Saq the Pious AG kit and wlp530

[mboardman]

planning to brew the Saq kit (its a Westy 12 clone) tomorrow and not sure how much yeast I should pitch. 5 gallon batch, OG 1.090. I have 3 packs of wlp530, all three manufactured back in Jan 2019. Mr Malty says the viability is around 10%, so I would need 11 packs with a starter on a stir plate. Obviously, Im not doing that, but curious what everyone thinks or if anyone has had experience pitching older WLP yeast?

I began the starter with one pack, then this morning, concerned I would be underpitching due to the age of the packs, I added a second. Should I add a third?

 

[jfolks]

According to brewers friend you have 0 viable cells. I’m sure something’s alive, but doesn’t seem worth the risk given the high OG. I would hold off on brewing this until you get some new yeast. Go to your local homebrew store and buy any Belgian Trappist yeast - shoot for 350 billion cells. If buying online, buy 2 packs of Safbrew BE-256 Dry Yeast

 

[kh54s10]

The calculator I use says you have 26% viability and if you make a little over 2 liter starter on a stirplate you only need one pack.
http://www.yeastcalculator.com/ I use the K. Troester stirplate calculation.

 

[isomerization]

I think you’ll be fine, don’t look too much into the starter calculators. I don’t know how the yeast packs were stored, but there’s very likely plenty of viable yeast left.

Use the visual cues from your starter. Once it turns milky in color it’s probably done fermenting. If you don’t get a solid mat of yeast after cold crashing, then you can be concerned.

 

[IslandLizard]

You should be fine with pitching the 2 packs in the starter, no need for the 3rd.
But... 24 hours for a stirred starter may or may not be enough with 5 month old yeast. As @isomerization said, I always wait for the color change, it turning from dark to milky which sometimes take a few days. Then give it 24-36 hours after that. It usually gets milkier and thicker.

WhiteLab's PurePitch packs tend to hold viability better over time, as much as 90% during the first 3 months, so there's that advantage. Your yeast calculator doesn't know that and may be a bit pessimistic.

If you have pure oxygen, you can really boost that starter during the 4-8 hours before pitching. Bubble oxygen for 2-4 minutes at a low rate, 1/8-1/16 l/m. Then just swirl it from time to time, don't stir continuously, it knocks the oxygen out. Warmer temps speed up starter growth, 80F or even a higher (up to 95-100F). Then chill to wort temps and pitch.

 

[kh54s10]

You should be fine with pitching the 2 packs in the starter, no need for the 3rd.
But... 24 hours for a stirred starter may or may not be enough with 5 month old yeast. As @isomerization said, I always wait for the color change, it turning from dark to milky which sometimes take a few days. Then give it 24-36 hours after that. It usually gets milkier and thicker.

WhiteLab's PurePitch packs tend to hold viability better over time, as much as 90% during the first 3 months, so there's that advantage. Your yeast calculator doesn't know that and may be a bit pessimistic.

If you have pure oxygen, you can really boost that starter during the 4-8 hours before pitching. Bubble oxygen for 2-4 minutes at a low rate, 1/8-1/16 l/m. Then just swirl it from time to time, don't stir, it knocks the oxygen out. Warmer temps speed up starter growth, 80F or even a higher (up to 95-100F). Then chill to wort temps and pitch.

I agree with all of this except for the 24 to 36 hours after it getting milky. If it is fully milky the yeast have already reproduced and now are spending precious energy on turning the starter wort to alcohol.

IMO, it is better to pitch when the starter is at high krausen and the yeast cells are healthy and energized. I cold crash it then, pour off the starter "beer" then warm to pitching temperature. If it is a small starter I feel it is even better to pitch the whole thing at high krausen. But for bigger ones I don't want that "beer" that was fermented in less than ideal conditions going into my wort.

 

[IslandLizard]

I agree with all of this except for the 24 to 36 hours after it getting milky.

The key is the turning point where it starts to turn from hazy brown to a significantly lighter color. I feel a minimum of 24 hours is needed after that to get it really looking like a milkshake. 12 hours doesn't seem to do it. This is at 64-74F ambient temps.

 

[IslandLizard]

Let me add, when the starter is thick and milky I cold crash for 1-7 days (depending on the strain), decant, save some or most of the slurry. Before I brew I make a 1 liter vitality starter with some of it (using pure oxygen doping) that gets pitched whole. I usually see bubbles 4-8 hours later.

 

[kh54s10]

The key is the turning point where it starts to turn from hazy brown to a significant lighter color. I feel a minimum of 24 hours is needed after that to get it really looking like a milkshake. 12 hours doesn't seem to do it. This is at 64-74F ambient temps.

OK, the extra 24 - 36 hours is not from when it is fully milky, but it is to get fully milky. I agree in that case.

I do step starters from a vial of frozen yeast that contains only 5 ml of yeast to start from. I run each step only 18-24 hours. It has never failed to work in that time frame. At the end of 3 steps I usually have 1/2 inch of yeast slurry after cold crashing. Roughly the same as a starter using a fresh pack of yeast. Again 18 -24 hours has always worked. Though I haven't started from 6 month old yeast packs.