Failed yeast starter - what went wrong?

[eddiewould]

Hey Guys,

I made my first yeast starter the other day. Started it on Wednesday evening. I boiled 200g of light DME and 2L of water in my flask (with stirbar), covered with aluminium foil for 20 minutes (I boiled a tsp of US-05 yeast to try and give some nutrients). I cooled it down in the sink (swirling to distribute the heat) until it was just luke-warm to the touch.

I then shook the flask to aerate, added the packet of Wyeast 1968 through a sanitised funnel and set my stirplate going in my fermentation chamber at 22c.

The pack had been "smacked" a few hours earlier, but it didn't really look as though it had swollen. The yeast has a manufacture date of 10th Dec 2013 but the LHBS guy said it would be fine as long as I made a starter.

I turned off the plate and set it to "cold crash" Friday morning. It's now Saturday morning. There's a small layer of yeast at the bottom of the flash, however I poured off the wort on top and measured the gravity and it's still 1.040 which indicates to me that my yeast are dead or extremely lazy

The good news I guess is that it tastes fine, so presumably my sanitation is fine.

I'm brewing today so I'll have to buy two smack-packs from another shop and hope for the best I guess. But would be good to know where I went wrong.

 

[Hermit]

Sounds to me like you bought a package of dead yeast. You brew shop owes you.

 

[Kingbogart]

That process sounds correct.

Many times when using older yeast, you need more time and a less stressful environment. Making a small 1.020 starter and giving it a couple days to see if it's viable, then stepping up into a 1.040 can help nudge it along. I made a starter off of one package of old wyeast that didn't show viability for about 4 days.

 

[MindenMan]

I often revive very sleepy yeast. I use a 1.010 or so wort gravity to start, and step the gravity up 3 or 4 more times, sometimes taking a few days in the process.

 

[Gameface]

For yeast that old it typically going to take a couple starters to get where you want.

 

[HamiltonBrian]

This is the exact issue I've run into with my latest vials of WLP023. No activity. I've cold crashed my last vial after letting it rest on the stir plate for 48 hours. I'm crossing my fingers for the use of it in my batch tomorrow.

 

[duboman]

You expected too much from almost year old yeast. Had you started with a lower gravity 1L starter, decanted and stepped up you'd have been more successful

The fact that you had a small layer of yeast tells me it wasn't dead( I'll assume this layer was larger than what was in the pack)

My bet is if you had decanted and stepped again it most likely would have taken off better then


Sent from the Commune

 

[Yooper]

Next time when you start with old yeast, give it more than 24-36 hours on the stirplate. It's alot to expect to have it wake up, reproduce, ferment the starter, and then be ready to be cold crashed in less than 36 hours!

It may take 3-4 days to get going, but once it does it would be fine.

 

[dinnerstick]

in addition to the good advice above, i'll add that 1968 is a super high flocculator. when it's done it sinks like an anchor (actually looks like cottage cheese being stirred in water), the cleared in your flask will be much clearer than in your pics even without cold crashing.
also you don't need to keep your starter at cooler fermentation temps, they will go a lot quicker if you let them get to 30 or so; you're decanting off the nasty smelling hot beer anyways and the tiny bit that remains will not be evident in your final beer.

 

[eddiewould]

Thanks for the advice guys. Will put it down to experience. The beer is happily fermenting away with the two packs of 1728 I pitched directly.