Stir Starter/2L flask - what size starter?

I made my stir starter today and got a 2L flask. I realize this is huge and way too big to do my usual 1 pt/ 1/2 cup DME. There is barely enough wort to fill the bottom of the flask. Obviously the vortex goes crazy on the bottom. What am I missing here?

Why such a small starter, do you make tiny OG beers? Have you checked out the pitching rate calculator at mrmalty.com?

I usually go with .75-1L and decant

Bump to 1 liter, then decant, and dont forget Mr Malty...

Tim

I dissolve 228 grams of DME in two liters of water. Once dissolved I put the solution into the flask and boil for 5 minutes, cool and pitch the yeast. This give me a full two liter starter. No reason not to fill the flask all the way. Use some foam control to prevent a volcano and stir at room temperature.

No reason not to fill the flask all the way. Use some foam control to prevent a volcano and stir at room temperature.

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This is why I use 1l and not 2l...
but in the end, it all makes beer, so do what feels good

helpful info: Brew365 Yeast Starter

Tim

MX1 said:

This is why I use 1l and not 2l...
but in the end, it all makes beer, so do what feels good

Tim

Click to expand...

Larger is better. IMO, a one liter starter isn't worth the bother. Foam control is your friend, nothing to fear.

i so scred that up, i make a 2l starter as well, not sure what I was thinking.
<looks around for a beer and puts down his coffee>

There that should help

Tim

MX1 said:

i so scred that up, i make a 2l starter as well, not sure what I was thinking.
<looks around for a beer and puts down his coffee>

There that should help

Tim

Click to expand...

FWIW, the 2 liter mark on most of the 2 liter flasks is considerably below the neck, so there's plenty of head space available in the event that it does get foamy. Even that is sometimes not enough, but I put the stir plate on a rimmed tray so the occasional overflow is very easy to clean up.

I use an old 1 gallon wine bottle...

Tim

MX1 said:

I use an old 1 gallon wine bottle...

Tim

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So do I, but I usually jump up the 2 liter flasks twice then the slurry from those goes into the one gallon jug which is filled to about 3.5 quarts. I only go that big for lagers though. IME, jumping the 2 liter once is adequate for most ales and twice if they are particularly high gravity brews. I never have problems with yeast. Nothing noticeable anyway.

Frodo said:

Why such a small starter, do you make tiny OG beers? Have you checked out the pitching rate calculator at mrmalty.com?

Click to expand...

I have been following the Wiki.


So what is the ratio of DME to water?

I use 100 grams of DME per liter of water.

OK, I'll step it up to that. Also, I used a 12v power supply in my stirplate and the vortex always touches the bottom. It doesn't throw the bar though. Should I use a smaller one or is it OK to have all the bubbles flung throughout the flask?

Holy Cow!!
I have 5v going to a 12v fan and it still tries to throw the bar...
But it's cool, cuz my stir plate is plug and play USB Baby!!!

Tim

no matter what wattage i used (7, 9 or 12v) my vortex is only 2 to 2.5" inches long (does not throw the bar). Is this deep enough? I just finished it last night and havent used it for yeast propagation yet.

You don't really need a vortex. You just want it stirring enough to dimple a little bit and keep the yeasties moving around.

DAmmit! My 12v is too much so I ripped it out and started over. The 6v won't even spin the fan. HUH?????

Kayos said:

I have been following the Wiki.


So what is the ratio of DME to water?

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The target is typically a 10% sugar solution by weight. To arrive at this using DME, dissolve 114 grams into 1 liter of water. The DME is not 100% sugar, so you need to use slightly more of it to get the 10%.

MX1 said:

Holy Cow!!
I have 5v going to a 12v fan and it still tries to throw the bar...
But it's cool, cuz my stir plate is plug and play USB Baby!!!

Tim

Click to expand...

Smaller stir bar or more distance between your magnet and your flask will fix that.

so then, is it bad if it looks like and F5 tornado in the starter?

MX1 said:

so then, is it bad if it looks like and F5 tornado in the starter?

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Not necessarily bad, but there is no benefit to be had with fast stirring. A deep vortex can sometimes interfere with the stir bar to the point of causing it to be thrown or make it rattle. When a deep vortex sucks in a lot of air it can also be quite noisy. A gentle stirring motion is all that is needed IMO. The biggest challenge with DIY stir plates is getting them to spin relatively slowly.

OK, got it fixed. 5v too low, 12v too high. 9v was the key......Houston - we have stirring!