Wild Yeast Capture - Fail

[CJV8]

I've been trying to capture some wild yeast from the garden, but after 8 jars I've had zero success. Does anyone with successful experience of this have any ideas as to my lack of success?

The garden is full of fruit trees currently in blossom.
I made a 1040 worth with light DME, with a drop of low alpha hops and pH corrected with lactic acid to 4.5.
Left out over night, about 15 hours, with the minimum temperature around 5°C with a single layer of cheesecloth over the top.
Everything sanitised.

A few developed fuzzy mould on the surface, but the rest have done nothing at all, despite being kept at approximately 20°C for a week.

There's nothing obvious I can see that I've done wrong, but the lack of anything suggests I'm not doing anything right either.

 

[Sadfield]

I've done this, and the only thing I see different is I didn't lower the pH. I suspect this is too hostile an environment for yeast growth. If anything being able to monitor pH and observe a drop is one of the tools of confirming successful yeast capture and growth. I followed the advice here.

https://bootlegbiology.com/diy/capturing-yeast/
Another useful article from the author of American Sour Beers: Innovative Techniques for Mixed Fermentations

https://www.themadfermentationist.com/2011/04/ambient-spontaneous-yeast-starters
There may also be some useful information in this thread.

https://www.thehomebrewforum.co.uk/threads/the-mixed-fermentation-thread.80526/
My experience is documented here in an old homebrew website blog, if you scroll down to part 4.

 

[MashBag]

Strawberry leaves or grapes

 

[foxy]

I've been trying to capture some wild yeast from the garden, but after 8 jars I've had zero success. Does anyone with successful experience of this have any ideas as to my lack of success?

The garden is full of fruit trees currently in blossom.
I made a 1040 worth with light DME, with a drop of low alpha hops and pH corrected with lactic acid to 4.5.
Left out over night, about 15 hours, with the minimum temperature around 5°C with a single layer of cheesecloth over the top.
Everything sanitised.

A few developed fuzzy mould on the surface, but the rest have done nothing at all, despite being kept at approximately 20°C for a week.

There's nothing obvious I can see that I've done wrong, but the lack of anything suggests I'm not doing anything right either.

Try the kitchen, I have got good results, once was within 12 hours.

 

[CJV8]

Cheers everyone, I'll give all these another go.

Sadfield thanks for the tip on not dropping the pH. I dropped the pH as it's meant to inhibit bacterial growth, as suggested by Antidoot in Craft Beer Brewing. But as a couple went fuzzy anyway it's clearly not foolproof!

 

[Sadfield]

The hops should do a reasonable job of inhibiting lactobacillus. The optimal temperature for Lactobacillus and Pediococcus growth is around 30-40°C, so keeping the sample at low room temperature, and using yeast nutrient if you have it, should favour the yeast. Mould can't grow without oxygen. If you grow the yeast in a small vessel with an airlock, the yeast should inhibit mould growth as it produces CO2.

I'd avoid capturing yeast within the home, as its most likely to be saccharomyces from baking or brewing, or those that love human bodies. Plus there will significantly more bacteria you won't want to grow. Humans are filthy.

Good luck

 

[YeastFace]

I would love to do this. But my house is sandwiched between a farm who are mid muck-spreading and a water (read ****) treatment plant I'm not so sure it's a good idea

The in-laws have a lovely plum tree so I think I'll try to grow something from that once they start fruiting.

 

[foxy]

A good series about yeast on these videos.

 

[chthon]

Isn't autumn also not the best time of the year to do this?

 

[Sadfield]

Either spring or autumn, when air temperature is under 15°C. Obviously avoiding too low and freezing your sample. Similar to the seasonality of lambic brewing.

 

[CJV8]

Due to be dry and breezy tonight, down to about 6°C, so 4 jars of wort out, fingers crossed.
No pH adjustment, yeast nutrient (Fermaid O) added and the cheesecloth cleaned with only boiling water and not Starsan (just in case the acidity of the Starsan was being a barrier to the yeast).
Placed among strawberries, raspberries, rhubarb and under a couple of acers (trees, not laptops...).

 

[foxy]

Due to be dry and breezy tonight, down to about 6°C, so 4 jars of wort out, fingers crossed.
No pH adjustment, yeast nutrient (Fermaid O) added and the cheesecloth cleaned with only boiling water and not Starsan (just in case the acidity of the Starsan was being a barrier to the yeast).
Placed among strawberries, raspberries, rhubarb and under a couple of acers (trees, not laptops...).

This week I am making 2.5 litres of sour to go into my Irish Foreign Extra Stout, but I will be getting my wild yeast out of a packet, makes it a lot easier.
Also looked up the 'Wasp' angle on yeast which came up quickly in the second video, interesting read the wasp carries hundreds of different species in its gut, this is where yeast hibernate, they also turn up in the gut of the wasp grubs.

 

[CJV8]

Another week, another fail... BUT, I'd also say there's a degree of success this time. 2 of the jars had signs of fermentation (I put a sandwich bag over the top held on with an elastic band), but both had mould starting or established. 2 smelled pleasant and fruity, one smelled of stinky feet.

One snippet I read the other day was about limiting available oxygen, so I've filled the latest jars about 3/4 full, previously they were only half full. This is the last attempt as it's getting warmer overnight.

 

[Sadfield]

Another week, another fail... BUT, I'd also say there's a degree of success this time. 2 of the jars had signs of fermentation (I put a sandwich bag over the top held on with an elastic band), but both had mould starting or established. 2 smelled pleasant and fruity, one smelled of stinky feet.

One snippet I read the other day was about limiting available oxygen, so I've filled the latest jars about 3/4 full, previously they were only half full. This is the last attempt as it's getting warmer overnight.

Why is that a fail? It sounds like you've got something in two of them

From the link above.

Monitor For Signs of Fermentation: Day One + Two Weeks


There’s A Fungus Among Us

1. Within a few days there should be the tell-tale signs of fermentation, with a small amount of CO2 bubbles coming to the surface of your jar or minor air lock activity. Don’t worry if you don’t see signs of activity quickly. Compared to a normal starter that has had billions of yeast cells accustomed to barley sugar, a comparatively small amount of wild microbes have started colonizing your wild yeast starters.
2. ABSOLUTELY DO NOT TASTE until fully fermented out. Never taste any starter unless active fermentation has been verified for a sustained period of days.
3. Roughly two weeks (assuming each jar or growler has fermented out) it should be safe to taste. Make sure you scrape off any mold, unless that’s your thing (please just do it). The presence of mold doesn’t mean your wild yeast starter is ruined, it’s just a common part of the process. If you have a pH meter, compare the current pH to the reading you took before putting the jars outside. If the pH dropped significantly you’re probably safe. If the pH increased for any of your jars, discard the liquid and move on.
4. Use the smell test first. If it smells good (honey, citrus, etc), you’ve probably got something fun. Creamed corn is a common aroma from certain wild yeast, and these strains often do not flocculate well. If it smells good, use a sanitized pipette to pull a sample from underneath the surface. If it tastes remotely palatable, and has dropped clear…you likely have something INCREDIBLY AWESOME.
5. You’re now ready to create agar plates so you can isolate your own yeast. You know you want to.

 

[CJV8]

I've kept one of them, the one that looked least infected (just a couple of small floaters), but the others were visibly furry with sizeable rafts of mould growing.