Starter question...48 hours

[gregkeller]

So a quick question. I am brewing tomorrow afternoon, janets brown, and i made my starter yesterday, about 48 hours ahead of anticipated pitch time. I couldn't make it earlier because my only 2L flask was on the stirplate with another starter for a batch i brewed yesterday. So I have two options as I see it, and I'm not sure which on is best.

1. Leave starter on the stir plate until pitch time tomorrow and pitch the entire 2 liter starter into my fermenter. I don't think I want to do this because, well, who knows what that 2 liters of beer will do to my 5 gallon recipe. I do want to do this because i figure it will get me maximum yeast cells.

2. Leave on the stir plate until tonight (~10pm or so), then throw into the fridge for ~15 hours to let most of the yeast floc out, then decant most of the beer off the top and pitch a concentrated slurry. I want to do this because it will put the least amount crumby beer into my batch, and I don't want to do this because I'm worried that a. i will be preventing myself from getting the full amount of yeast out of the starter. If this wasn't a big beer, I wouldn't be as worried, but planned OG is 1.068. b. I'm also worried that most of the yeast won't floc out after 15 hours, and i'll pour off lots of yeast. I'm using wlp001.

right now my gut says to throw it in the fridge tonight, let what can floc out and pitch that. I am thinking that even if the yeast is stressed a little i won't get tons of weird esters from it reproducing much, being that it's a neutral yeast. I guess i could also let the wort sit for an extra 12-15 hours and pitch the yeast the next morning, but I worry about contamination getting a hold.

Any and all ideas are greatly appreciated.

 

[Golddiggie]

IME, 24 hours on a stirplate is normally more than enough time for a starter to finish. I'd put it into the fridge when it's done and let it cold crash until you're into the boil. Then decant (carefully of course) but leave about 1/4" of spent starter on top of the yeast. Let it warm to closer to the chilled wort temp and then make it into a slurry and pitch. If you have a strong enough magnet, remove the stirbar either before you put it into the fridge, or use it to hold it in the flask when you pitch. I use a very strong rare earth magnet to do that.

 

[gregkeller]

So I ended up throwing it in the fridge, and i've got a nice thick layer of yeast in the bottom of the flask. Who knows if it's enough for this beer, but i'm thinking it will be. I came home from a party last night, and there was all kinds of kreusen all over the outside of the flask, so my thinking was there was tons of yeast sex going on by that point and I had the 274 billion cells for fermentation i needed.

 

[Golddiggie]

What size flask and what size starter??

I add a drop, or three, of fermcap when I'm boiling the starter (or just before it hits boil) so I don't make a mess on the stove, or counter later. I've had my starter volumes to the full line (2L in a 2L flask, for example) and not had any issues. If you're using a top cropping yeast, then you lose a good number of yeast cells over the side of the flask.

I'll be trying a two step starter this week, for next weekend's brewing. I'll be making a 1L then 1.25L starter with cold crashes between. This will get me to my target yeast cell volume far better than trying to make a much larger starter. Otherwise, I'd need a 5.25L starter. While I do have a 5L flask, it won't fit into my fridge. It will be easier to use my 2L flask with the cold crash between. Plus, I'll use far less DME this way.