Can't trust my yeast.

[slayer021175666]

Hello.
I was going to brew today but when I opened the lid on one of my yeast jars, a whole lot of CO2 came out and it foamed over a little bit. I squeezed the lid back on it and have been trying to get the CO2 out of it for about a day. I'm just wondering if it has went bad because of the co2. If I taste it, it tastes acidy but, I can't tell if that is actual acidy or too much star san that I used sanitizing the jar or if a high amount of CO2 makes it taste acidy. Can someone tell me what you think I should do? I'm open to any opinions or thoughts. It was top cropped yeast from my last batch of American wheat beer and it looks nice and clean. It was stored in RO water from the grocery store.
Thank you

 

[balrog]

vinegar tart taste could be infection, and if something got to any remaining sugars from the wort that came with the top cropping, it would do that, but it doesn't mean it did do that. Would've been good to know what the surface looked like before opening and the resultant outgassing stirred it all up.

I would vote for tossing, but that's because I operate on the simple principle that when my saved yeasts look, smell, taste, act "different", then I don't want to deal with whatever may have caused it.

 

[slayer021175666]

vinegar tart taste could be infection, and if something got to any remaining sugars from the wort that came with the top cropping, it would do that, but it doesn't mean it did do that. Would've been good to know what the surface looked like before opening and the resultant outgassing stirred it all up.

I would vote for tossing, but that's because I operate on the simple principle that when my saved yeasts look, smell, taste, act "different", then I don't want to deal with whatever may have caused it.

It's not vinegary. Maybe, acidy is the wrong way to describe it. It tastes something like a weakened peroxide. And, I don't really know how brewers yeast should taste. Should it taste like bread yeast? Like, really nice tasting like that or?
I did look at the yeast before I opened the jar. It looked really nice. I cold crashed it again overnight and it settled to the bottom and it looks really nice once again.

 

[balrog]

It is entirely possible that you just had more fermentation after cropping the yeast, if you cropped it while there was still something left to ferment. If you have another saved yeast you could compare. I have never tasted my saved yeasts, and only ever save overbuilt stir plate starters. About the question of CO2 making it go bad--no, they produce CO2 when they do their thing on sugar. Too much is bad for them, but they stop making CO2 before they reach a level that'll do them harm.

There are others here (@IslandLizard @doug293cz ) whom I would look for more knowledgeable answer than I might provide, but more info might be required to have a good answer.

 

[IslandLizard]

I've had similar foaming happening, often with Belgian yeasts, but others have too, at times.
I reckon it's still been fermenting a little in cold storage.

They typically show a few signs up front. One being a (slightly) bulging, or hard-to-the-touch (non-depressible) lid. This is due to internal pressure buildup, which you'll hear when releasing the lid/cap. That's your usual tell tale of what's coming next, as you just experienced!

Once the lid is released the pressure drops and little bubble spikes (fountains) start rising up from the bottom. It may develop into heavier foaming, even raising the whole yeast cake, making it ooze over the top. Just wipe it off and proceed as usually. As long as nothing has gone into your yeast, and you've been using good sanitation practices, as usual.

The smell/taste test:

If I taste it, it tastes acidy

Stored yeast slurries, reclaimed from fermentations or starters can have a slight acidity, yes. Fermented beer/starters have a pH of around 4.2.
The abundance of CO2 heightens that perception.

If it smells off, bad or sheer putrid (burnt rubber, or worse) your compost pile will gladly take it.

It's not vinegary.

That's a good sign!
You could make a small 24-hour starter with some. If it passes the smell test, taste a little. If anything is off you'll probably know by then.

 

[slayer021175666]

I've had similar foaming happening, often with Belgian yeasts, but others have too, at times.
I reckon it's still been fermenting a little in cold storage.

They typically show a few signs up front. One being a (slightly) bulging, or hard-to-the-touch (non-depressible) lid. This is due to internal pressure buildup, which you'll hear when releasing the lid/cap. That's your usual tell tale of what's coming next, as you just experienced!

Once the lid is released the pressure drops and little bubble spikes (fountains) start rising up from the bottom. It may develop into heavier foaming, even raising the whole yeast cake, making it ooze over the top. Just wipe it off and proceed as usually. As long as nothing has gone into your yeast, and you've been using good sanitation practices, as usual.

The smell/taste test:

Stored yeast slurries, reclaimed from fermentations or starters can have a slight acidity, yes. Fermented beer/starters have a pH of around 4.2.
The abundance of CO2 heightens that perception.

If it smells off, bad or sheer putrid (burnt rubber, or worse) your compost pile will gladly take it.


That's a good sign!
You could make a small 24-hour starter with some. If it passes the smell test, taste a little. If anything is off you'll probably know by then.

Thank you, Island lizard. I was hoping that you would chime in. Maybe I'm just freaking out a little because of past experiences. I think I am going to make a starter and smell it and taste it. If I just smell the yeast, it smells okay to me. It's when I taste it that it makes me worry. It certainly does not taste vinegary or sour. I've had a bunch of beers go sour on me and I know exactly what that crap tastes like! This is not that same kind of taste at all. I'm glad that you say the pH would be low and therefore acidy and that the CO2 would raise that perception. If the yeast is good, the starter might be a good idea anyway because, it's been in the fridge for about 1 month. It would help wake it up.

 

[slayer021175666]

I've had similar foaming happening, often with Belgian yeasts, but others have too, at times.
I reckon it's still been fermenting a little in cold storage.

They typically show a few signs up front. One being a (slightly) bulging, or hard-to-the-touch (non-depressible) lid. This is due to internal pressure buildup, which you'll hear when releasing the lid/cap. That's your usual tell tale of what's coming next, as you just experienced!

Once the lid is released the pressure drops and little bubble spikes (fountains) start rising up from the bottom. It may develop into heavier foaming, even raising the whole yeast cake, making it ooze over the top. Just wipe it off and proceed as usually. As long as nothing has gone into your yeast, and you've been using good sanitation practices, as usual.

The smell/taste test:

Stored yeast slurries, reclaimed from fermentations or starters can have a slight acidity, yes. Fermented beer/starters have a pH of around 4.2.
The abundance of CO2 heightens that perception.

If it smells off, bad or sheer putrid (burnt rubber, or worse) your compost pile will gladly take it.


That's a good sign!
You could make a small 24-hour starter with some. If it passes the smell test, taste a little. If anything is off you'll probably know by then.

I just noticed, you said to make a small starter with SOME of it. The amount I have is for a 10 gallon batch but, is there any reason I can't pour the whole thing into a quart or two starter just to, wake up ALL of the yeast?

 

[DBhomebrew]

Use a BIG container. I've had 500ml SNS starters climb out of a 1/2G jar.

 

[slayer021175666]

Use a BIG container. I've had 500ml SNS starters climb out of a 1/2G jar.

I have a 1 gallon jug I was going to use.

 

[IslandLizard]

I just noticed, you said to make a small starter with SOME of it.

Yes, I suggested only a small amount, to verify the batch of slurry is fine.
Any off-odors and flavors should become more prominent.

If the yeast is good, the starter might be a good idea anyway because, it's been in the fridge for about 1 month. It would help wake it up.

A harvested slurry that's been in the fridge for only 1 month should not need a starter, unless you're short on predicted cell amounts.
http://www.brewunited.com/yeast_calculator.php

The amount I have is for a 10 gallon batch but, is there any reason I can't pour the whole thing into a quart or two starter just to, wake up ALL of the yeast?

Nope, a vitality starter won't hurt a thing. It will likely shorten lag time, and speed up fermentation. More and healthier cells, better beer.

 

[slayer021175666]

Yes, I suggested only a small amount, to verify the batch of slurry is fine.
Any off-odors and flavors should become more prominent.


A harvested slurry that's been in the fridge for only 1 month should not need a starter, unless you're short on predicted cell amounts.
http://www.brewunited.com/yeast_calculator.php

Nope, a vitality starter won't hurt a thing. It will likely shorten lag time, and speed up fermentation. More and healthier cells, better beer.

Would you suggest one liter or 2 l starter for it? If it's 1 l, I could do in my 2 l flask and just boil it right on the stove but, for a 2 l, I would need to sanitize a lot more stuff and a funnel and all that because, I would need to put it in my 1 gallon jug.

 

[IslandLizard]

If I just smell the yeast, it smells okay to me. It's when I taste it that it makes me worry.

Saved out yeast can taste weird, there may also be trub mixed in.

It certainly does not taste vinegary or sour.
[...]
I've had a bunch of beers go sour on me and I know exactly what that crap tastes like! This is not that same kind of taste at all.

Those are important notions.

Have you found out why those beers went sour? That would be helpful, so you can avoid "making" more of those.*
The yeast you saved out, and you're going to use for this new batch, didn't come from one of those unintentionally soured beers, right?

* Have you thoroughly cleaned and sanitized everything those soured beers touched? Such as fermenters, lids, spigots, canes, hoses, you name it.
Have you taken apart and scrubbed the inside of your kettle's exit valve recently? Even at boiling temps for an hour, Pediococcus seems to be able to survive in there...

 

[IslandLizard]

Would you suggest one liter or 2 l starter for it? I 1 l, I could do in my 2 l flask and just boil it right on the stove but, for a 2 l, I would need to sanitize a lot more stuff and a funnel and all that because, I would need to put it in my 1 gallon jug.

What's the volume of your yeast slurry?
Was it harvested from a previous batch or directly from a starter?

I would never boil (starter) wort in a flask... it's only a matter of time before you end up with a huge mess, and no flask.
Use a stainless kitchen pot (with lid) instead. Chills faster in the sink (or plastic tub) filled with cold water too. Exchange the water once or twice, add ice on the last fill, if you need to.

Yeah, you're likely going to need a funnel.

 

[slayer021175666]

Saved out yeast can taste weird, there may also be trub mixed in.


Those are important notions.

Have you found out why those beers went sour? That would be helpful, so you can avoid "making" more of those.*
The yeast you saved out, and you're going to use for this new batch, didn't come from one of those unintentionally soured beers, right?

* Have you thoroughly cleaned and sanitized everything those soured beers touched? Such as fermenters, lids, spigots, canes, hoses, you name it.
Have you taken apart and scrubbed the inside of your kettle's exit valve recently? Even at boiling temps for an hour, Pediococcus seems to be able to survive in there...

I did find the source of the souring. It was inside of the Italian bucket spigots. Now that I've learned you can pop them apart, I take them apart and every time I see that there's stuff in there that you can't just spray out. You must pop them open to properly wash and sanitize them.

 

[slayer021175666]

What's the volume of your yeast slurry?
Was it harvested from a previous batch or directly from a starter?

I would never boil (starter) wort in a flask... it's only a matter of time before you end up with a huge mess, and no flask.
Use a stainless kitchen pot (with lid) instead. Chills faster in the sink (or plastic tub) filled with cold water too. Exchange the water once or twice, add ice on the last fill, if you need to.

Yeah, you're likely going to need a funnel.

It is top cropped from a batch of 1.056 American wheat Ale. I would say it's 3/4 or 1 inch of yeast cake on the bottom of a pint jar.

 

[slayer021175666]

What's the volume of your yeast slurry?
Was it harvested from a previous batch or directly from a starter?

I would never boil (starter) wort in a flask... it's only a matter of time before you end up with a huge mess, and no flask.
Use a stainless kitchen pot (with lid) instead. Chills faster in the sink (or plastic tub) filled with cold water too. Exchange the water once or twice, add ice on the last fill, if you need to.

Yeah, you're likely going to need a funnel.

It's a scientific borosilicate glass 2 l flask. I've been boiling in it for years and have never had a problem. It was sold to me as shockproof. But, you could be right. I'm not scared though. I've done it a lot.

 

[doug293cz]

There are others here (@IslandLizard @doug293cz ) whom I would look for more knowledgeable answer than I might provide, but more info might be required to have a good answer.

OT: I appreciate the vote of confidence, but I am not an expert on everything - and yeast is one area where there are many others on HBT who know much more than I do.

Brew on

 

[slayer021175666]

Island lizard? Sorry to be impatient but, I need to get this starter going. What size should I make it? Up above, I said how much I have in the jar. It seems to me like with 3/4 of an inch or an inch of yeast cake in the bottom of a pint jar, a 1 quart starter would probably do it but, I'd really like your input.

 

[DBhomebrew]

Go for it.

 

[slayer021175666]

Thanks guys!

 

[IslandLizard]

Island lizard? Sorry to be impatient but, I need to get this starter going. What size should I make it? Up above, I said how much I have in the jar. It seems to me like with 3/4 of an inch or an inch of yeast cake in the bottom of a pint jar, a 1 quart starter would probably do it but, I'd really like your input.

I'm here, doing some off the cuff calculations about the cell count in your top cropped slurry, then got interrupted.
Man, I miss Mr.Malty...

Similar to what @DBhomebrew said you need a starter. 2 liters at the minimum, IMO.

 

[slayer021175666]

I'm here, doing some off the cuff calculations about the cell count in your top cropped slurry, then got interrupted.
Man, I miss Mr.Malty...

Similar to what @DBhomebrew said you need a starter. 2 liters at the minimum, IMO.

Thanks a lot for working on it for me, like that! Okay. I'll make it 2 l starter.
I really appreciate it!

 

[slayer021175666]

Sorry but, I did mention it's for a 10 gallon recipe, right? I guess you probably knew that and that's why you suggested a 2 L instead of 1L?

 

[IslandLizard]

Sorry but, I did mention it's for a 10 gallon recipe, right? I guess you probably knew that and that's why you suggested a 2 L instead of 1L?

Yes, at minimum.
Much depends on the gravity of that 10 gallon batch.

Is that a stir plate or s-n-s starter?

 

[slayer021175666]

Yes, at minimum.
Much depends on the gravity of that 10 gallon batch.

It's another 10:56 or 1060 at the most.

 

[DBhomebrew]

10 gallon recipe,

Ah. I amend my "Go for it" to "Go for it x2".

 

[slayer021175666]

 

[IslandLizard]

Ale, right?
If so, you'd need 392 billion cells... or thereabout, per Homebrew Dad's Yeast pitch Calculator.

How much liquid do you think is mixed into that yeast?
50% yeast solids, 50% liquid?

 

[slayer021175666]

Ale, right?
If so, you'd need 392 billion cells... or thereabout, per Homebrew Dad's Yeast pitch Calculator.

How much water do you think is mixed into that slurry? 50/50?

I don't really know. It's set in the fridge for a month. It was pretty compact, I would say. Maybe that will give you some idea of how much it might be.
Yes. Ale.

 

[passedpawn]

Not unusual. If it's less than 3 months old, and the yeast was covered by beer, use it.

Yeast is one place you don't mess around, but if you saved it from a previous fermentor, and it's not too old, it's low risk.

 

[IslandLizard]

I don't really know. It's set in the fridge for a month. It was pretty compact, I would say. Maybe that will give you some idea of how much it might be.
Yes. Ale.

As long as that sediment layer (yeast solids) in that pint jar was around 3/4"-1" you're in good shape.
You do need a 2 liter to starter to bring it up to around 392 billion cells (quadrupled).

Here are my calcs:
Having about 3/4" - 1" of thick sedimented slurry in a pint Mason jar translates into around 75-100 ml of (prime, top cropped) yeast slurry.

Generally, 40-60% yeast solids will correlate to 1.2 billion cells per ml.*
So you've got 90-120 billion cells in there. Likely a bit better, due to it being top cropped (far less trub %).

* Source: Professional | Yeast Harvesting & Repitching - Wyeast Lab

 

[slayer021175666]

As long as that sediment layer (yeast solids) in that pint jar was around 3/4"-1" you're in good shape.
You do need to starter to bring it to around 392 billion cells (quadrupel).

Here are my calcs:
Having about 3/4" - 1" of thick sedimented slurry in a pint Mason jar translates into around 75-100 ml of (prime, top cropped) yeast slurry.

Generally, 40-60% yeast solids will correlate to 1.2 billion cells per ml.*
So you've got 90-120 billion cells in there. Likely a bit better, due to it being top cropped (far less trub %).

* Source: Professional | Yeast Harvesting & Repitching - Wyeast Lab

I already started a 2 l starter. I hope you're not telling me that I needed to make a 1 l, now?

 

[IslandLizard]

I already started a 2 l starter. I hope you're not telling me that I needed to make a 1 l, now?

Sorry, I forgot to mention the starter size. I edited, it's a 2 liter starter, indeed.
That should get you in the 392 billion cell ballpark.

 

[passedpawn]

I already started a 2 l starter. I hope you're not telling me that I needed to make a 1 l, now?

If you're pitching from a mason jar of saved yeast trub, and it's not too old, I would not bother with a starter. Just dump it into the fermentor.

 

[DBhomebrew]

Not trub, top cropped yeast. I wouldn't think twice about pitching a month old 1" of top cropped yeast into a normal gravity 5G. For 10G, a quick liter SNS would probably be effective. I regularly pitch 500ml SNS starters into 4G up to and including 1.100 with very good results. Note, I don't count or estimate cells. 2L will be plenty and it's near impossible to overpitch. An underpitch by half would only add ~90m to lag time.

TL/DR Pitch healthy active yeast. Relax, have a beer, etc.

 

[slayer021175666]

Starter has been sitting for 16 and 1/2 hours. No perceivable activity yet. Haven't tasted it but, I don't see any foam and all the yeast is just sitting on the bottom of the wort.

 

[balrog]

shaking and or stirring, right?

 

[slayer021175666]

SNS. Just stirring it up by hand every now and again when I pass by it.

 

[balrog]

Good.
My older reserved yeast pint jars take longer to get started in a starter than younger ones, but the resultant starter starts startlingly normally when used in the brew.

 

[slayer021175666]

Good.
My older reserved yeast pint jars take longer to get started in a starter than younger ones, but the resultant starter starts startlingly normally when used in the brew.

Right. I'm not real worried at this point. I would just like to brew and until I know for sure that the yeast made a good starter beer, I can't.
I was just kind of letting everybody know what's going on.