Liquid yeast survival

[Keruso]

I bought three packs of liquid yeast from MM this week, I ordered the cold packs too. DPD were meant to deliver today, Friday 15/5, but I just got a text to say they are delayed and have cancelled today’s delivery and will try again on Monday. This means the yeast will be sitting in a warehouse or a van over the weekend. Will this kill the yeast completely ? I don’t know what temperature it will be exposed to..

 

[MyQul]

It shouldn't kill it completely (Yeast is hardy stuff, I've cultured up 40+ year old yeast from Jubilee ale bottles before) but you'll certainly want to make a starter

 

[Keruso]

It shouldn't kill it completely (Yeast is hardy stuff, I've cultured up 40+ year old yeast from Jubilee ale bottles before) but you'll certainly want to make a starter

I’m really p#ssed off, I’ve never used liquid yeast before, I have bought DME and a flask to make a starter so that was always the plan, perhaps I’ll assume 70% viable cells remain and use a calculator for the starter, cheers for your help.

 

[MyQul]

There are calculators that calculate viability from BBE date but with any yeast calculator there's a lot of guess work involved. I just eyeball how much yeast I have in a starter nowadays.I know how much yeast will ferment my 10L of wort based on how much is in my starter DJ

 

[peebee]

I've just replied to a "yeast" question >here<.

Might be useful? As @MyQul says, the calculators are just guesswork and shouldn't be seen as anything more than a guide. Your yeast will start up fine, and in time you'll figure there's far more messing up your yeast "calculations" than a few days sitting in an unheated warehouse.

 

[nixhaz]

I had a packet of liquid yeast sent with an order a while back. It was a freebie, so I didn't realise it was in the box, which I opened about a week after receiving. It's perfectly fine. I did a starter with it just to be sure though.

 

[Keruso]

I've just replied to a "yeast" question >here<.

Might be useful? As @MyQul says, the calculators are just guesswork and shouldn't be seen as anything more than a guide. Your yeast will start up fine, and in time you'll figure there's far more messing up your yeast "calculations" than a few days sitting in an unheated warehouse.

Thanks, brewunited calculator suggests making a single stage 1.5 litre starter to give more that the required number of cells for my planned brew. Having never done it before that what I planned to do for the first attempt.

 

[peebee]

Thanks, brewunited calculator suggests making a single stage 1.5 litre starter to give more that the required number of cells for my planned brew. Having never done it before that what I planned to do for the first attempt.

If it's a newish pack (which I guess it is) go for it. A single step starter is much simpler than a multi-step starter which gives more opportunity to go all wrong. 1.5L? Not using a stir-plate? But should be done in 18-24 hours. If not using a stir-plate any bubbles might suggest it is done (you are only encouraging yeast growth in the starter, not fermentation of the starter). If using a stir-plate you may not see the bubbles:


Little story from my last starter ... 3 days in to a 4 step starter and the starter was showing signs (bubbles, but I do use a stir-plate but it was off at that time). Woke on the morning of the 4th day and the 4th step starter looked completely dead. In the afternoon, still no sign of bubbles. On a hunch, I checked the SG of the starter. The yeast hadn't just finished its growth, but it finished all the available sugar over-night! The starter was chilled, the used portion decanted off (not essential) and the remaining yeast allowed to warm back to room temperature before being flung into the beer next day. It started in two hours. I may have "over-cooked" it?

 

[Northern_Brewer]

Remember that yeast have evolved to survive on eg grapes in a Mediterranean vineyard through a Mediterranean summer, they're pretty tough.

In fact the optimal growth temperature for most strains is around 30C and lager yeasts will survive into the mid-30s, ale yeasts up to 40C or so - it varies a bit from strain to strain. And kveiks even more. We only brew at temperatures below the optimum to avoid off-flavours. I know it's warm for the UK at the moment, but we're nowhere near the kinds of temperatures that would be a threat to yeast survival, you may lose a bit of viability though and a vitality starter is always a good idea even with "fresh" liquid yeast.

Still, it's a good idea to try and time orders of liquid yeast so that they get dispatched Monday-Wednesday, to reduce the risk of something like this happening. Obviously that's more difficult at the moment given the strain the retailers are under right now.

 

[trueblue]

At least you bought from a source who have a quick turn around. I have been buy from there for years and they are always well within dates.

 

[Keruso]

If it's a newish pack (which I guess it is) go for it. A single step starter is much simpler than a multi-step starter which gives more opportunity to go all wrong. 1.5L? Not using a stir-plate? But should be done in 18-24 hours. If not using a stir-plate any bubbles might suggest it is done (you are only encouraging yeast growth in the starter, not fermentation of the starter). If using a stir-plate you may not see the bubbles:


Little story from my last starter ... 3 days in to a 4 step starter and the starter was showing signs (bubbles, but I do use a stir-plate but it was off at that time). Woke on the morning of the 4th day and the 4th step starter looked completely dead. In the afternoon, still no sign of bubbles. On a hunch, I checked the SG of the starter. The yeast hadn't just finished its growth, but it finished all the available sugar over-night! The starter was chilled, the used portion decanted off (not essential) and the remaining yeast allowed to warm back to room temperature before being flung into the beer next day. It started in two hours. I may have "over-cooked" it?

Thanks for your help, I am using a stir plate, it’s meant to arrive from Amazon early next week, I was going to do the starter on next Friday for a Sunday brewday.

 

[Keruso]

Remember that yeast have evolved to survive on eg grapes in a Mediterranean vineyard through a Mediterranean summer, they're pretty tough.

In fact the optimal growth temperature for most strains is around 30C and lager yeasts will survive into the mid-30s, ale yeasts up to 40C or so - it varies a bit from strain to strain. And kveiks even more. We only brew at temperatures below the optimum to avoid off-flavours. I know it's warm for the UK at the moment, but we're nowhere near the kinds of temperatures that would be a threat to yeast survival, you may lose a bit of viability though and a vitality starter is always a good idea even with "fresh" liquid yeast.

Still, it's a good idea to try and time orders of liquid yeast so that they get dispatched Monday-Wednesday, to reduce the risk of something like this happening. Obviously that's more difficult at the moment given the strain the retailers are under right now.

Good advice, I was expecting delivery sooner than today but of course right now it’s going to be more difficult. I’ve always found MM and DPD to be ultra reliable so no complaints