# How Long On Stir Plate?



## humulus (6/1/12)

Doing my virgin starter on my stir plate(1st time use too!),done all by the book i hope,2l of 1040ish wort cooled too pitching temp,around 30ml of 2nd gen 1469 was pitched into the wort and put on the stir plate (works like a trooper and cost under $20 to build!)
Question is how long do i leave it on until it is the correct "volume"to pitch into 23l of around 1044wort is the 24hr mark ok??
cheers


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## Crusty (6/1/12)

humulus said:


> Doing my virgin starter on my stir plate(1st time use too!),done all by the book i hope,2l of 1040ish wort cooled too pitching temp,around 30ml of 2nd gen 1469 was pitched into the wort and put on the stir plate (works like a trooper and cost under $20 to build!)
> Question is how long do i leave it on until it is the correct "volume"to pitch into 23l of around 1044wort is the 24hr mark ok??
> cheers



A full 24hrs works perfectly for me.


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## humulus (6/1/12)

Crusty said:


> A full 24hrs works perfectly for me.


Cheers crusty! running in and out of my shed like an expectant Dad! looking at it!
Ill be ready to chill and pitch tomorrow arvo!


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## TidalPete (6/1/12)

humulus said:


> Doing my virgin starter on my stir plate(1st time use too!),done all by the book i hope,2l of 1040ish wort cooled too pitching temp,around 30ml of 2nd gen 1469 was pitched into the wort and put on the stir plate (works like a trooper and cost under $20 to build!)
> Question is how long do i leave it on until it is the correct "volume"to pitch into 23l of around 1044wort is the 24hr mark ok??
> cheers



Turn stirplate off at krausen & put the starter in the fridge until you're ready to pitch. You will now be pitching with an "active" yeast.

TP


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## humulus (6/1/12)

TidalPete said:


> Turn stirplate off at krausen & put the starter in the fridge until you're ready to pitch.
> 
> TP


Cheers T.P appreciate the advice :icon_chickcheers:


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## mika (6/1/12)

TidalPete said:


> Turn stirplate off at krausen & put the starter in the fridge until you're ready to pitch. You will now be pitching with an "active" yeast.
> 
> TP



I tend to disagree. If the yeast is in the fridge (presuming you mean beer fridge @~4C) for any reasonable period of time the yeast is going to go dormant and your starter will no longer be 'active'. You'll have built a decent pitching volume, but the yeast will most likely be dormant and will need to 'wake up' before going to work on your wort.


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## peaky (6/1/12)

I always chill the starter and decant the beer off then rewarm the yeast up to pitching temps. Not sure it's a good idea to pitch chilled yeast into wort that is sitting at fermenting temps. The yeast certainly would not be 'active'.


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## DUANNE (6/1/12)

my personal preferance is to let the wort ferment out fully on the stirplate usually in 24-36 hours and chill and decant the starter. several reasons for this including not pitching an already oxidised wort into the main beer and not wanting to dilute my carefully prepared wort with a starter that does not match the beer im trying to create. yeast do not create alc in an aerobic situation so all you will end up doing is diluting your beer with estery water. the flavour profile will not be what the main beer is so whats the point? i cant understand the idea that the yeast has to be pitched in a completely active state unless you are lax in sanitisation and have to get the yeast to try and beat any bugs to ferment. i have chilled decanted and had just yeast pitched and still had an active ferment going within 6 hours. why risk a beer you have spent time, effort and money on by pouring a couple of litres of crap into it. if you want to pitch active you might as well do a simple starter with aeration at the start and accept that you are missing out on all the yeast growth advantages of a stirplate.my 2c ymmv and so on


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## TidalPete (6/1/12)

mika said:


> I tend to disagree. If the yeast is in the fridge (presuming you mean beer fridge @~4C) for any reasonable period of time the yeast is going to go dormant and your starter will no longer be 'active'. You'll have built a decent pitching volume, but the yeast will most likely be dormant and will need to 'wake up' before going to work on your wort.



Exactly! You've got it in one mika.
On brewday after chilling (or next day if doing no chill) & before draining to fermenter, the brewer releases 1 or two litres from kettle or container into a sterilised jug which is added to the (chilled) starter after the starter is emptied of surplus wort & brought back to room temp. These 1 or 2 litres (I prefer 1) are actually part of your final fermentation volume. From experience, it only takes a short time for the "active" starter to reach krausen & is then pitched to fermenter when both temps are approx the same & yes I do aerate the wort after pitching.
Pitched for years after letting the starter ferment out on the stirplate without problems (mostly anyway  ) but since being put onto the active starter thingo by a champion brewer from Gumpy :beer: have realised much faster starts to fermentation.
Each to his own I guess?  

TP


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## Crusty (8/1/12)

humulus said:


> Cheers crusty! running in and out of my shed like an expectant Dad! looking at it!
> Ill be ready to chill and pitch tomorrow arvo!



I always do my starter a couple of days before brewday. If I am brewing on Saturday afternoon, I make my starter on Thursday night, let it spin for a full 24hrs, it's complete on Friday night. I then place it in the fridge & on Saturday morning, take it from the fridge & let it warm up to room temperature. When ready to pitch, I decant as much of the wort as possible & leave just enough to swirl the yeast into suspension & pitch.


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## TheWiggman (16/6/14)

I figure this is as good a place as any.

I've done 2 yeast starters on the stir plate now - 1 straight into the brew (but split a stubbie off it) and another which I prepared for a friend. I've got doubts about the time and/or what's happening. Here's what I did -

Recovered some yeast from a Coopers brew (using sediment yeast) I did a few months back. In a stubbie in the fridge.
Made 500ml wort (LDM) to about 1.030 to give it a kick start.
Ran on stir plate for 24h
Added 1l containing 130g LDM to starter. It kicked off to a high krausen in about 5 mins (no kidding)
Ran on stir plate for 30h
No krausen. Turned off. Immediately tipped 375ml into a stubbie - put in fridge for a later starter
Left flask to settle overnight
Clear separation in the flask next morning. Decanted clear liquid from top, and tipped remaining 750ml of yeast into a swingtop bottle.
I left the bottle at room temp overnight then came back the next day. I decided to see if any gas would purge and blow me down, purge it did. If I opened it enough I can guarantee it would have been a gusher.
Is this a Coopers yeast thing or what? Considering it's carbonating the bottle that implies to me that the yeast is still active. This is a practice I'm considering continuing in the future and I don't want to pack the fridge full of bottle bombs.


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## mje1980 (16/6/14)

I'd use 600ml coke bottles. Easy to purge the gas if it looks swollen.


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## mckenry (27/3/15)

I've been doing some pondering about yeast starters lately. Especially since my last two have tasted tart. I threw the first one, assuming it was bad. Second one I figured I was really clean and careful, so it must be ok. Pitched it and the ferment is going well and sample tastes as it should at 1.035 Theyve never tasted tart to me before. I cant explain it as my process hasnt changed. One was Cali V the other Oktoberfest/Marzen
Now, I've done at least 100 yeast starters in my life. Ive probably done 70 of those on a stir plate.
Here are my thoughts, which dont seem to have been covered anywhere on here I can find.
I have always run my stir plate the entire time I've been growing the yeast. Sometimes 7 days. Even when I have to do 3 steps, I've always left it running until its done and needs to flocc so I can ditch the over oxygenated liquid.
Ive been wondering if this is necessary, or possibly even bad. 

So, should it run the entire time or just til fermentation starts? Im thinking once it gets going its away and no longer needs feeding of o2.
What about stepping up? (I decant then pitch the slurry into the next step) Do we need to restart the oxygenation process? Then for how long?
I have also sent this question to the makers of yeastcalc as they dont seem to have info on it either.


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## Yob (27/3/15)

When stepping up, as I usually do, I do so when I notice activity, colour change, respiration, a small bit of foam, ideally you don't want to let them start to ferment. If I start on a 500ml flask, my 2000ml starter I do as 200g but into 1.5l if that makes sense? That way I can tip the full 500ml in and keep going. Once the 2000ml is done, then I'll let floc, decant, pitch. 

Right or wrong, dunno, just how I seem to get best results


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## mckenry (27/3/15)

Yob said:


> When stepping up, as I usually do, I do so when I notice activity, colour change, respiration, a small bit of foam, ideally you don't want to let them start to ferment. If I start on a 500ml flask, my 2000ml starter I do as 200g but into 1.5l if that makes sense? That way I can tip the full 500ml in and keep going. Once the 2000ml is done, then I'll let floc, decant, pitch.
> 
> Right or wrong, dunno, just how I seem to get best results


Thanks Yob. I'm more interested in the effects of O2, rather than when to step up. I step up when the krausen collapses. I dont really have much choice as I'm not home every night of the week, so its a best guess for me, which is why I'm interested in when to stop with the stirring.


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## danestead (27/3/15)

It's written in my yeast notes at home which I wrote up based on reading books and listening to podcasts but ideally you want to turn the stirrer off once fermentation has finished, and then leave the yeast in the flask for 9hrs without the stir bar on. I believe the reason this is done is because once the fermentation has finished, if you keep it stirring and adding oxygen, it reduces the health of the yeast or the yeast don't create their glycogen reserves etc. It's along those lines but I'm not home atm.

As for turning the stir bar off as soon as fermentation has started, I don't know.


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## marksy (27/3/15)

I just did a 3L starter for my 38L batch and harvesting.

I've always wondered if there is a better way, or if I am doing it wrong, I haven't had any trouble yet. 

My stir plate isn't very crazy, and the vessel I use is a small 5L glass fermenter, so I can't go too fast or the bar always shoots off. I find that after a few days the yeasts starts to clump together and fall down around the sides, then I usually give it a good shake and let it sit for 8hrs to hang out before chilling, then pitch the next day, usually and save a vial of it for next time. 


marksy


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## Adr_0 (27/3/15)

I've found that yeast will generally settle out once it's done, rather than with the help of refrigeration - which to me creates more chance of stress when you pitch it. 

As others have said, after 24hrs things should be well and truly done, assuming you have a gravity of 1030-1040. Then just turn it off and drag the stir bar up the side of the flask with a magnet. 

Generally I will start the starter on Friday evening with a plan to pitch Sunday night. This gives time to settle out, pour off liquid, add a litre of freshly brewed wort, let that fire up then chuck it in.

I think Chris White or Jamil said to keep the yeast within 10°C of whatever you're putting it into. If I compare my beers where it had taken off and had a great ferment, this requirement (with good growth in the starter) had been met. Those that took a little while to get going generally had a temperature shock. This includes 'slow' and 'fast' yeasts, eg I have had 1214 and 1275 start building pressure in 4-6 hrs. So I'm a firm believer in the 10°C thing.


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## nosco (10/4/15)

Im only on my 7th starter atm :unsure: but Im with Adro_0. The yeast will settle out without refrigeration on its own. Depending on the yeast I guess. Might not work with a kolsch yeast.

I have been treating my starters like a beer. I leave the stir plate on over night then turn it off in the morning. Let it ferment out then when its clears and the yeast settles I decant and pitch (only doing no chill so far). I think Palmer says you should let starters ferment out to build up the yeasts glycogen reserves. So thats what Ive been thinking around. It has worked well so far. But....

I have split my first smack pack this time around. A lager yeast (Wyeast 2002 for the hell of it) so I was planing to step up 3 times. I used 10:1 DME mix to start with 1/2 a smack pack. Its been going since Monday night! I tried to decant last night but the yeast was still too unsettled. I was able to decant tonight and top up with 2lt of pre prepared wort but there was still plenty of bubble activity goin on. Im getting a little impatient but ill just have to wait it out. If I was using a chiller I would be screwed :blink:


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## Camo6 (10/4/15)

Once fermentation is complete I'm happy to turn off the stir plate as it's no longer needed. However if I do let it run the whole time I always refrigerate and decant and then warm up or start a small starter when ready to pitch.
If I pitch an active starter I'm not too concerned about oxidisation as the majority of the wort is still fermenting and in need of the o2.
Fwiw I've tasted a few tart starters and they never seem to have much result on the finished beer to my untrained palate.


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## Yob (10/4/15)

Good to know, I usually ditch if i get tart.. I always thought there was something amiss with it


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## Camo6 (10/4/15)

To clarify: tart not sour!


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## Yob (10/4/15)

aye, nothing wrong with a bit of tart h34r:


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## nosco (11/4/15)

Just a few of my questions answered here

http://www.mrmalty.com/starter_faq.php


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