Cosmic Punch starter

[YeastFeast]

I made a 1L starter with Cosmic Punch yeast and a Propper starter. Put it in a 2L flask and thought that would be plenty of head space with loose foil on top.
Overnight it blew the foil off with dried starter all over the place. Maybe it wasn't as bad as it looked as it still looks like I have close to 1 liter of starter. Probably more foam leaking and drying up everywhere.

My main concern is that the tin foil lid was off all night? Should I be concerned with infection or no big deal in your opinion?
Thanks!

 

[Bobby_M]

Always add a couple drops of fermcap-S into the flask to prevent this from happening. It's not great that the foil was off, but I'd still go for it.

 

[YeastFeast]

Always add a couple drops of fermcap-S into the flask to prevent this from happening. It's not great that the foil was off, but I'd still go for it.

I’ve never used fermcap-S. Will do that next time.

 

[YeastFeast]

Another thought if you don’t have fermcap-S…….would a simple piece or string going underneath the flask and then up over the top of the foil work?
In other words, the string would hold the foil on but let anything on the rise forced out on either side?

 

[IslandLizard]

Another thought if you don’t have fermcap-S…….would a simple piece or string going underneath the flask and then up over the top of the foil work?
In other words, the string would hold the foil on but let anything on the rise forced out on either side?

It may work, but the goal is to keep all your starter inside the flask! You'd easily lose half your yeast with those countertop blow offs. Speaking from experience.

Avoid overfilling the flask/container. Even when using Fermcap, with or without a stir plate.

If you don't want to use a stir plate, use a gallon jug to make 1.5-2 liter starters. And you'd still want to use Fermcap. Gallon jugs (with a screw cap) are also good for making s-n-s ("shaken-not-stirred") starters.

 

[YeastFeast]

Avoid overfilling the flask/container. Even when using Fermcap, with or without a stir plate.

Yeah, I always use my stir plate. I have a 3L flask as well but figured a 1L starter in a 2L flask was plenty of space, guess not! It’s clear now it depends on the yeast.

Is too much head space ever an issue (1L starter in a 3L flask) or doesn’t it make any difference?

Cheers!

 

[IslandLizard]

Yeah, I always use my stir plate. I have a 3L flask as well but figured a 1L starter in a 2L flask was plenty of space, guess not! It’s clear now it depends on the yeast.

Is too much head space ever an issue (1L starter in a 3L flask) or doesn’t it make any difference?

Cheers!

Ah, you are using a stir plate, that wasn't clear from your OP.

Fermcap-S is definitely your friend. Although formulations and instructions may have changed over the years, one drop per starter (up to 2 liters) should be plenty. Store the Fermcap vial in the fridge, but never freeze it. Mine needs to be shaken well, to homogenize, before dispensing.

You can make 1.8 liter starters in a 2 liter flask that way.

Just make sure the stir bar doesn't get kicked or you may have a blow-off again.

Relatively large headspaces are not an issue with starters, within reason of course.

If you have access to oxygen you can jump start your starters with that too.

 

[YeastFeast]

Ah, you are using a stir plate, that wasn't clear from your OP.

Fermcap-S is definitely your friend. Although formulations and instructions may have changed over the years, one drop per starter (up to 2 liters) should be plenty. Store the Fermcap vial in the fridge, but never freeze it. Mine needs to be shaken well, to homogenize, before dispensing.

You can make 1.8 liter starters in a 2 liter flask that way.

Just make sure the stir bar doesn't get kicked or you may have a blow-off again.

Relatively large headspaces are not an issue with starters, within reason of course.

If you have access to oxygen you can jump start your starters with that too.

Great info, thanks!