracted to), a small bowl of sterile water should receive the same amount of yeast per period of time as a bowl of wort.

Reason I ask is because we have all sorts of crawlies down here that are attracted to anything sweet left out overnight. Not so much to water.

Am I off base on this?

 

[barleywhore69]

I don't think you need grapes to collect yeast. Try the water thing. Or just use wort and strain out the bugs in the morning like they did in this Brewing TV episode: http://www.northernbrewer.com/connect/episode/brewing-tv-episode-42-king’s-coolship/

 

[boatcapt]

I don't think you need grapes to collect yeast. Try the water thing. Or just use wort and strain out the bugs in the morning like they did in this Brewing TV episode: http://www.northernbrewer.com/connect/episode/brewing-tv-episode-42-king’s-coolship/

My thought process on using sterile water vice wort was 1. Since yeast effectively just "fall" into the collection container, using wort served no purpose during the collection phase and 2. To keep my initial bacteria count down. Sure, both will grow when I transfer to my growth medium but hopefully I would have more chance of getting at the yeast colonies before the mold took over.

 

[boatcapt]

Update on the Puerto Rico yeast experiment.

Harvested yeast using the grape profile above but with the following modification:

Instead of putting the whole grape bundle out, I picked five grapes, cleaned them with Starsan, put them in a sterile container which a put outside for 5 nights. During the day I sealed the container and brought inside. The average nighttime temp was 73-80 degrees. After five days I swabbed each grape with a sterile Q-tip which I them dipped in a 50cc starter. After about three days, a small amount of yeast was noted in the bottom of the starter. Stepped this up to a 100cc starter which produced a clean white layer of yeast (approximately 20cc??).

Made a 1L "test" beer today at lunch today consisting of 100g of light DME, small amount of Warrior hops, Irish Moss and some yeast nutrient. Cooled to 80 degrees (had to go back to work!!), pitched the yeast, put it on my stir plate and went back to work.

MAN!! This yeast just took off! BIG foamy white and brown Krausen when I came home. Turned off the stir plate and after about 10 min, my airlock was bubbling along at about 40 beats per minute! Nice beer smell.

My plan moving forward is to let the krausen fall, give the yeast a couple of days to clean up then cold crash, transfer to a couple of bottles, prime and cap. Give them a week or two to condition and then see what it tastes like.

Going to clean the yeast and if the beer tastes good, I'll prepare a couple a plates to try and isolate the yeast from the bad critters that are probably also present. Prepare a couple of separate 1L test beers from individual isolated yeast colonies and the yeast from the best batches will officially be labeled "Puerto Rican Ale Yeast 001."

Anyone want to buy any of this truly exotic Caribbean yeast??? Hahahaha!!

 

[badlee]

Nice work there.
I only ever seem to get slime

 

[BiggieB400]

Bourbon distillers in Kentucky use to do similar things in the fall. I'd suggest a cheese cloth to keep the flies and other large bugs out if you aim for version 2... The bourbon/whiskey crowd typically used a wort as opposed to fruit or water i believe. Good luck!


Sent from my iPad using Home Brew

 

[boatcapt]

I'm cautiously optimistic. Obviously I have obtained a yeast that is very virile and productive given the way it came to life and burned through my starter beer. Question now is what will it taste like? Doesn't seem to be throwing off any bad odors (quite the contrary) but that doesn't mean it will taste good.

I'll be cold crashing it later tomorrow then decant to a second vessel probably this weekend for a week then prime and this bottle next week.

 

[boatcapt]

Soooo...An update. Bottle conditioned two 12 oz'ers from by test 1 L batch and took them to my Local Home Brew Consuming Store for some of my piers to sample. Very favorable reviews. I wanted to brew a very neutral beer so that the yeast would show through. Mission accomplished there. Reviews of the yeast were favorable across the board...no off flavors or residural "taste." When pushed to describe, across the board my local community described it as "crisp" and a little "fruity" (most often flavor noted was grape). No lingering flavor.

After some delay caused by work and vacation and some other family "stuff", I just brewed my first "real" beer with this stuff today. Just a simple Honey Blonde with Magnum/Cascade/Liberty as bittering/flavor/fishing hops...Maris/Honey Malt/Biscuit and Pilsner DME as a partial malt/extract. IG of .052 and a target FG of .012. Did a 1 L yeast starter last night and true to form, the yeast EXPLODED about 2 hours after pitching to the starter! Brewed the batch today and pitched the Liter into the primary about 3 hours ago...AGAIN, CRAZY fast take off! Bubbling along at about 40 beats per minute with a thick brown and tan krausen.

Prior to making the starter I streaked two dishes of .040 wort and Knox gelatin (want to try and isolate individual yeast "colonies")...these too are showing clear growth. Hopefully I'll be able to isolate PR yeast colonies shortly!