Cross-contamination

[Hoppyland]

I've recently branched out into fermenting things that aren't beer.
I reckon that, for the last 25 years or more I haven't had a single batch of beer that was ruined by spoilage organisms of any sort. I put this down to 3 things: Decent hygiene, purging every deadspace from a large CO2 cylinder, and possibly living in a remote area in Scotland - I hardly see fruit flies etc (although I am paranoid when I do!). Luck must also be a player, but after this length of time not a huge one, I feel.
What I'm worried about is: could this all be about to change??
For some reason, I've just become interested in a variety of other fermentation processes. I've made my own bread for some time, to date using baker's yeast, but I've now got 3 sourdough starters on the go. These contain both yeasts and bacteria - and ones that are happy to ferment carbohydrates at room temperature in anoxic conditions - so if they will grow in, and therefore contaminate/spoil beer, my CO2 purging will be entirely futile.
Worse, perhaps, I'm also having a go at more esoteric stuff. At the moment, a type of yoghurt that works at room temperature, and also a thing called "ginger kefir water". This is apparently another yeast/bacterium symbiosis that ferments sugars happily at room temperature in the absence of oxygen.
So, it seems to me, that the probability of some of these "wild" yeasts and bacteria getting into my beer are quite high unless I step up my procedures to virtually genuine sterilisation, which is clearly not practical.
My question, therefore, is this. Has anyone had problems with their beer which they put down to cross-contamination from other fermentation processes?
I'd appreciate the benefit of any experiences, positive or negative. I might also try inoculating a few bottles of beer ( when I produce an indifferent brew!) with a few of these things, just to see if they take hold.

Oops!! Just realised - I thought I was posting this under "General Beer Brewing Discussion.. " and not "General Beer Discussion". Ah, well - shows it's time for bed!

 

[Dutto]

How do you expect a contamination to occur?

Apparently there are zillions of wild yeasts floating about in the air already so adding few more shouldn't make much difference.

When I had kids, I brewed beer and made yoghurt in the same airing cupboard without any problems that I remember and I've also made bread using the yeast from the trub in a brew without making the bread taste horrible.

Surely, your sourdough starters are in sealed plastic containers and liquids are secured in FV's with air-locks? Air-locks and Blow-Off Tubes work in both directions which is why I use a water/bleach mixture in them.

About the only way I can see a significant cross contamination occurring is if you are using the same equipment for making the various yeast derived products; and even then a relatively easy sanitisation regime should be sufficient to prevent it.

Look on the bright side. IF a cross contamination occurs, it will probably be all your own fault and not the fault of some poor innocent fruit fly!

 

[Cwrw666]

Be careful you might end up being responsible for a new craft beer trend - yoghurt beer. Or sourdough beer. Can't be worse than that bottle of vomit beer I had from Tescos a while back, Bakewell Tart or somesuch.

 

[Hoppyland]

How do you expect a contamination to occur?.......

Well, my sourdough starters aren't in sealed containers - they're in Kilner jars with the rubber seal removed, to let CO2 escape. It seems that bread makers (or, indeed, yoghurt or kefir water makers) aren't nearly as concerned about sanitisation as brewers. Apparently, with sourdough starters, provided you keep the culture supplied regularly with fresh flour then the yeast/bacteria mix maintains its own environment (largely through reduced pH). Over time, a particular mix of micro-organisms will develop and stabilise to suit the particular flour you're using, and the environmental conditions. It's reckoned that some cultures have been going uninterrupted for over 100 years.
However, the most likely area where'd I'd expect problems is in the kitchen, where I both bake and brew. Starters and doughs tend to be messy, sticky things, with a propensity to get everywhere! Difficult to get off my hands thoroughly, as well, so loads of opportunity to contaminate the kitchen towel. In the case of the ginger kefir water, it ferments by the activities of a combination of Saccharomyces, Brettanomyces, and 4 different lactic bacteria. I'm assuming that, by making this, I'm deliberately building up numbers of these way beyond levels that would normally be found in my house, hence the worry.
As you say, though, basically its down to me to achieve "biological security" - but I was wondering if anyone had experience of this situation, and whether my concerns were more theoretical than an actual practical problem.
But, anyway, what is this innocent fruit fly of which you speak? There are no innocent fruit flies. I hate 'em all - even though I don't see many! And, yes, my wife does think I'm paranoid when I chase one round the kitchen with a hand sprayer of soapy water......... although she's grown accustomed to a variety of strange behaviours over the years

 

[Hoppyland]

Can't be worse than that bottle of vomit beer I had from Tescos a while back, Bakewell Tart or somesuch.

Well I had to look that one up!!
Oddly enough, Thornbridge Brewery don't go into detail about the vomit bit. Instead, they claim their Bakewell sour beer "is refreshingly tart and dry with a combination of citrusy hops and flavours of grapefruit and bitter lemon." I take it that you wouldn't agree!
I must say that you haven't tempted me to try it - but then I didn't like the Belgian sour beer I did try. Which I guess is why I was worried about large quantities of lactic bacteria getting too near my brews!

 

[Dutto]

If I stick my hands and/or arms into anything to do with brewing I spray them with StarSan solution after washing with Wrights Coal Tar soap and cleaning under my fingernails.

Luckily, I'm not allergic to anything so I haven't got galloping dermatitis or anything similar; but as a retired HSE Manager I guess I should be wearing the kind of gloves that vets use when they explore the nether regions of a cow!

 

[MarkBowie]

Unless you actually contaminate it you will be fine. The yeast in sourdough is in the air and on the wheat hull, that’s why stoneground, organic flour is always recommended (rye flour is always more consistent for the starter). So because of that, if your cleaning/sanitation routine worked before then it’ll work just fine now.

 

[foxbat]

and possibly living in a remote area in Scotland - I hardly see fruit flies etc (although I am paranoid when I do!).

It's your secret ingredient: the fearsome highland midge!

 

[Hoppyland]

Well, I'm ditching the ginger kefir water! Shame really - it didn't taste too great, but then neither did my first beers in the 60s! There could have been something there to work on, but........
I came upon this from an American site. Someone had asked White Labs about their Belgian Sour, and got this in reply:
"The sour mix is a blend of brewers yeast, lactic acid bacteria and brettanomyces. It was designed for homebrewers who cannot fully mimic the traditional spontaneous fermentation method of Belgian Lambic brewing.
Therefore, it can be used for primary fermentation since there is brewers yeast in it. Over time, it will produce the same characteristic sourness associated with this beer style. The sourness will definitely increase over time, particularly if maturing in oak barrels.

The more caution you can exercise while using this, the better. Once the blend takes hold, it can be very difficult to get rid of. It contains very hard, adaptable organisms, so can survive when least expected. It can be cross-contaminated between beers that have not been pitched with it. Keep these beers separate while fermenting.

We recommend using either glass or stainless fermentors, dedicating separate lines to sour beers, and using a rigorous cleaning procedure (wash with hot PBW or other caustic cleaner, followed by acid rinse if possible, and finish with a sanitizing agent). This will ensure you don't infect other beers."

Reading this, the slightly ropey pellicle on the top of my ginger Kefir water has definitely given me the heeby-jeebies. I'm definitely not willing to deliberately encourage very hard, adaptable (and for my beer, spoilage) organisms that can survive when least expected!
If White Labs are saying this about their product, and I'm basically building up huge numbers of the non-yeast element with the kefir water, then it looks like a combination of drain, bin and a load of bleach for me!
I'll still keep on with the sourdough though - the bread is getting better nearly every time
Bad news for me, though, my baking is now more a priority for my wife than my beer - although she does love some of the beers as well, so I've pretty well got carte blanche in the kitchen

 

[Dutto]

I particularly liked the honesty with White Labs comment ...

".... it can be very difficult to get rid of. It contains very hard, adaptable organisms, so can survive when least expected."

In my book, that is a textbook description of a colossal case of infection ...

... so my decision to limit myself to just two yeasts (*) is not looking quite so foolish!

(*)
Wilco's Ale Yeast and Youngs Lager Yeast; plus very occasionally a yeast cultured from a bottle!
(Memo to self: "Do NOT use a Belgian Sour Beer!)

 

[MashBag]

+1 What had already been said...

Plus some experience. I too ferment all sorts. Beer, bread, vino, sugar wine, vinegar, kimchi, kombucha, fermented veg.

I haven't had cross contamination, but that said I do keep vinegar (Acetobactor) very separate.

CO2 purging is irrelevant, as is airborne infection (really).
So my thoughts turn to.....
Are you sharing some tools or hoses?
What was the infection?
What cleaning products are you using?

 

[Chippy_Tea]

WOW, welcome back Dutto

 

[Agentgonzo]

WOW, welcome back Dutto

Old thread. Dutto hasn't been online since last year

 

[Chippy_Tea]

Old thread. Dutto hasn't been online since last year

I was joking, mashbag bumped a thread from 2018 where Dutto posted last (before the bump)

 

[MashBag]

I am confused. How did that appear in "new posts". If I had seen it was that put off date I would never have posted.

 

[Chippy_Tea]

I am confused.

Me too

 

[Agentgonzo]

Me too

Apparently so :

 

[Chippy_Tea]

Apparently so :

It should have read -
I was joking, mashbag bumped a thread from 2018 where Dutto posted last (before the bump) hence my welcome back Dutto comment.

 

[rclarke]

It seems that bread makers (or, indeed, yoghurt or kefir water makers) aren't nearly as concerned about sanitisation as brewers. Apparently, with sourdough starters, provided you keep the culture supplied regularly with fresh flour then the yeast/bacteria mix maintains its own environment (largely through reduced pH).

Actually this is no different from old fashioned breweries who do open fermentation.

When we pitch yeast into wort during brewing, it gives the yeast we choose a competitive advantage over naturally occurring yeast in the environment. The yeast we pitch is carefully selected and cultivated, so it starts with a higher population and specific characteristics ideal for fermentation. The wort provides abundant nutrients, and we control factors like temperature and pH to create an environment where our yeast thrives. By sealing the fermentation vessel, we further protect our yeast from wild yeast. Overall, pitching yeast allows us to have greater control, consistency, and predictable outcomes in the brewing process, resulting in a beer with the desired flavors and qualities.

When you make a sourdough starter, it's similar to pitching yeast in wort for brewing, but with a personal touch. Just like choosing specific yeast strains for brewing, you cultivate a special combination of wild yeast and bacteria for your sourdough starter. This creates a dominant population that gives your sourdough bread its unique flavors.

Creating the perfect environment is important in both processes. In brewing, you control factors like temperature, pH, and nutrients to help the yeast thrive. Similarly, when making a sourdough starter, you provide the right conditions—maintaining an ideal temperature and using a mixture of flour and water—to encourage the growth of your desired microorganisms.

Both brewing and sourdough making involve competition. In brewing, the yeast you pitch outcompetes wild yeast to ensure a successful fermentation. With sourdough, the wild yeast and bacteria in your starter culture beat out any unwanted microorganisms, establishing a dominant population that drives the fermentation process. In both cases, undesirable yeast is always present, it's just not dominant.

The best part is the flavor development. In brewing, the selected yeast strains contribute to the unique flavors and aromas of your beer. Making a sourdough starter allows the wild yeast and bacteria to create those tangy, sour notes that make your sourdough bread yummy.

Some bakers will keep strains of starter for posterity just like brewers, so there's less difference than you might think.