Expired yeast?

[Tomdeanmiller]

Hey guys
I just started my first ever home brew using a Coopers lager kit, and the kit was one year expired, (I know shame on me) I followed the coopers YouTube video for starting the brew, my OG was 1.040, sitting at 21 degrees. Now a week in to fermentation my SG is now down to 1.012.. if I am reading it right that means my brew is less than 1% alcohol content?? Could this be because of the expired yeast? Should I keep waiting and will it go up? If not, would it hurt to buy some new yeast and add it to the brew to restart fermentation? Sorry total noob here. Thanks

 

[Deadalus]

No, that's not what it means. Subtract the two values and multiply by 131.25 so

(1.040-1.012) x 131.25=3.8% ABV

Now it could still be fermenting but if the reading stabilizes day to day then it's done.

 

[Immocles]

https://www.brewersfriend.com/abv-calculator/

Should be a little under 4%.

 

[Tomdeanmiller]

Thanks!!

 

[THESULLI]

For the future, dry yeast is extremely hardy and can still be pitched well after its expiration date. I pitched a packet the other day that was more than 2 years past it's expiration date with no problem.

Enjoy your beer!

 

[ike8228]

I just bottle two separate batches using the same exact yeast except one was a year expired and got the same exact FG in both beers. I did do a starter the day before to wake them up faster (bubbles within 6-8 hrs verses 24ish). So an expiration is not a end all, but I would be curious just how old is too old before, at least dry yeast, lasts. In my experience always good to rehydrate a start it up at least 20-30 minutes before if not a full blown starter to make sure it is good yeast.

 

[RM-MN]

I've seen study results that suggest that dry yeast loses 1 to 2 % viability per year. After a few years that rate may increase but who wants to extend a study that far. Dry yeast isn't expensive enough to justify a longer study, just replace it if it is over 2 years.