Advice please - My first yeast starter with a stir plate

[Michael Burnley]

Hi,

I intend to brew tomorrow, and yesterday I made a 2 litre liquid yeast starter that is still on the stir plate and looking active (foam has appeared on the surface), by pitching time tomorrow it will have been on the stir plate around 48 hours.

So do I keep this on the stir plate until it's time to pitch tomorrow and do I throw the whole 2 litres in ?

Many thanks

 

[Oneflewover]

Hi,

I intend to brew tomorrow, and yesterday I made a 2 litre liquid yeast starter that is still on the stir plate and looking active (foam has appeared on the surface), by pitching time tomorrow it will have been on the stir plate around 48 hours.

So do I keep this on the stir plate until it's time to pitch tomorrow and do I throw the whole 2 litres in ?

Many thanks

I think that accepted practice is to chill the starter to precipitate out the yeast then pour out most of the liquid before swirling round and pitching. I generally do this but I have also pitched the whole thing with no discernible issues.

 

[cushyno]

If the yeast is done earlier, sometimes 36 hours is enough, put the vessel somewhere cool or cold crash it to let the yeast drop to the bottom. Pour off as much clear liquid as you dare, then pitch the rest.

Try to let the yeast come gradually back up to fermrnting temperature before pitching

 

[Brew_DD2]

I think that accepted practice is to chill the starter to precipitate out the yeast then pour out most of the liquid before swirling round and pitching. I generally do this but I have also pitched the whole thing with no discernible issues.

This how I do it. I prefer to decant the spent wort off. I just don't like the idea of over a litre of oxidised liquid going into the beer.

 

[BeerCat]

Save the decanted wort in a coke bottle and use it for the next starter.

 

[Brew_DD2]

Save the decanted wort in a coke bottle and use it for the next starter.

I'm maybe missing something, but why would you do that? The sugar has been consumed.

 

[RichardM]

I usually make 1 litre starters and leave them on the stir plate until I am ready to pitch and then just chuck the whole lot in, sometimes that has included the stir bar! I haven't noticed any ill effects

 

[Michael Burnley]

If the yeast is done earlier, sometimes 36 hours is enough, put the vessel somewhere cool or cold crash it to let the yeast drop to the bottom. Pour off as much clear liquid as you dare, then pitch the rest.

Try to let the yeast come gradually back up to fermrnting temperature before pitching

I know this is a silly question but how do I know when it's finished ?

 

[cushyno]

You could measure with a hydrometer.

If the starting gravity of your starter is 1037 and expected yeast attenuation is 75%, doing the maths of 37*(1-0.75)= 9.25, means you should expect the starter to be finished when it reaches about 1009. Of course the range of attenuation may vary so give or take point. It depends on the yeast.

 

[BeerCat]

I'm maybe missing something, but why would you do that? The sugar has been consumed.

You decant of the wort in a coke bottle then let that setlle, decant and use it for the next starter. If you have a couple of liter starter there should be enough in suspension for the next brew. Saves throwing away yeast if your in a rush.

 

[RichardM]

You decant of the wort in a coke bottle then let that setlle, decant and use it for the next starter. If you have a couple of liter starter there should be enough in suspension for the next brew. Saves throwing away yeast if your in a rush.

So you are saying recover some yeast from the wort to use in the next starter? I read your original post as suggesting that you reuse the wort from the starter, but as @Brew_DD2 said, the sugar in that has been consumed so it won't be any use as wort in another starter.

 

[Brew_DD2]

You decant of the wort in a coke bottle then let that setlle, decant and use it for the next starter. If you have a couple of liter starter there should be enough in suspension for the next brew. Saves throwing away yeast if your in a rush.

Gotcha!

 

[trueblue]

The length of time it has been on the stir plate there is no reason to believe it is not ready take it off the plate and let it stand somewhere cooler for at least a few hours to settle. A great tip is 10 mins into the boil rack off around 1lt from the boil and crash cool. When down to around 20c pour off the spent wort from the starter and add the fresh wort to the yeast and return to the stir plate. By the time the boil has finished and the wort cooled the yeast will have really woken up and is gagging to munch wort. This will reduce your lag time and is a general good practice to keep the yeast happy and happy yeast equals good beer.

 

[Edison]

This directly off the White Labs website:

”You probably won’t see any visible activity, but the yeast is busy taking up the oxygen and sugars in the solution and growing new cells. After 18 hours, the yeast will have consumed all of the nutrients and oxygen in the starter. Switch off the stir plate or discontinue shaking and it will form a milky white layer on the bottom of the container as the yeast flocculates. If you are not planning on pitching the yeast right away, you can store it in the refrigerator with the foil still in place.

“When you are ready to brew, decant off most (80%) of the clear liquid from the top, being careful not to disturb the yeast layer below. Once the yeast and your wort are at approximately the same temperature, rouse the starter yeast into suspension with the remaining malt solution and pitch the yeast slurry into your wort.”

Im brewing on Monday so will be doing my starter this morning, 18/24hrs seems fine to me in the past. I usually cold crash to drop the yeast out but I may leave it at room temperature and see if it starts falling out on its own, I wonder if it will stress the yeast out less?

I like Trueblue’s idea of waking it up again, in the past I’ve decanted off as much spent wort as I can then add a litre of my new wort once it has chilled in the kettle and put it back on the stir plate to re-suspend the yeast. Once the wort is in the FV and oxygenated I add it back. Fermentation starts very quickly and I see bubbles from the blow off tube within a couple of hours.

 

[trueblue]

I like Trueblue’s idea of waking it up again, in the past I’ve decanted off as much spent wort as I can then add a litre of my new wort once it has chilled in the kettle and put it back on the stir plate to re-suspend the yeast. Once the wort is in the FV and oxygenated I add it back. Fermentation starts very quickly and I see bubbles from the blow off tube within a couple of hours.

You will be surprised how much of a kick start this gives the yeast. I pitched a starter of WLP002 yesterday around 4 PM had a check before I went to bed around midnight it was not just up and running it was trying to climb out of the FV.

 

[Edison]

As of 1330, Wyeast London III spinning away. I'll switch it off in the morning when I start brewing and hopefully it'll be settled out to decant when my kettle has cooled.

 

[Edison]

Switched off the starter this morning after 18hrs and it looked like this:

Left it at room temperature and when I was ready to pitch 6hrs later it looked like this:

Seems like Wyeast London III doesn't need a cold crash to floculate out.

 

[trueblue]

Personally I give it longer to settle. I will turn the stir plate off the night before so it is at least 12 hours settling.

 

[Drunkula]

Try to let the yeast come gradually back up to fermrnting temperature before pitching

You don't actually need to do that. It's one of the things that's in one of the yeast labs little videos they do that address issues.

 

[Edison]

Its not very clear on the second picture, but it had pretty much fully settled out. The spent wort I decanted was pretty clear and a definite layer of yeast at the bottom i was able to leave undisturbed. All yeast are different though! I hadn't given myself much spare time on this one though!
I chilled the main wort to 17c with an immersion chiller and gave it 30 minutes to settle out, then decanted and added 1l of new wort to the flask and stired it while racking and oxygenating.

OG 1.058, 14brix at 1400. I shall report back tonight what we have by bed time!