Can sourdough infect my brewery?

[rossbaker]

This thought only just occurred to me after proving a loaf in my fermentation fridge which also has a nearly finished black IPA. Am I introducing wild yeast into the environment? Or am I being crazy?

 

[Danscraftbeer]

Yep. For sure. (on the tital question) Not a good mix. It may not get into this finished brew (depends on your methods but it can,
and can basically infect the fridge. I've seen photos of people doing (other culture ferments etc in with their brew
but i definitely wouldn't.

 

[Lyrebird_Cycles]

Probably.

The dominant yeast species in many sourdough mothers is a Candida, eg C. milleri or C. humilis. Candida spp are also amongst the most common wild yeast contaminants in breweries.

That being said, I don't know of any instances of the actual species mentioned above being involved in beer contamination, though C. humilis is a common contaminant of barley.

 

[goatchop41]

I am almost positive that I have had this happen. I had a spate of infections in late 2015 through to mid 2016, which caused slight to moderate overcarbonation in the bottle, along with a peculiar flavour and stripping of hop flavours. This also coincided with me having to do some cold side processes (bottling, etc.) at the same bench that I did a lot of my sourdough stuff (mixing, shaping, etc.) because of where I was living. This followed on until I moved and replaced all of my cold side equipment.

These infected beers had a very peculiar flavour to them, almost saison-like. It wasn't until after changing all of my equipment and ridding myself of the issue, that I tried one of them and recognised that flavour - I went straight back to my main fridge, tasted a little sample of my sourdough starter, and bingo! That was almost the exact same flavour.....I now make sure that I don't do anything brewing related in my kitchen that doesn't involve some sort of hot side process.
So be careful!

 

[Mardoo]

Any non-beer yeast or bacterial based fermentation can infect beer during fermentation, if it will consume what's in beer. Sourdough, sauerkraut, vinegar, kimchi, moulds, etc. Always best to keep your brewery separate.

 

[rude]

Yep. For sure. (on the tital question) Not a good mix. It may not get into this finished brew (depends on your methods but it can,
and can basically infect the fridge. I've seen photos of people doing (other culture ferments etc in with their brew
but i definitely wouldn't.

I do Krauts in my ferment fridge
Definately not ideal
I spray with sanitiser which hopefully helps
I also pressure ferment so cant see it getting to the beer

 

[Camo6]

Any non-beer yeast or bacterial based fermentation can infect beer during fermentation, if it will consume what's in beer. Sourdough, sauerkraut, vinegar, kimchi, moulds, etc. Always best to keep your brewery separate.

Also a great excuse to keep women out of your brew cave.

 

[rossbaker]

Thanks for the info guys. Will avoid this in future!

 

[captain crumpet]

Also a great excuse to keep women out of your brew cave.

Yo ease up on the microaggressions, and check your privilege son.

 

[pcqypcqy]

how strict are people when doing yeast starters and things in a ferment fridge? I've got one running at the moment, nothing else in there but the fridge itself hasn't been sanitised or anything and smells a little like fridges do when they've been closed for a while.

The starter is in a 5l erlenmeyer on a stir plate, with a foil cap. Top of flask and inside of foil were sprayed with starsan when I put the cap on.

 

[unwrittenlaw]

I give my ferment fridge a quick spray with bleach and wipe down then a squirt of starsan when I have finished fermenting in it. Doesn't take long.

 

[Danscraftbeer]

how strict are people when doing yeast starters and things in a ferment fridge? I've got one running at the moment, nothing else in there but the fridge itself hasn't been sanitised or anything and smells a little like fridges do when they've been closed for a while.

The starter is in a 5l erlenmeyer on a stir plate, with a foil cap. Top of flask and inside of foil were sprayed with starsan when I put the cap on.

Same with the starter. That's my biggest risk so I have to be careful. I pressure ferment so there is no risk to the fermenter.
I boil water in mine to sanitize the flask and the water that I hydrate the yeast with. Chilled to pitch temp. The foil is dipped in sanitizer then capped with a rubber band. Its not air tight but it will let out co2.
The fridge is sanitized after every brew usually. There's often little spills anyway so a quick spray and wipe over the inside.
This time I had a blow off hose that's sprayed the walls in stout. So its getting the whole spray down with sodium percarb, rince out and sanitize again.....

 

[Lyrebird_Cycles]

Standard lab procedure for things like that is to use a sterilised cotton wool plug to prevent wayward yeast entering the culture.

An ordinary pressure cooker such as the one from Aldi works fine as a small autoclave, just put the cotton wool in a paper bag sitting on a rack to keep it dry and set the pressure cooker to 15mins. Sterilise a pair of tweezers at the same time and use them to manipulate the plug.

Another procedure which is adequate for home use is to simply microwave the cotton wool plug for 60 seconds on full power.

 

[rude]

Cheers LC for the plug of cotton wool idea
Would hate for the plug to fall in the flask though
Do you use heaps so its a nice tight fit ?

 

[Lyrebird_Cycles]

Use enough so that the expansion of the cotton wool holds it against the sides of the flask but not so much that you have to ram it in.

Do a couple of dry runs before committing to something you don't want to lose, you'll get a feel for it pretty quickly.

 

[rude]

Cheers had a think after post
I was a bit quick draw Mc graw
Even over the top with some inside sounds alright
Loose enough for gas to escape
Will experiment thanks once again