Inflating Liquid Yest

[MikeB.]

Hi All,

I stupidly left a liquid yeast packet out of the fridge overnight which now looks to have inflated. I’ve put back in the fridge but will this still be ok to use?

 

[Deadhead]

Should be okay. I'd make a starter though :-)

 

[MikeB.]

Fingers crossed it still does it’s stuff, will however make sure I’ve a back up option just in case

 

[Northern_Brewer]

Fingers crossed it still does it’s stuff, will however make sure I’ve a back up option just in case

If it was OK when in the fridge - not massively out of date etc - then it will be fine. Yeast is tough - in the wild it has to spend a Mediterranean summer in the bark of a grapevine or whatever, waiting for some fruit to appear in autumn. OK, domesticated yeast have gone a bit soft compared to that, but not a lot softer. Ale yeast typically grow best at ~30C (we only ferment lower to avoid off-flavours), and don't start dying until it gets over 40C - a bit of room temperature at this time of year won't hurt them.

And I've rescued liquid yeast that was 4.5 years past best-before date in the past.

That said, it's not a bad plan to do a quick vitality starter on brewday with a lot of liquid yeasts - particularly the 100bn cell packs - just as a routine thing to get them up and running, you can do it with a portion of the wort after it has first boiled.

 

[MikeB.]

It’s was perfectly ok in the fridge and well within date. Is it normal to inflate when warm?
I’ll prep a starter for when I’m going to use it.
Thanks for all the comments and advice.

 

[JockyBrewer]

I’m assuming it’s a Wyeast packet?

Yeah it’s normal. Sometimes some of the nutrient in the snack pack escapes and causes a bit of activity, particularly when warm. Nothing to worry about.

 

[MikeB.]

I’m assuming it’s a Wyeast packet?

Yeah it’s normal. Sometimes some of the nutrient in the snack pack escapes and causes a bit of activity, particularly when warm. Nothing to worry about.

Hi, it is Wyeast, I won’t panic, still think I’ll go for a starter just in case