[northarrow]

I received a Northern Brewer ingredient kit for Christmas from my wife.  It shipped with a Wyeast 3538 Leuven Pale yeast pack with the standard refrigerate ASAP package.  Unfortunately, my wife left the gift in a spare room for about a month without knowing that the yeast should be refrigerated,  I'm now trying to get a starter going, and it doesn't seem to be taking off.  It's been 18 hours or so.  Is the yeast DOA?

[Slowbrew]

I wouldn't say it is a goner but the starter may  take longer than you're used to.  If you aren't using a stir plate (I don't have one but they were all rage last year) swirl the jar a coupel of times a day.  If you don't see any activity in 48 hours I'd be picking up some new yeast.

Paul

*** edited to fix typo... again.

[bigchicken]

I've used a Wyeast pack over 8 months old with good results. I had the pack refrigerated, so that helped it I'm sure. It never appeared to do much of anything when I made a starter, but I tasted it and fermented out. I'd say it took over a week. I would have made a 2nd starter, but ran out of time. The yeast did so well it came out the airlock with a healthy blowoff. It climbed out of a 6.5 gallon bucket on a 5 gallon batch. I'd recommend giving it a few days and then checking the gravity or giving it a taste test. That yeast may surprise you yet.

[reverseapachemaster]

I wouldn't assume it's dead. Remember, yeast stay active and alive in your beer at room temperature for weeks, even months depending on how you store your beer and how long it takes for you to consume it. Yeast live in the wild in conditions far less hospitable.

Give it some time. Add some yeast nutrient if you have some. Continue to aerate well. It will likely come around.

[woodlandbrew]

Viability doesn't drop much in a week out of the fridge, but I've never tried a month.  It could work, but will take some time to get going.

http://woodlandbrew.blogspot.com/2012/12/yeast-health-when-kept-at-ambient.html

[narvin]

How are you checking yeast health?  From what I've read, the methylene blue stain is not accurate below 95% viability.

[woodlandbrew]

How are you checking yeast health?  From what I've read, the methylene blue stain is not accurate below 95% viability.

I've read that too.  It is "not accurate" to some level.  Even the American Society of Brewing Chemists calls it not accurate.

If by "not accurate" you mean that it is not exact then I agree.  There is some error, but that error can be determined so that the accuracy is known.

It is very dependent on the strain and how much Methythele Blue that is used.  WLP004 and WLP566 stain just fine with 0.03% MB, but EC-1118, and WLP650 are better with 0.06% and 0.1% respectively.  It's also very dependent on the operator.  MB staining is very difficult to use on some strains, and there doesn't seem to be one concentration that works for every strain.  If you use too much it will actually start to kill some of the weaker yeast cells.  The method isn't perfect, but it has it's place.

I have a blog post on this coming up. 

[northarrow]

Update:  The starter, after a couple of days, still looks fairly anemic.  It started to settle out overnight, so I put it in fridge when I got up.  Since I had planned today to be a brew day, I'm just going to go ahead with the plan.  I will decant the starter and just pitch it.  We'll see what happens.  It will be a good learning experience nonetheless.

[woodlandbrew]

The lag phase can be pretty long, especially if the yeast has come out of stressful conditions.  You aren't going to see much activity until the exponential growth phase.  Here is some observations I recorded recently when propagating some low viability yeast directly following a fermentation.  It took about 12 hours to start, but 2 days would not be uncommon. 

http://woodlandbrew.blogspot.com/2012/12/yeast-cell-growth-observations.html

Your plan to stay the course sounds good.  You will want to aerate well.  Pouring the wort between two buckets or a kettle until the foam is threatening to come out of the bucket will ensure that you are at the saturation point of O2.  That will yield 8-9 ppm of O2 which should be plenty unless your OG is above about 1.050

[northarrow]

Very pleased with the way things worked out.  After pitching the starter on Sunday, nothing was happening for the first 24 hours or so.  Then I checked and it had really taken off.  A beautiful krausen has developed, and the activity is what I would expect.  Looks like things are on track.

[beersk]

Very pleased with the way things worked out.  After pitching the starter on Sunday, nothing was happening for the first 24 hours or so.  Then I checked and it had really taken off.  A beautiful krausen has developed, and the activity is what I would expect.  Looks like things are on track.

Righteous.  Good to know.

[reverseapachemaster]

Glad it worked out. Yeast are more fierce than we tend to believe/act.