volcano science fair project - aka first yeast starter

[tt0027]

Made my first yeast starter using wlp400 last night and woke up to find fermentation had blown off my foil top on the flask. I'm not sure how long it was uncovered for over night. Is it still OK to use? Or is there any way to tell?

Details:
Wlp400
1liter starter in flask (650ml volume after boil)
Using stir plate
Used 100g extra light pilsner dme

 

[pabloj13]

Wow. Are those numbers right? That starter was almost 1.060! That's way too high IMO.

 

[tt0027]

Agreed, the og came out really high ~1. 056. But I thought maybe my reading was off. Followed the Mr malty plan of 10 to 1 (100g to 1 liter total volume) then boiled for 15 min. Did I misread something with that?

 

[pabloj13]

Yeah that's correct, but that is for final volume. Have to account for boil off.

 

[tt0027]

Damn. Guess I'm out the $6 on this one... plus the money I spent on the 1l flask as that will be way too small for a 1l starter if I'm to end up with a 1l final volume.
Thanks for the quick reply. If I might ask, what do you use to account for boil off and determine OG based on batch size?

 

[pabloj13]

Damn. Guess I'm out the $6 on this one... plus the money I spent on the 1l flask as that will be way too small for a 1l starter if I'm to end up with a 1l final volume.
Thanks for the quick reply. If I might ask, what do you use to account for boil off and determine OG based on batch size?

Yeah I use a 2L flask and start with ~1.6L before boiling (for a roughly 1.5L starter). I just simmer gently for 10-15 minutes. I also shoot for closer to 1.030, since that way if I over boil a little I'm still good.