2 liter yeast starter?

I'm brewing a vanilla coffee imperial stout in 2 days and just broke my smack pack for starter. I'm expecting an o.g of around 1.08. Will a 1 liter starter be sufficient? What ratio dme to water should I use (preferably in cups). Thanks

 

You will want to keep a lower OG in your starter to not stress the yeast out so I tend to aim for a starter gravity between 1.040-1.045. And for the starter you will want to do a 2L if possible as 1L wont have a sufficient cell count. If you are not equiped to do a bigger starter I would recommend doing about 1/4 pound of DME per liter. Do a 1L starter, let it ferment out and stick into the fridge to let the yeast drop off. Then decant the liquid off the top of the yeast and add another Liter of wort and let it ferment out again. Then you should have enough yeast.

I would play around with this site: http://www.brewersfriend.com/yeast-pitch-rate-and-starter-calculator/

 

Ok thanks that's great. If I'm correct I'm reading that I need 200 grams for 2 liters. I have the capability for that size starter. I've never done any higher than 1 liter before. When I'm ready to pitch should I have it in fridge and pour out most of top then swish yeast cake around and pitch? Or will it make no difference to swish the whole thing around and just pitch it all?

 

It depends how fresh your yeast is, but you are probably looking at a starter between 1.5 and 2 liters.

 

I always pull it out of the fridge and decant, at least 4 hours before pitching and add 500mL of fresh starter wort and put it back on my stir plate until I pitch.

I've had krausen is as little as 1 hour doing this.

Also doing a 1L starter with a smack pack is mostly pointless as there isn't enough sugar in a 1L starter for the yeast to multiply much. I usually do a 1.5 - 2L starter plus the mini starter and I've never had an issue .

Also no need to let your starters "ferment out". I leave mine for about 18 hours before going in the fridge since that's about when the yeast start to produce alcohol and stop multiplying except for cell replacement.

Always use a 10 to 1 ratio of water to DME. 1L to 100grams etc. That will give you a gravity of 1.040.

 

100g of DME in 1000ml of water should give you a gravity of about 1.037

 

Read through this experiment and judge for yourself if a 1 liter starter is sufficient or even necessary.

http://sciencebrewer.com/2012/03/02/pitching-rate-experiment-part-deux-results/

 

Correct, sorry, I was rounding slightly. .003 gravity points in a starter makes little difference imho

 

I wouldn't really take one experiment with a particular strain as definitive of good yeast practices, especially if you're not using that strain. One of the main reasons to be able to do starters is that when you start to hone in on a recipe, pitch rate becomes a factor with many strains and under pitching may not be optimal--though it may also be optimal. The idea that there's one correct pitch rate is totally wrong, as evidenced by the widespread differences we find in many of the best breweries in the world.

Also, lagers.

 

It makes a difference of ~20 billion cells in a typical 2 liter starter. Probably not enough of a difference to matter under most circumstances. But there could be some cases (overbuilding a starter to harvest yeast, for example) where it might matter.

 

Quite the experiment. My palate isn't the most sensitive, is this basically just saying that a one or two liter starter doesn't matter to someone like me?