Yet another yeast starter question...

I have been searching for the last hour or so and have not been able to find a thread that fits.

I made my second starter last night.
My first was a couple of weeks ago. I got 2 smack packs that had gotten warm and swelled some in shipping. I put them in the fridge immediately. The first was 1056 American Ale. The next morning on the stirplate I could see the yeast swirling and some bubbles rising.
My second is NB NeoBritannia. Overnight it may have done all it's thing?? No bubbles rising.

My question is how do you determine if the desired amount of yeast cells have been produced? I let it settle and I do have a nice layer of yeast, but, not having let a smack pack settle I do not know how much would be there originally. I have about 1/4 inch on the bottom of a 2 liter flask. I poured off most of the wort and started a second run. I saw the link to the Wyeast site and their picture of vials but have no reference to quantity there or how to relate it to my flask.

I want to brew a Nut Brown Ale extract Kit tonight or tomorrow morning but have no backup yeast available.

You should have plenty in that 2L flask... you have way more yeast solids in there than in a smack pack. If you are adding more wort into it now it should be perfect to do a high krausen pitch if you brew tonight.

Check the FG of the wort. If it's low and holding, the yeast won't be multiplying anymore.

There's no really easy way to tell how many billions of cells there are. Best we can do is use a calculator like Mr. Malty, which (I think) takes known reproduction rates for yeast in starter wort and applies those rates to the quantity of starter wort.

In other words, I guess Mr. Malty knows that yeast in X liters of starter wort will reproduce until it has Y billion cells and then stop reproducing.

Anyway, sounds like you're on the right track with your starter. Cheers!

RiverCityBrewer said:

You should have plenty in that 2L flask... you have way more yeast solids in there than in a smack pack. If you are adding more wort into it now it should be perfect to do a high krausen pitch if you brew tonight.

Click to expand...

Thanks, Having no reference as to the amount of yeast solids in a smack pack I was not sure if any cell multiplication had taken place.

Now to work. I'm bottling my first batch: an Irish Red Ale that got too warm on the first 2 days fermenting so it has been in secondary for a month. The second batch - PatersBier was bottled last week. Third batch - Extra Pale Ale is in primary. Will brew the Nut Brown Ale tonight.

Is 20 gallons of beer enough for mostly myself?? I may share a little...

I've got a similar issue right now, a couple of White Labs vials came really hot. I've already brewed with one of them, having made a starter that was slow to take off but eventually did. The actual pitch into the brew had a nice short lag time, but then again it was a 3-gallon batch and an average gravity beer.

The other one, I have the starter going right now, and it's not been doing that great... it looks like it had a small kraeusen that I missed, but not a whole lot. And it took nearly 4 days to do that. There does appear to be a fair amount of settled yeast, I think, so that's good. Most concerning of all, though, this is going in an IIPA with a target OG around 1.080-1.090. So I'm a little worried... should I decant this starter and pitch into another starter to step it up, maybe?

Follow up:
I brewed the Nut Brown Ale and pitched the starter to which I had added more wort. I think it was in high krausen when pitched. Anyway, pitched late that evening and had active fermentation when I got up the next morning. Now the Nut Brown Ale which turned out great is already half gone.

I brewed a Northern Brewer Speckled Heifer partial mash kit yesterday and pitched harvested American Ale yeast from a starter last night. It took longer to start than I expected. But, tonight it is showing signs of fermentation. This one should be ready in about 4-5 weeks.