How much should my starter attenuate?

[klnosaj]

I'm having really bad luck with a batch of old yeast I bought. I'm on my 3rd smack pack and still haven't been able to get a 500ml starter to start. But it has me thinking...how much will a starter attenuate? If the SG of the starter wort is 1.040 around where will it finish? Right now I can't a reading to budge but I'm curious what it should look like.

 

[lamppa]

should be around 1.010, but it depends on the strains expected attenuation rate.

 

[klnosaj]

should be around 1.010, but it depends on the strains expected attenuation rate.

So it should ferment out all the way, then. Huh. I don't know why that surprises me. Thanks for reply.

 

[TarheelBrew13]

It is my understanding that you don't want to let your starter finish before pitching or at least stalling fermentation by cold crashing. You are trying to get the yeast cells to multiply in a hospitable environment. Yeast cells will usually finish multiplying in the first 24 to 48 hours but your starter is unlikely to reach complete attenuation by then. Most people I have spoken with recommend cold crashing the starter at high krausen. I wouldn't go beyond 48 hours though before pitching/cold crashing.

 

[klnosaj]

Yeast cells will usually finish multiplying in the first 24 to 48 hours but your starter is unlikely to reach complete attenuation by then....I wouldn't go beyond 48 hours though before pitching/cold crashing.

http://www.youtube.com/watch?v=ng0Ib7n4DIA

This would be all well and good if I could get the starter to start in fewer than 3 days. Others have had no problem using 6 month old yeast. As for me, I can't get it to do anything useful at all and I've waited as long as 6 days on one batch.

 

[william_shakes_beer]

What is your starter temperature, and are you using a stir plate or shaking periodically? I did a starter on a stir plate this past week using Nottingham yeast I had harvested from a split starter. 24 hours, no activity at all. Went to bed fully expecting to pitch another sample of the same yeast in the morning. In fact, I even went so far as to pull a sample out of the frige to warm up to room temperature. In the morning, I saw a tiny bit of foam on the top. Heartening. let it go, when I came home from work that evening i had a nice 1/2" krausen on top. Stayed actively fermenting for 48 hours. If I was not using a stir plate I can see the same starter taking much longer.

 

[klnosaj]

What is your starter temperature, and are you using a stir plate or shaking periodically? I did a starter on a stir plate this past week using Nottingham yeast I had harvested from a split starter. 24 hours, no activity at all. Went to bed fully expecting to pitch another sample of the same yeast in the morning. In fact, I even went so far as to pull a sample out of the frige to warm up to room temperature. In the morning, I saw a tiny bit of foam on the top. Heartening. let it go, when I came home from work that evening i had a nice 1/2" krausen on top. Stayed actively fermenting for 48 hours. If I was not using a stir plate I can see the same starter taking much longer.

I usually start my starters in the mid 70's. I've made dozens of them without problem until I bought this most recent batch of yeast. Others who bought from the same source say they've had no problems. Right now I'm waiting on a Thames Valley that's been at room temp for 2 1/2 days and undergone intermittent shaking. I got nothing. Maybe it's still in lag. But the longer it sits without beginning fermentation the greater the chance is of bad bugs finding a way in. I waited 6 days on one starter and then it got colonized by the nasties.