• Please visit and share your knowledge at our sister communities:
  • If you have not, please join our official Homebrewing Facebook Group!

    Homebrewing Facebook Group

Yeast uncovered for a month in fridge

Homebrew Talk

Help Support Homebrew Talk:

This site may earn a commission from merchant affiliate links, including eBay, Amazon, and others.

Micky_cruz17

Member
Joined
Nov 17, 2016
Messages
10
Reaction score
2
About 4 weeks ago I did a starter which I wasn't able to use and it's been sitting in my kegerator for all that time covered with aluminum foil poked with holes. Do you guys think it's still good to brew with it? It was done using WLP002
 
Why would you poke holes in the foil? Without the holes I'd say decant and make another starter with the slurry. With the holes it's basically open to whatever is floating around in the fridge. I'd toss it if it had been like that for a few hours even.
 
It has holes from when I had it in the magnetic stirrer so that it could get more oxygen for the yeast reproduction stage. I just forgot to change the foil when I put it in the fridge.
 
To be fair, during fermentation, theoretically CO2 should be pushing up and out and nothing will drop in. But when that’s over, you gotta seal air tight.
Um . . . what?

The whole point of the foil is to prevent things falling into it. The holes then defeat the purpose of the foil.
 
Leaving the foil loosely draped over the flask while on the stir plate will allow sufficient Oxygen ingress and keep nasties from falling into the starter. Absolutely no need to poke holes. ccous is correct to a point, but before the starter begins active fermentation there is nothing to keep the nasties out.

Hopefully this thread has helped you and you won't make the same mistake again. We all have made mistakes and most have learned from them.
 
To be fair, during fermentation, theoretically CO2 should be pushing up and out and nothing will drop in. But when that’s over, you gotta seal air tight.

That is not how it works. Things would fall/go in even if there is CO2 going out.
 
To be fair, during fermentation, theoretically CO2 should be pushing up and out and nothing will drop in. But when that’s over, you gotta seal air tight.

Yeah, that's not true.

Fermentation won't be creating enough CO2 fast enough to create expanding gas that would literally push bacteria, yeast, dust, and other items away from the entrance of the starter. You would need a fan in order to move enough air to accomplish that. If you've ever put your hand over a starter (or even a 5 gallon batch of beer that's fermenting) you'll notice it isn't generating enough CO2 for you to feel it on your hand, let alone push anything out.
 
I use a air lock, or blow off tube on every starter.

Air lock and blow off tube works but both prevents oxygen from entering the flask.

The reason for using foil is that it prevents stuff from falling into the flask but sill allow for exchange of gases (CO2 out, Oxygen in)
 
Air lock and blow off tube works but both prevents oxygen from entering the flask.

The reason for using foil is that it prevents stuff from falling into the flask but sill allow for exchange of gases (CO2 out, Oxygen in)
I use to do this, after having a 1.5L starter bubble over I had to switch the methods.
 
I use sanitized Aluminum foil for my starter. No holes. This allows O2 to get in and nothing floating in the air to get in.

With the scenario you describe, I would dump it. It has a good chance of being contaminated.
 
I have a 2L, I don't think anything bigger will fit on the stir plate I have.

A 2L has a 16 cm diameter base, a 3L has an 18 cm diameter base, while a 4L has a 20.6 cm diameter base. Your stirplate will hold a 16 cm diameter flask, but not an 18 cm diameter flask?

Does your stirplate have sides?
 
Yeah, that's not true.

Fermentation won't be creating enough CO2 fast enough to create expanding gas that would literally push bacteria, yeast, dust, and other items away from the entrance of the starter. You would need a fan in order to move enough air to accomplish that. If you've ever put your hand over a starter (or even a 5 gallon batch of beer that's fermenting) you'll notice it isn't generating enough CO2 for you to feel it on your hand, let alone push anything out.
Sorry for the poor application of physics; I was just trying to cut the guy a little slack since he was getting destroyed. Maybe you could get away with it on the plate only, but for sure enough O2 will get in on the sides. Yes the holes are uncessesary and most likely harmful even in the short term on the plate. Most definitely not good for storage in the fridge.
 
Back
Top