Yeast Starters

[GuingesRock]

My stir plate arrived just now. Do people chill their starters and decant off the liquid, or do they keep at room temp and pitch the whole thing?

[adams81]

Chill and decant here

[mcgster]

I chill it for about an hour or two, then decant most of the "beer" off the top and leave maybe 300ml

[LeafMan66_67]

My stir plate arrived just now. Do people chill their starters and decant off the liquid, or do they keep at room temp and pitch the whole thing?

Depends on the starter size - I wouldn't want to pour in 2L of crappy, oxygenated wort into my 20L of fresh wort.

[Broob]

Do most people use a stir plate? Anyone use the ol' intermittent shaking method? According to Mr Malty the starter size for the latter is much higher.

[RubberToe]

My stir plate arrived just now. Do people chill their starters and decant off the liquid, or do they keep at room temp and pitch the whole thing?

I try to cold crash for at least 24 hours if I can, then decant.

Some people build their starter wort into their recipe and pitch the whole thing. There's also advantages to pitching a starter at high krausen.

[GuingesRock]

There's also advantages to pitching a starter at high krausen.

Any chance of a compromise here?

When you pitch yeast into your wort, you oxygenate the wort, the yeast takes down the O2 to about Zero over about 1 day (?) and presumably not much oxygenation of the wort occurs in that time period, otherwise people wouldn't do it.

Suppose you pitch the starter when it is at high krausen, lets say at 36 hrs (?) that's not much longer that wort is exposed to O2 than the full batch. How much more oxidation can be occurring in the extra 12 - 24 hrs? Also pitching at high krausen might bring down the O2 in the fermentor more quickly than pitching chilled yeast would?

What's wrong with this argument? correct my time periods if incorrect also please.

[RubberToe]

I don't think there's risk of oxidizing your wort by pitching an oxidized starter. Starters have all sorts of off flavours and undesirable characteristics you don't find in finished beer and the yeast clean things up. I'm hesitant but I understand it's probably not an issue.

I personally just don't want to pitch 2.5 litres of DME wort into my all grain brew. That's the main reason I decant.

I'm willing to bet most commercial brewers pitch the whole starter too.

[Woody]

G Rock I sometimes leave making a starter until the day before and pitch the whole thing into my wort at high krausen 18-24 hours later. If I actually plan far enough ahead I prefer to leave it on the stir plate for 48 hours and throw it in the fridge. I then decant and leave the yeast at room temperature as to not shock it for a few hours while I'm making the beer and dump it into oxygenated wort. I dubbed your fermenting in the pot method the G-Rock shuffle and do it even with liquid yeast from time to time. I sanitize a fermentation pale and let the wort fall into it and dump it back into really get oxygen into it. I ferment with hops etc in the pale so mixing it up doesn't concern me. So to make a long story longer decanting or pitching at high krauzen is a matter of preference and when you may have started your starter. If I plan a day in advance and am using a liquid yeast I'm pitching at high krauzen and if I plan well in advance I throw it in the fridge covered with tin foil and decant and leave at room temp before pitching.

[amartin]

My stir plate arrived just now. Do people chill their starters and decant off the liquid, or do they keep at room temp and pitch the whole thing?

I try to cold crash for at least 24 hours if I can, then decant.

Some people build their starter wort into their recipe and pitch the whole thing. There's also advantages to pitching a starter at high krausen.

Like me, for instance. Depending on how long the yeast has been in the fridge, this could mean starting it anywhere from 36 hours out to the morning of brew day. I like knowing that the yeast is active when I pitch it. I also like top cropping and reusing yeast as long as I can. If I was to decant, I'd be favouring the yeast that drops out quicker, rather than the top cropping yeast that I want to collect later on.

I'm not sure I'm understanding the oxygenation issue. The yeast uses up the oxygen in the starter, and then it gets added to the full wort, which should also have a lot of oxygen in it at pitching time. What is the problem here?

A potential downside is that you're also pitching diacetyl, fusels, etc., that haven't been cleaned up, but really, this is only 10% or so of your total, and if you give it long enough in the fermenter, it should clean up.

[RubberToe]

I'm not sure I'm understanding the oxygenation issue. The yeast uses up the oxygen in the starter, and then it gets added to the full wort, which should also have a lot of oxygen in it at pitching time. What is the problem here?

If one were using a stir plate they'd get constant aeration even after the yeast are don their job. That's the only way I can think of. But you're right, it should get used up again. I don't know if the starter wort would be unreversibly oxidized.

[RubberToe]

Someone should check the yeast book for this.

[amartin]

Yeah, I forgot about stir plates. Can you turn them down, just enough to keep the yeast moving?

[Woody]

There are different speeds on my stir plate and it goes down pretty low so I'll go with yes. On another note a starter is oxidized as hell when you use a stir plate but that should not be an issue if pitched into a batch of beer. The yeast will clean it up as the idea is to just increase the cell count.

[Ladd]

If you are pitching your whole starter, I've heard/read Jamil recommending to keep the starter volume at or below 5% of the total volume or ~1L starter per 5 gallon batch. I've done both crashing/decanting and pitching the whole thing and haven't noticed any off flavors with either. I have noticed faster starts with pitching the whole active starter though.

What I've been doing lately is a combination of the two. I'm making my starters a few days in advance, crashing them down a night or two before brew day in the fridge and the morning of the brew I decant the supernatant and add back 250-500ml of new wort (I save and can some from the previous batch just for this purpose) to re-suspend the yeast. I let this mix warm up to room temp on my counter while I am getting ready and while I am brewing. This wakes the yeast back up and gets them good and active by the time I am ready to pitch (4-6 hours later) and it keeps the total volume of the starter you are pitching low in case you are paranoid about off flavors (as most of us always are...).

I don't use a stir plate either, just the old grab and shake every time I walk by

[GuingesRock]

That's all really interesting. Thanks

I'm tempted to pitch the whole starter when it's at high Krausen and get that wort fermenting ASAP and kill off any bacteria with alcohol, before they start making off-flavours. Also, it sounds quicker and easier. I'll put extra effort into something, if there's a clearly established good reason to do so.

Been looking up previous yeast discussions here, and came across these threads:

http://www.brewnosers.org/forums/viewto ... f=3&t=1689" onclick="window.open(this.href);return false;
http://www.brewnosers.org/forums/viewto ... ?f=3&t=732" onclick="window.open(this.href);return false;
http://www.brewnosers.org/forums/viewto ... f=3&t=1694" onclick="window.open(this.href);return false;
http://www.brewnosers.org/forums/viewto ... f=3&t=4372" onclick="window.open(this.href);return false;
http://www.brewnosers.org/forums/viewto ... f=3&t=5530" onclick="window.open(this.href);return false;
http://www.brewnosers.org/forums/viewto ... f=3&t=5814" onclick="window.open(this.href);return false;
http://www.brewnosers.org/forums/viewto ... f=3&t=5928" onclick="window.open(this.href);return false;
http://www.brewnosers.org/forums/viewto ... f=3&t=6178" onclick="window.open(this.href);return false;
http://www.brewnosers.org/forums/viewto ... f=3&t=5831" onclick="window.open(this.href);return false;
http://www.brewnosers.org/forums/viewto ... =13&t=3877" onclick="window.open(this.href);return false;

[GuingesRock]

If you open a can of beer and leave it half empty in the fridge for a week, it gets pretty rank and nasty, and I wouldn’t like to pour ½ can of spoiled beer into a full batch of freshly made wort.

If you store yeast in a mason jar under its own "beer" for a couple of weeks, doesn’t the same thing happen? In that instance, you’re probably going to mostly decant off the nasty stuff.

That whole scenario wouldn’t happen when you pitch a whole starter at high Krausen.

Could this be where the idea that you have to decant off starter "beer" because it has a foul taste, comes from?

I will put some beer in a flask on the stir plate for 24 hours and see what it tastes like. I'll have to cover the flask with foil so the hop oils don't get skunked by the daylight.

[Woody]

I wonder if that can of beer would be rank and nasty if covered like a starter? I'm guessing not. I've pitched a starter after a week in the fridge with no issues. If you want to pitch at high krausen and toss it in I think it's a great idea and doubt you will have any issues. I always smell my starters before tossing them in. My guess is that when you taste your starter after 24 hours it will taste oxidized. You don't need to cover the whole flask with tin foil just the top to keep anything from getting in. Unless your stir plate is in the direct sunlight which would change the game. I do this in the basement so it hasn't been an issue.

[AllanMar]

If you open a can of beer and leave it half empty in the fridge for a week, it gets pretty rank and nasty, and I wouldn’t like to pour ½ can of spoiled beer into a full batch of freshly made wort.

If you store yeast in a mason jar under its own "beer" for a couple of weeks, doesn’t the same thing happen? In that instance, you’re probably going to mostly decant off the nasty stuff.

That whole scenario wouldn’t happen when you pitch a whole starter at high Krausen.

Could this be where the idea that you have to decant off starter "beer" because it has a foul taste, comes from?

I will put some beer in a flask on the stir plate for 24 hours and see what it tastes like. I'll have to cover the flask with foil so the hop oils don't get skunked by the daylight.

Oxygenated beer does not taste good. A stir-plate starter will be oxygenated (that's the point right?). It doesn't taste good. Weither you should decant would be how much of a difference thats going to make (back to the dillution point), if its a really light beer (light ale or lager) I usually decant, otherwise if it's not a super-light beer and I dont have the time I dump the whole starter in (if it were a really big starter i'd also decant).

I guess, decant if you have the time, if not don't worry too much about it odds are you'll be fine.

[Juniper Hill]

I've been making my starters (2 L usually) 24-48 hrs before brewday using the stir plate method for aeration. I've pitched the entire starter into the batch (5 gallon). Takes off within 12-24 hrs, often like a rocket. I haven't noticed any off flavours.

[GuingesRock]

I just put a flask of beer from one of my kegs on the stir plate. I'll whirr it for 24 hours and then taste. I did put a cloth over it to keep the light out, as unlike a the usual non hopped starter, I think I could get skunking otherwise, which might confuse the issue.

[GuingesRock]

I just put a flask of beer from one of my kegs on the stir plate. I'll whirr it for 24 hours and then taste. I did put a cloth over it to keep the light out, as unlike a the usual non hopped starter, I think I could get skunking otherwise, which might confuse the issue.

The beer on the right with the stir bar in it (gonna have to learn not to lose the stir bar like that) was put on the stir plate for a day and then chilled in the fridge for an hour.

The beer on the left was poured from the same keg and put in the fridge for an hour.

The stir plate beer is darker in colour. It tastes like sherry and cardboard and your mouth takes a long time to recover from the unpleasant experience.

I think I am going to chill and decant before pitching. I’m not a strong believer in the dilution theory. If a seagull flew over and shat in my soup, I wouldn’t stir it in and carry on eating, no matter how many thousand times it was diluted. Plus my starters will be 3L in size.

I think that a non-stirred starter, or one that’s just been shaken a bit initially, might be fine to pitch the whole thing at high krausen. I haven’t tested that, but it would be easy enough to put some beer in a flask for a day and see what it tastes like.

[AllanMar]

Dillution isn't exactly a theory you can just ignore, but ignoring that point. Oxygenated yeast starter isn't exactly seagull shit either.

You like experiments, try it. 3L in a 12gal batch of anything but a really light beer will be really tough to notice.

I don't know what the point of this experiment was, oxygenated beer tastes bad.... I thought that was a well known fact.

A non-stirred starter, is basically a batch of really plain beer is it not?

[amartin]

Dillution isn't exactly a theory you can just ignore, but ignoring that point. Oxygenated yeast starter isn't exactly seagull shit either.

You like experiments, try it. 3L in a 12gal batch of anything but a really light beer will be really tough to notice.

I don't know what the point of this experiment was, oxygenated beer tastes bad.... I thought that was a well known fact.

A non-stirred starter, is basically a batch of really plain beer is it not?

More or less. I used to decant off, and then drink it, because why not?

[GuingesRock]

I don't know what the point of this experiment was, oxygenated beer tastes bad.... I thought that was a well known fact.

Do you want to know what the "point" was or are you just wanting to put my efforts down.

The "point" was to find out how much the beer would become oxidised on the stir plate in 24 hours. I was hoping it wouldn't be enough to be of concern, and that I would be happy to pitch 3L at high krausen. It was a check before I did that, and I was disappointed to find that it was very oxidized. It was an experiment to help me decide whether to pitch a stir plate starter at high krausen, or chill and decant.

If it seems a stupid thing, and is of no use to anyone, let me know and I'll delete the post.