Brettanomyces Starter Spoiled?

[simonjn]

Hi there,

So I was making a Brettanomyces starter to use for a 100% Brettanomyces fermentation. Unfortunately, a gnat got into the starter. Is the starter completely ruined and will it spoil the beer? Do I need to create a new starter? Or if I pitch this will the beer turn out okay? Thanks.

 

[Dgallo]

So nothing inherently bad for you will be able to grow in the beer with the ABV and drop in ph, that said the wild bacteria and yeast that are on the flys are now in your starter and will be part of your culture now. Some of these may not have a great flavor profile and can potentially ruin the beer.

Can you brew with it?
Yes.

Should you brew with it?
Your call.

Would I brew with it?
No

 

[simonjn]

Thanks for the info @Dgallo. So I’m generally concerned about acetobacter taking root, although perhaps with the low amount of oxygen in the carboy it won’t? More importantly, can the acetobacter permanently contaminate my plastic tubing and plastic bottling bucket, even after sanitation?

 

[Dgallo]

Thanks for the info @Dgallo. So I’m generally concerned about acetobacter taking root, although perhaps with the low amount of oxygen in the carboy it won’t? More importantly, can the acetobacter permanently contaminate my plastic tubing and plastic bottling bucket, even after sanitation?

I mean acetic acid producing bacteria or AAB is definitely going to be on the flies. It’s also in the air all around you, on flowers and fruit— It’s one of the most common bacteria’s groups in the world. the cell count and how much o2 is in the headspace will determine how much acetic acid is produced.

Will it contaminate you equipment? Not necessarily but it has the potential to do so.

 

[IslandLizard]

One "gnat" (fruit fly, perhaps?) may not add enough AAB to ruin your starter, especially when it contains enough alcohol already.
Reasoning is, most homemade starters* (not in a sterile laboratory environment) are likely tainted somewhat but seem to work fine.

You could let the starter finish and try some of it in a small batch of wort and see what happens.

 

[simonjn]

My friend wanted to pitch it so we did. He’s more optimistic that there won’t be any contamination.

How can I avoid AAB from contaminating my equipment? Clean the hell out of it with star San?

 

[Snuffy]

One "gnat" (fruit fly, perhaps?) may not add enough AAB to ruin your starter, especially when it contains enough alcohol already.
Reasoning is, most homemade starters* (not in a sterile laboratory environment) are likely tainted somewhat but seem to work fine.

You could let the starter finish and try some of it in a small batch of wort and see what happens.

Ok. So a gnat throws something odd into a brett starter. How the heck could you ever even tell? "Hmmm.. this horse blanket barnyard thing is being thrown off by... what... wait... is that gnat?"

 

[Dgallo]

Ok. So a gnat throws something odd into a brett starter. How the heck could you ever even tell? "Hmmm.. this horse blanket barnyard thing is being thrown off by... what... wait... is that gnat?"

I mean you’ll definitely notice acetic acid lol

 

[Hoppy2bmerry]

My friend wanted to pitch it so we did. He’s more optimistic that there won’t be any contamination.

How can I avoid AAB from contaminating my equipment? Clean the hell out of it with star San?

I would clean with a hot soak of PBW, rinse well then sanitize with iodophor. That with stain any patches or film that didn’t get clean so you can have peace of mind, then sanitize a second time with starsan. That will work for tubing as well, which isn’t very expensive to replace if it can’t be cleaned. Sanitizing with 2 different solutions can eliminate a broader spectrum of organisms.

 

[lumpher]

How many people have got fruitflies, gnats, etc in their beer when using water in airlocks and it's been perfectly fine? I'm thinking close to 100%. I'd go for it.

 

[day_trippr]

I've never seen a bug in anything I've brewed, ever.
Mostly luck, I assume, but there's "living right" to consider, too

Cheers! (And brewing indoors )

 

[suprchunk]

While gnats/fruitflies may wander into an airlock...the purpose of the airlock kicks in and keeps it out of the beer. So 100% a working airlock wouldn't allow bugs in. So the analogy is not correct; that just because we've had them in airlocks has zero bearing on infections, unless they somehow swim up and out.

 

[simonjn]

Update: So we transferred it to secondary over the weekend, and it tasted great. It was definitely funky, and you could taste acetic acid, but it was a good level that added sourness. I did try to make sure I had less headspace in the carboy so there’d be less oxygen to produce acetic acid. We’ll be conditioning it on dried sour cherries and Pinot noir shortly