Catching wild yeast with just plain sugar

[gatewood]

I've been catching and growing cultures of yeast for some time now, using mashed/blended fruit and letting it sit outside. However, I've just recently asked myself if I could just forget about the whole fruit pulp business and just boil sugary water (with easy to ferment sugar like glucose or sucrose).

I guess its doable, but will it present any drawbacks?

 

[RPh_Guy]

but will it present any drawbacks?

Yup.

1. Higher pH will allow the growth of unwanted organisms.
2. Without nitrogen the desirable organisms will have more trouble growing.

 

[gatewood]

Yup.

1. Higher pH will allow the growth of unwanted organisms.
2. Without nitrogen the desirable organisms will have more trouble growing.

1. Isn't sugar acidic?
2. Thats an interesting point, so the wort needs to get colonized by nitrifying bacteria as well. I could add a teaspoon of ammonium to fix that problem.

 

[RPh_Guy]

1. Sugar may or may not be acidic enough to bring the pH under ~4.3 (what I recommend) when combined with everything else.
2. "Ammonium" is an ion, so it's not a thing by itself. Did you mean DAP? That's better than nothing but a complex nutrient is the best choice (e.g. Fermaid K or Fermaid O).

 

[gatewood]

NH4

1. Sugar may or may not be acidic enough to bring the pH under ~4.3 (what I recommend) when combined with everything else.
2. "Ammonium" is an ion, so it's not a thing by itself. Did you mean DAP? That's better than nothing but a complex nutrient is the best choice (e.g. Fermaid K or Fermaid O).

1. I see.
2. Well it is NH4+:

https://www.google.com.mx/search?client=opera&q=ammonium&sourceid=opera&ie=UTF-8&oe=UTF-8

The perfect source for nitrifying bacteria to form nitrites and nitrates.

 

[gatewood]

It probably isnt a good idea anyhow. Just wanted to explore the concept.

 

[RPh_Guy]

Well it is NH4+:

https://www.google.com.mx/search?client=opera&q=ammonium&sourceid=opera&ie=UTF-8&oe=UTF-8

The perfect source for nitrifying bacteria to form nitrites and nitrates.

It's basic chemistry. I know what ammonium is.

Ammonium (or any charged molecule) cannot exist by itself in "chemical" form.
You could have something like ammonium chloride (a salt). The negative charge on a chloride ion balances 1:1 with the positive charge on ammonium.

Diammonium phosphate (NH4)2HPO4 is a common salt of ammonium used by brewers (zero net charge).

 

[gatewood]

It's basic chemistry. I know what ammonium is.

Ammonium (or any charged molecule) cannot exist by itself in "chemical" form.
You could have something like ammonium chloride (a salt). The negative charge on a chloride ion balances 1:1 with the positive charge on ammonium.

ooooh... you meant that, didnt know what you meant with DAP .

Diammonium phosphate (NH4)2HPO4 is a common salt of ammonium used by brewers (zero net charge).

Why is that exactly? What about other salts, such as ammonium nitrate?

So, should I consider nitrogen like some sort of fertilizer for fermenters?

 

[RPh_Guy]

Why is that exactly?

Hah, I don't know why. It just is.
Nitrates have generally been considered to be unhealthy, but maybe that is not actually the case. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6147587/

Regardless, I recommend Fermaid O, about 1 g/L in a starter for wild capturing. I would suggest 2g/L if using just sugar water. There is a lot more that organisms need besides nitrogen and sugar.

 

[Miraculix]

Or you could just boil some DME.

 

[RPh_Guy]

With DME (wort) I suggest pre-acidification and added nutrients.

If you're making beer, you should definitely use wort to capture microbes.

 

[Miraculix]

With DME (wort) I suggest pre-acidification and added nutrients.

If you're making beer, you should definitely use wort to capture microbes.

My last successful capture of wild yeast was only a brown sugar wash with some added substances from outside... Mainly berries I found in the bushes.

I first waited till it visibly fermented, then transferred the trub into some hopped dme based wort with about 20 ibus and stepped that starter up a few times till I had an adequate volume which I used to ferment a beer with. I can describe the taste in one word:

HOR-RIB-LE!!!

It was the worst beer I ever made .
I blame the fruit, as they were already overripe and a bit dry, most of them in the bushes were moldy, had to pick the few without any visible mold... I guess it was just bad timing, it was early winter, some sub 0 nights already happened.

It's a bit of a gamble, my wild mead however seemed to be better, at least when bottling. Will age it at least a year before trying again.

 

[gatewood]

Or you could just boil some DME.

ummm... what is DME?

 

[Miraculix]

ummm... what is DME?

Dried malt extract!

 

[JohnMc]

NH4


1. I see.
2. Well it is NH4+:

https://www.google.com.mx/search?client=opera&q=ammonium&sourceid=opera&ie=UTF-8&oe=UTF-8

The perfect source for nitrifying bacteria to form nitrites and nitrates.

Ammonia (NH3) dissolves in water (H2O) to form Ammonium Hydroxide (NH4OH). This solution is really basic (high pH). Add an acid (HSomething) to get the Ammonium salt of (something) and water, which like Rph_guy notes, is neutral. Eg. NH4OH + HCl -> NH4Cl +H2O
Ammonium nitrate is OK to feed microbes, it works fairly well for that. If you put it in something used only for that purpose, you needn't worry about any potential human health issues. Drink a solution of it-that's up to you.

 

[gatewood]

For the record, I managed to get some sediment going in 2 cultures! Though I haven't checked if its actually yeast, they both smell like sweet bread.

I used brown sugar as the growing medium, and it took about 3-4 days to get going.