RIS pitching rate

So i'm in the process of planning a Russian Imperial Stout and was trying to figure out how much yeast to pitch. This is my first go round with making a starter and all that jazz so please bear with me.

The OG is around 1.080 which according to mr. malty says I'm going to need ~270 billion cells. So I'm thinking about using a 2L starter for one smack pack which will give me 200 billion cells. First question, would just pitching this starter by itself be enough or will that put too much stress on the yeast?

All I have is a 2L flask so would I not be able to step it up any bigger (I think?). So I was leaning towards buying an extra smack pack and throwing that in there along with my starter which would give me 300 billion cells, definitely adequate. Which leads me to another question, could I just throw both smack packs in the original starter, leave it for awhile and call it good? I'd like to not have to buy an extra pack if possible but will obviously do so if it means a better final product.

Onoce again please excuse my ignorance but I'm still learning about starters and stepping them up.

Look up step starters. Basically make your starter to get 200 billion cells, crash in fridge overnight or longer. Decant that off and pitch the crashed out yeast into another starter which will get you up to your pitching rate.

So I can throw another smack pack in my original starter and I will be all set?

No, it's not needed if you have the time to do another step with you original smack pack/starter. Use yeastcalc.com to tell you what size step starters you would need to get up to your correct pitching rate.

Agreed with the stepping up and with using yeast calc to help with that.

I am lazy and just buy a few packets of dry yeast. For high gravity I will dehydrate and pitch. You can get almost 3 packs of dry for the cost of liquid and have a 100% pitchable quantity. That is unless you want a specific yeast for this beer.....

Ok so I'm getting a little antsy to brew, ingredients came yesterday, wanted to brew today but instead I'm making a starter with a smack pack. Going to let it sit on a stir plate for 24 hours. Then tomorrow (brew day) I'm going to try to step it up. Will the 6-7 hours of brew day be enough time to get a high enough cell count? Or should I toss in another pack of yeast to be on the safe side?

Yes -- the 6-7 hours should be long enough. I just brewed a stout with OG 1.080 this weekend. Made a starter of 1 cup DME boiled in 4 cups water, pitched 1 vial of White Labs Irish Ale the morning of the brew. About 10 hours later I pitched the whole lot of it into my beer. Fermentation extremely active the next morning. (Came home the following day to beer splatter all over the bathroom, but that's another story).

Wouldn't you have been short 100 billion cells that way hercher?

I was thinking about splitting my current starter in two and then going at it again to get me to approx 400 billion cells. 200 billion cells in my current starter split in two = 2 100 billion cells. add 1 cup of dme and 4 cups of water to each to get me to 200 billion in each = 400 billion cells total. (probably an overestimate but i only need 375 billion cells).

I know underpitching isn't the end of the world but I'm making an effort to correctly pitch from now on and see if I can see a difference.

oh wow, so after rereading my original post and going to mr malty to confirm, I don't need 375 billion but 273 billion cells. Not sure why I thought the former but glad it's the latter. Disregard most of what I was saying. Wish I could say I was drunk for these postings but I wasn't.....

I had the setting on Mr malty on simple starter and not on stir plate. Had no idea a stir plate saves so much space. So my 2L flask will be plenty for this beer as it's telling me I only need 1.5L of a starter to get there. Thanks for all the help. :rockin:

I like to over pitch my stouts and IPA's to give me a better chance of them finishing dry enough (I'm not AG), but I under pitch my Belgians to stress the yeast. You can make a 2L starter without any ill effects.

jack_a_roe said:

Wouldn't you have been short 100 billion cells that way hercher?

Click to expand...

Perhaps. I didn't go to Mr. Malty, which tells me that I was about 1.4 liters short. I guess the proof will be in the pudding when I taste the beer. I take the short lag time and very vigorous start as evidence that I didn't significantly underpitch.

I've been averaging 85-90% apparent attenuation lately (since I started calculating) with my method, using WLP 565 and 007. This batch I used WLP004.

I will, however, for my next batch, attempt to use the proper sized starter.

no i think you were right, or at least a lot closer than i thought. i was using those wrong numbers that were off by 100 billion so you were right there.