Wyeast Smack Pack did not inflate

I ordered four extracts from NB and received four Wyeast liquid yeast smack packs. There website specifically recommended against purchasing liquid yeast from them during the summer but I did so anyways.

The yeast/package was shipped on Monday and arrived Friday night, where I immediate smacked two of the packets and put the other two in the fridgerator. The two I smacked that night inflated as normal and I made yeast starters out of them, which I just pitched yesterday.

After pitching yesterday, I took the remaining two smack packs out of the fridge (both are Wyeast 1084 Irish Ale), smacked them, went to a movie and when I came back they were not inflated. I went to bed, and 8 hours later they were still not inflated. I made yeast starters out of them this morning (and verified the inner pouch was punctured), and its been about 8 hours now and there is no activity.

Is it just a coincidence that the two smack packs I used last week right from the UPS package inflated while the two that I had stored in my refrigerator for a week did not?

Main question: Does a smack pack which does not inflate suggest that the yeast died, or rather became unusable?

Topic wyeast smack-pack yeast homebrew

Category Mac

1
answered at

I'd say you were too impatient. There's no reason to assume that the pack will inflate that fast. The ROT is to give it one day for every week past manufacture. So even if the pack was only a couple weeks old, that would have been at least to days for it to inflate. And 8 hours in a starter is too soon to determine there's no activity. The packs might or might not have been OK, but you didn't wait long enough to find out.

1
answered at

I'd say it was the fact you put it in the fridge, which will cause the yeast to go dormant. I usually leave for at least 24 hours if they have been stored in the fridge.

I think the yeast were dormant, not dead, and needed some more time to get up to speed compared to the packs that were not put in the fridge.

If you had left the pack 72 hours and still no result then that does indicate yeast were not viable. But in your case, I think it was simply too little time before pitching into the starter.

Also WLP004 can be a slow starter - I have had lag times in excess of 48 hours with that strain.

1
answered at

A pack that does not inflate could be ok. Some strains are slower to start. But, if you made a starter and there's still no activity, the yeast may be inactive. I wouldn't risk it in my batch. I'd get another pack or 2. Maybe throw in a dry yeast.

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