Starter: how long to keep on stir plate?

(Sorry if this is common knowledge, but I've tried many searches and can't seem to find an answer to this in any of the threads about starters and stir plates.)

I made my first starter last night and have had the flask on a stir plate for about 12 hours, with a nice steady vortex. There's 750 ml in the flask (it's a 1 liter flask), 75g of DME and 1 tube of White Labs WLP001 California yeast (very fresh). The beer it'll be going into will be a Ruination IPA clone, with target OG of 1.076.

So, my basic question is how long should I keep it on the stir plate? Is there a general rule of thumb for this? And, what's the best way to determine if fermentation in the starter has begun? Do you just turn off the stir plate and wait until fermentation foam is seen?

I usually make my starters 15-18 hours before I brew so the yeasts are nice and hungry when I pitch them. I keep it on the stirplate until right before I pitch so all the yeast stay in suspension and nothing gets stuck to the bottom of the flask. This is just my technique - I'm sure there are a lot of other ways of doing it.

I generally run the stir plate 24 - 36 hours. I don't worry about a vortex, just run it fast enough to keep the yeast suspended.

Quick update: just to see what might happen, I turned off the stir plate at pitch + 19 hours and capped the flask with an airlock. Started seeing fermentation bubbles within 15 minutes.

www.mrmalty.com

Go to the calculator. Bookmark and reference as one of the best free homebrew resources on the web.

I usually run my stirplate for 48 hrs with foil on top and then put it in the fridge for a day. I will pull it out in the morning and let it slowly raise to room temp as I am brewing my wort.
After being a panicky noob when I didn't see any krausen on my second attempt, I learned from everyone that krausen will not appear on all yeasts.

Now I pretty much don't worry about it and pitch it and see what happens as it sits for a day or two.

I have a delay in my brew day after beginning my yeast starter. I usually do about 36 hours on the stir plate. Now it will be about 60 hours. Is this a problem?

Not a problem, but don't leave it on the plate all 60 hours. After your typical 24-36, put it in the fridge till you're ready, and then let it warm up while you brew.
Just like DutchK9 does.

I wouldn't even put it in the fridge. People pitch on yeast cakes all the time that have been sitting in the fermentors for weeks.

I try to do stir plate for 2 days prior to brew day.

When I see bigger chunks of yeast in the plate, I know the colony has grown (they werent there before) and they are starting to flocculate.

Then, I take off the stir plate and fridge for about 8-10 hours before pitch time.

This allows me to crash them, pour off some (NOT ALL) of the starter wort and then swirl and pitch the yeast with less wort.

Concur with Hiphop on this. I brew every Saturday and start my starter around noon on Thursday, leave it on the stirrer until i pitch and have had no isues pitching around noon on Sat. Usually get activiting with in 2 hours of pitching.

hiphopopotamus said:

I wouldn't even put it in the fridge. People pitch on yeast cakes all the time that have been sitting in the fermentors for weeks.

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depends on what you are trying to achieve .. I do one to two step ups because I do 10-20 gallons at a time. I do 2 liters then crash it to get rid of the spent wort now actually beer that has been oxygenated. Pour it off and let it warm and pitch another 1-2 liters of fresh wort let her go again then crash again.

pitching on a cake is totally different than a starter .

Many thanks for your suggestions. Very helpful and puts my mind at ease. Cheers!

i know this isn't a new thread but after having the yeast on the stir plate why would you need to cold crash them then warm em up again? wouldn't you want to pitch right into your wort if you have it ready rather than having to wake the yeast you just spent 2 days making a starter of?

IMO Cold crashing helps the yeast drop, thus making it easier to decant some of the liquid. Spun starters are pretty blah tasting and adding 1.5L of that to my beer im obsessing over doesnt seem ideal.

Smaller starters aren't going to "show" a whole lot of activity. I usually eyeball it and if I'm not sure, a full two days.
I crash it in the fridge until brew day, decant most the beer off, swirl, and pitch. Yeast don't care if they're cold. If your wort is aerated well they'll take off in a few hours.
Also, don't leave at ambient temp any longer than you need to in order to populate. Your viability will drop quickly at room temp.

dalime... one quick question.

Snip taken from the White Labs site on starters:

"...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 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 (room) temperature, rouse the starter yeast into suspension and pitch the entire quantity into your fermenter."

White Labs

Why do you say your viability will drop quickly at room temp? What's your average ale fermentation temp? A little cooler than room temp, no?

I usually do 24 hours for ales and 48 for lagers. Then crash cool for 2 days before brew day. On brew day I decant off most of the liquid and then place it back on my stir plate at room temperature (or 50 degrees for algers) so that everything is stirred up real nice once it is pitching time a couple hours later.

dalime said:

Smaller starters aren't going to "show" a whole lot of activity. I usually eyeball it and if I'm not sure, a full two days.
I crash it in the fridge until brew day, decant most the beer off, swirl, and pitch. Yeast don't care if they're cold. If your wort is aerated well they'll take off in a few hours.
Also, don't leave at ambient temp any longer than you need to in order to populate. Your viability will drop quickly at room temp.

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I was just reading a thread on cold pitching. Seems like the way to go.

macleod319 said:

dalime... one quick question.

Snip taken from the White Labs site on starters:

"...Once the yeast and your wort are at approximately the same (room) temperature, rouse the starter yeast into suspension and pitch the entire quantity into your fermenter."

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When I began making starters I took my cues from Wyeast (I now use WL) but they never suggested letting the yeast get up to room temp and it's never been a problem for me. The way I see it, once you dump them in the wort, they are going to get to beer temp real fast. Wort temperature, good aeration, and healthy cell counts will get you less lag time. I personally don't think the the pre-pitch yeast temp matters all that much.

Why do you say your viability will drop quickly at room temp? What's your average ale fermentation temp? A little cooler than room temp, no?

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I should have been more clear; if they don't have anything to eat, your viability will drop off quickly. So you want to make sure that once your starter is finished, you either pitch it or chill it.

Cool, thanks.

I feel that the best way to go about it is to make your starter and shake the wort up in the flask to aerate prior to placing on the stir plate so the yeast have plenty of oxygen to start with then the stir plate will continue to aerate and keep them in suspension. If you allow the yeast to go 48 hours in the starter that allows them to fully multiply, ferment and for the most part finish fermenting the beer in the starter so that they will begin to store all of their reserves to be strong and healthy for the job that they are about to do in your primary.
I am like some of the others that like to place their starter in the fridge to floc out the yeast to decant the nasty beer in the starter. I spend too much time trying to perfect the batch to toss in a bunch of nasty beer which in some cases could be quite a bit when working with higher gravity beers.
So my full time from the beginning of a starter to pitch time would be about 72 hours to give a full pitch of yeast filled with the reserves they need without the excess beer in the starter. All of my ferments have turned out beautiful since I started this process and never end up short on my final gravity.
Of course all the above is when I have the time and planned my brew day ahead of time. The key is always to get enough yeast in the primary and I used Mr. Malty's calc but now I use the Brewzor app for Android phones. Awesome app check it out.

If my my WL Vermont yeast strain was possibly frozen in the tube would it kill the yeast? My guess is no. If it didn't kill it, should I be seeing only a small ring of bubbles in my flask on the stir plate. BTW my first time using a stir plate.

I have a yeast starter on the stirplate right now; it's been there for almost a week. Still safe to use? (I have plenty of other yeast, including the slurry I started this from) Smell/taste it to make sure it's not sour, then use it? I know it's active, there's a little foam on top even with the vortex.

I used 600ml of water, 60 grams of DME, a pinch of yeast nutrient (all this boiled and cooled) with a teaspoon from the bottom of a jar of yeast I collected a few months ago (stored in the fridge in a mason jar)

z-bob said:

I have a yeast starter on the stirplate right now; it's been there for almost a week. Still safe to use? (I have plenty of other yeast, including the slurry I started this from) Smell/taste it to make sure it's not sour, then use it? I know it's active, there's a little foam on top even with the vortex.

I used 600ml of water, 60 grams of DME, a pinch of yeast nutrient (all this boiled and cooled) with a teaspoon from the bottom of a jar of yeast I collected a few months ago (stored in the fridge in a mason jar)

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Yeah, that yeast starter should be fine as long as it was covered with foil and everything was done sanitary.
I've had yeast starters spin for a week or longer to revive older yeast (> 1 year).

Always a good idea to smell or taste it, although sometimes an infection may not show for weeks.

Did you use a yeast calculator?
A teaspoon of thick slurry may be a bit skimpy depending on how old it is and how much trub is in that slurry. Mr. Malty has a good estimator on the "pitch from slurry" tab.

In general a 1 liter starter is a bit skimpy for a 5 gallon batch unless it's low gravity (<1.045) or a much smaller batch. 2 liters is more common.
0.6 liter is really small. Hence the yeast calculator. You can always ramp this up to a larger amount.

Are you going to pitch as is or cold crash and decant?

Not covered with foil, but I stuffed some gauze in the top of the flask (I wanted to make sure air could get in/out but not fruit flies, dust, etc) I was gonna dump the whole thing in except hopefully the stir bar I brewed the beer today, and it's in the fermenter bucket now with a couple of 1L ice bottles to chill the rest of the way. (I have an immersion chiller but it sucks and usually only gets me down to about 85°) It's a 4 gallon batch, OG is 1.06-ish. The yeast is T-58, which likes it warm.

There's no reason I can't use the small starter AND the refrigerated slurry. Usually I just use a cup of slurry, but I wanted to make sure this was still good. And I wanted to practice using the stirplate.

z-bob said:

Not covered with foil, but I stuffed some gauze in the top of the flask (I wanted to make sure air could get in/out but not fruit flies, dust, etc) I was gonna dump the whole thing in except hopefully the stir bar I brewed the beer today, and it's in the fermenter bucket now with a couple of 1L ice bottles to chill the rest of the way. (I have an immersion chiller but it sucks and usually only gets me down to about 85°) It's a 4 gallon batch, OG is 1.06-ish. The yeast is T-58, which likes it warm.

There's no reason I can't use the small starter AND the refrigerated slurry. Usually I just use a cup of slurry, but I wanted to make sure this was still good. And I wanted to practice using the stirplate.

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A cup of slurry may be overpitching, but your 600 ml starter is definitely a bit low in cell count for 5 gallons of 1.060 wort according to the yeast calculators. My estimate is you have around 100-150 billion vital cells in that flask, while you really need 200 billion according to Homebrew Dad's Yeast Calculator. Now many recipes instructions are fine with pitching a single White Labs vial/pack or Wyeast pack into 5 gallons of 1.060 wort and they turn out great. Those packs contain around 100-125 billion cells at packaging, but are usually not that fresh, so cell count is definitely lower than that.

Sure you can add a little extra of that thick slurry to the fermentor, in addition to your 600 ml starter. Say another heaped tablespoon or 2? Depending on how much trub is mixed in with the harvested yeast, the estimate is 1-2 billion cells per ml of thick slurry (per Mr. Malty).

I took the starter off the stirplate yesterday afternoon and let it settle (not in the fridge). Last night I took a little of the liquid on top out with a pipette and tasted it; it was fine. I poured the whole thing in the bucket of wort. (didn't drop in the stir bar) I figured I could add a little more yeast slurry today.

This morning there's several inches of krausen on top. So think I'm going to leave it alone

What should I do next time? Use my big flask and do 1.5L? Or start with the 1L flask like I did this time, but step it up? Refrigerate the starter after 2 or 3 days on the stirplate, until I'm ready to use it? I don't want to put that much stale-starter-beer in my wort.

z-bob said:

I took the starter off the stirplate yesterday afternoon and let it settle (not in the fridge). Last night I took a little of the liquid on top out with a pipette and tasted it; it was fine. I poured the whole thing in the bucket of wort. (didn't drop in the stir bar) I figured I could add a little more yeast slurry today.

This morning there's several inches of krausen on top. So think I'm going to leave it alone

What should I do next time? Use my big flask and do 1.5L? Or start with the 1L flask like I did this time, but step it up? Refrigerate the starter after 2 or 3 days on the stirplate, until I'm ready to use it? I don't want to put that much stale-starter-beer in my wort.

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If you've got krausen already it's working. I don't think you'll need to pitch any more.

Pitching a (fairly) active starter, like you did, is actually better than pitching a cold crashed slurry, as the yeast is more vital at that moment. She goes dormant in the cold, and it takes time for her to "wake up" and get her metabolism going. So cell count is not everything, vitality (amount of active daughter cells) is even more important. Now since your starter has been going for a week, vitality goes up until the cell density has grown to the max, then vitality starts to drop off slowly as she goes go dormant (no food left). At least that's how I understand the process.

So proper timing of the whole starter process can help in providing you with healthy (vital) pitches.* Now there is something to be said about dumping 1.5-2 liter of oxidized starter beer into a 5 gallon batch of sublime fresh wort, but reports have been generally positive: no trace of that old starter is be found in the final beer. Of course there is a limit of how much of that you can add before you do start tasting it.

*Look up "Shaken not Stirred" starters, they rely on smaller but extremely vital pitches. Again, timing is essential here. A gallon glass jug would work great in a pinch as a propagation vessel for using that method in most 5 gallon batches. You'd only use 1-1.5 liter of starter wort. A slightly larger vessel (5-6 quarts) would be even better, but ever so hard to find for an affordable price.

If you need more time flexibility, yeah, make a 1.5-2.0 liter starter in a 2l flask and cold crash, decant and pitch slurry. If you overbuild that starter you can save some out left for a starter for your another batch, etc. (aka yeast ranching).

IslandLizard said:

Look up "Shaken not Stirred" starters, they rely on smaller but extremely vital pitches. Again, timing is essential here. A gallon glass jug would work great in a pinch as a propagation vessel for using that method in most 5 gallon batches. You'd only use 1-1.5 liter of starter wort. A slightly larger vessel (5-6 quarts) would be even better, but ever so hard to find for an affordable price.

If you need more time flexibility, yeah, make a 1.5-2.0 liter starter in a 2l flask and cold crash, decant and pitch slurry. If you overbuild that starter you can save some out left for a starter for your another batch, etc. (aka yeast ranching).

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On the AHA forum? That's an interesting topic. It never occurred to me that constant stirring would sheer-stress the yeast. (I'm still skeptical, but I haven't seen the data yet. It's an interesting hypothesis.)

I brew 4 gallon batches not 5 or 5.5, so that scales everything down just a little. I have some 4L glass jugs, but wouldn't a 3L plastic pop bottle be better since I could squeeze out the CO2 and replace it with air before shaking it? Now I gotta try to remember where I've seen 3L pop bottles instead of 2L...

I have a smack-pack of Wyeast 1762 (Belgian Abbey 2, rumored to be Rochefort) in my fridge that's been in there just over a year. This might be a good way to revive and use it instead of throwing it out.

z-bob said:

On the AHA forum? That's an interesting topic. It never occurred to me that constant stirring would sheer-stress the yeast. (I'm still skeptical, but I haven't seen the data yet. It's an interesting hypothesis.)

I brew 4 gallon batches not 5 or 5.5, so that scales everything down just a little. I have some 4L glass jugs, but wouldn't a 3L plastic pop bottle be better since I could squeeze out the CO2 and replace it with air before shaking it? Now I gotta try to remember where I've seen 3L pop bottles instead of 2L...

I have a smack-pack of Wyeast 1762 (Belgian Abbey 2, rumored to be Rochefort) in my fridge that's been in there just over a year. This might be a good way to revive and use it instead of throwing it out.

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Yup, that's the post/article.
You could try it with a plastic 3l soda bottle, but it will be single use most likely unless you have the patience to clean them, which is very doable. I don't think driving off CO2 formation is a big issue, even if using a glass jug. There may not be a lot of CO2 formation anyway as the yeast is not fermenting yet, she's in lag phase, which is where she mostly propagates. You have access to O2?

That would be a good experiment. Just don't blame the method if it fails.

I've been using my stir plate successfully for quite a while now, I don't turn it up to vortex force so I'm not particularly worried about harming the yeast.

I've been making starters for a couple of years now and have had great success in doing so. It's not only economical but fun, too. I usually use Homebrew Dad's yeast calculator which is great if you save off a little of the starter for another brew; it's usually in the ballpark with some of the other yeast starter calculators. My routine calls for at least a 24 hour fermentation on the stir plate. I use DME for the wort and I do not add any yeast nutrient in the starter. I don't always stick to the time frame, after the krausen falls you can definitely see a color change and the consistency shows some changes, like waves or layers swirling around. This I interpret as fermentation completed, I then cold crash it until clear or almost clear, at least another 24 hours. I may build up another step or decant the beer and pitch the slurry. I have read somewhere and heard from professional brewers that overpitching yeast is practically impossible for a homebrewer. With that in mind, my last batch was a 5 gallon Czech Pils to which I pitched a 4L starter, leaving just over 500ml of slurry. The beer completed primary fermentation (56*F) in four days. The resulting quaff was quite delicious. So, when planning a brew day I figure on at least a 2 step starter, that's 24 hours for the first fermentation, a 24 hour crash before starting the next bigger step and repeat for a total of 4 days, then brew on the fifth day. Begin the starter on Monday in order to brew on Saturday.

P.S. I always boil my starter DME in a metal pot, cool it, then pour it into an Erlenmeyer glass flask. The metal pot will cool faster than boiling in the pyrex flask, besides I have an induction cooktop so I must use a ferrous metal pot.

TennBrewer said:

P.S. I always boil my starter DME in a metal pot, cool it, then pour it into an Erlenmeyer glass flask. The metal pot will cool faster than boiling in the pyrex flask, besides I have an induction cooktop so I must use a ferrous metal pot.

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Yeah, I don't quite get the charm of boiling DME in a fragile glass container either. Most of those flasks are not suitable for direct heating on a stove anyway, plenty of posts and pictures to testify that.

The SS pot can be chilled much quicker in a sink or small tub filled with cold water and isn't fragile. Refresh the water once it gets hot. I often boil close to 5 liters, so I can fill 3 flasks (or 64 oz glass pickle jars) with 1.6 liter each.

Coincidentally, I also use an induction source, alas, just a single 3500W countertop plate.

I might can some quart and pint mason jars of starter next time I get out the pressure cooker. This was my first time to use a starter; nit was pretty easy even tho' I didn't really know what I was doing. And it allowed me use the yeast slurry from a very dark strong beer to make a light blonde.

z-bob said:

I might can some quart and pint mason jars of starter next time I get out the pressure cooker. This was my first time to use a starter; nit was pretty easy even tho' I didn't really know what I was doing. And it allowed me use the yeast slurry from a very dark strong beer to make a light blonde.

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I can chill 1.6 liter of DME wort down to starter pitching temps in under 15 minutes. Is it worth the bother of canning 6-8 jars of it?

If the beer the yeast was harvested from was very strong beer (say over 1.080), you'd be better off using a fresh starter from some yeast you ranched (saved) off a previous starter, or from a beer that hasn't been stressed as much. How did that light Blonde turn out?

IslandLizard said:

I can chill 1.6 liter of DME wort down to starter pitching temps in under 15 minutes. Is it worth the bother of canning 6-8 jars of it?

If the beer the yeast was harvested from was very strong beer (say over 1.080), you'd be better off using a fresh starter from some yeast you ranched (saved) off a previous starter, or from a beer that hasn't been stressed as much. How did that light Blonde turn out?

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Don't know yet, it's still in the ale pail. The previous beer was less than 1.080, but not a lot less (I really need to start keeping a brewing notebook) The krausen just fell so I need to rack this to a carboy for another week or so.

That's a good point about is it worth the trouble and worth a canning lid.

fwiw...the last few starters I've built I did not actually boil the DME at all. I boiled the water in a lidded pot, turned off the heat, mixed in the DME, put the lid on and let it sit for 5 minutes before chilling it down to pitching temperature then pouring it into a sanitized e-flask and adding the yeast.

I've based this approach on any of the pasteurization temperature vs time tables and the realization that the solution won't get any hotter than 212°F ASL unless a pressure cooker is involved, so why bother with prolonged boiling at all...

Cheers!

[edit] I run starters for 24 hours then crash, decant, and step or pitch...

I usually put it on the stir play for a few 2 or 3 days and continuously add for wort to it.
Then on brew day, I throw the active starter into the fermenter.
There is no lag and it gets going within a could hours.