Re-activating old(ish) starter

Hello,

I had a multi-step starter going for a high gravity Tripel then my daughter was born a few weeks early and brewing life has been on hold. Using yeastcalc.com, I was doing 3 2L steps, the yeast pack was kind of old, and had done 2 of them before the jug was placed in the fridge for storage. It has been about 6weeks since I stowed the starter and I should be able to brew again soon so I want to get this thing going again. Do you think I should do just one more 2L addition or 2? How much has the viability dropped since I stored the starter?

3 2L step ups according to my experience is a good thing. It wouldn't hurt to do one more step up and time the activity to be high before you pitch as long as there isn't too much liquid when you bring it to room temps. Can't pitch too much yeast on a high gravity belgian IMHO.

I just used a 1214 smack pack that had a manufacturing date of 11/11 and I smacked it and pitched it into a 2 gallon batch 2 weeks ago and got a little lag time but it was up and attem after 1.5 days. Fermented out fine for a bsda.

Congrats on the new addition to your family. Hope everything is going well with the results of the early delivery.

Personally, I do make starters and high-gravity beers, I don't use yeast calculators, and I've gotten along just fine. Based on what you've said, assuming a 5 gal batch of OG ~ 1.09, I'd say the following:

* Regardless of your cell-count, your yeast are probably a little worn down and could use a good feeding in any case. How do they smell? Visually what do the layers look like? Can you guess the volume of the yeast slurry at the bottom?

* How and when was the starter stored? Did it have headspace/oxygen in the container, and how much? "Experts say" that yeast deplete glycogen reserves much faster in the presence of O2. Was it at high krausen, and did you have to vent CO2 from the starter (or use an airlock)? Along the same lines, what would you guess the SG of the starter was when you put it in the fridge?

* Overall, I'd say don't worry too much as long as it smells ok. Decant off the clear liquid, restart the starter process with 1 or 2 steps, and you should be fine...

Thought I'd follow up on this: I did one more 2L addition to the starter and pitched a few days later. My OG was 1.089 and my last reading was 1.007, so I'm gonna go ahead and say that I had enough good yeast! My tripel tasted a little hot, and at 10.6% estimated abv it should have, but it's sitting in secondary now and hopefully mellowing out.