Liquid yeast storage

Badgersack · Mar 14, 2021

I've been given a couple of brew kits for my birthday and the yeast hasn't been kept refrigerated properly (at all).

Will it be alive still? Likely at room temp for a few days.

The yeasts are:
White Labs Midwestern Ale WLP4040
White Labs Framgarden Kveik WLP4051

What's the best way to check it's still alive?

Thanks!

samale · Mar 14, 2021

Make a starter, it will let you know. What is the date on them

Badgersack · Mar 14, 2021

The midwestwern has only 10 days remaining and Framgarden is May.
What do you use for the starter?

phettebs · Mar 16, 2021

Badgersack said:
The midwestwern has only 10 days remaining and Framgarden is May.
What do you use for the starter?

Use dried malt extract at a 10:1 ratio. So you'd add 100g of DME to 1 liter of water. Bring it to a boil. Put it in the sink with an ice bath to cool it down to room temp. Then pitch the yeast. Ideally, you want a stir plate to put it on and keep it in constant motion. But you can just shake it around every time you pass by.

How big a starter you make depends on multiple factors. 1) the age of the yeast pack. 2) the expected OG of the beer you are brewing. 3) the method you use to aerate the starter (stir plate, intermittent shaking, just leaving it to sit)

There are yeast calculators on the web you can use.

Galena · Mar 16, 2021

Maxonian · Mar 19, 2021

I used to regularly buy the out of date lucky dip yeasts from brew uk. Some of them were a few months out date when they arrived. One or two were nearly a year out of date by the time I got round to using them but they all worked fine. I always made a starter though so I echo samale and Galena’s advice. I’d be reluctant to pitch straight into the wort without one.

Alternatively, you could make a small beer with an FG of around 1.040 and harvest the yeast once the beer has fermented. I did this with a Wallonian Farmhouse I strain that was waaaay past its use by date and I’m still using later generations of that yeast in my beers.