Is it ever too late to add more yeast?

[Jordan Logo]

tried googling this answer but everyone always goes down the path of “well we need more info before we answer!”

I just simply want to know is it ever too late to add another yeast starter to your beer? If so, how many days?

 

[jack13]

tried googling this answer but everyone always goes down the path of “well we need more info before we answer!”

I just simply want to know is it ever too late to add another yeast starter to your beer? If so, how many days?

You're going to get the same response here, because the answer depends on a number of factors. For instance, it's not even clear what you mean by "too late". Too late for what? Do you mean adding yeast past this point would ruin the beer? Not get you the result you're after (but we don't know what that is)? Not attenuate your beer any further?

It's like asking "Should I buy a Chromebook?". Someone COULD answer yes or no, but such an answer would be meaningless, as it totally depends on how you use a computer. For some, it's perfect and buying anything more expensive would be a total waste of money and would thus be an excellent choice; for others, it would be completely useless and thus a terrible choice.

I think the problem is that you're asking for a simple answer where a simple answer would be meaningless.

 

[Silver_Is_Money]

Late yeast additions should be dry yeast poured straight from the pack, as liquid yeast requires aeration, and late stage aeration leads to oxidized beer.

 

[cactusgarrett]

+10 to what @jack13 said. Let's start at the beginning:

• What problem are you trying to solve by adding an additional pitch of yeast?
• How far along is your beer?
• What are the circumstances you're experiencing? Or what is the hypothetical if you're asking in general?

 

[Jordan Logo]

You're going to get the same response here, because the answer depends on a number of factors. For instance, it's not even clear what you mean by "too late". Too late for what? Do you mean adding yeast past this point would ruin the beer? Not get you the result you're after (but we don't know what that is)? Not attenuate your beer any further?

It's like asking "Should I buy a Chromebook?". Someone COULD answer yes or no, but such an answer would be meaningless, as it totally depends on how you use a computer. For some, it's perfect and buying anything more expensive would be a total waste of money and would thus be an excellent choice; for others, it would be completely useless and thus a terrible choice.

I think the problem is that you're asking for a simple answer where a simple answer would be meaningless.

+10 to what @jack13 said. Let's start at the beginning:

• What problem are you trying to solve by adding an additional pitch of yeast?
• How far along is your beer?
• What are the circumstances you're experiencing? Or what is the hypothetical if you're asking in general?

I accidentally only pitched a starter of 500ml instead of 1000ml ): my gravity has been stable at 1.038 for about 3-4 days now from 1.048. I’m 99% sure I underpitched.

I pitched my starter about 7-8 days ago btw. Should I listen to above and just pitch some SAFALE 05 or something instead of more liquid yeast?

 

[RPh_Guy]

I just simply want to know is it ever too late to add another yeast starter to your beer?

Here's a Simple Answer:
It's never too late. Even if you already drank the beer, just drink the yeast starter too.

I think your beer is probably stalled for reasons not related to pitch rate. Are you using a hydrometer?

 

[JimRausch]

my gravity has been stable at 1.038 for about 3-4 days now from 1.048.

Agreed, you need to do something (assuming you're using a hydrometer to take the SG, not a refractometer, right?). You could pitch a pack of US-05, but I do have to disagree a bit with Silver's statement above. If you do a starter with your original yeast strain, and pitch it at the peak of high krausen (about 12 hours) then the active starter will take off without having to reaerate the whole thing. Aeration is important for the initial replication of yeast which the active starter has taken care of.

 

[jrgtr42]

IN a case like this, I don't think it has anything to do with pitching. The yeast would have reproduced until they were happy. You would have ended up with a longer lag time before fermentation took off, and there is a chance, depending on other factors, you could end up with unwanted flavors / aromas, but if the beer was to ferment to (say) 1.015, it would do so no matter the pitch rate.
Can you provide some details as to your brew, fermentation and so on, maybe we can help figure out what happened.

 

[brownni5]

Someone I work with said he had a RIS sitting in a carboy for years - was too sweet, added a more attenuative yeast, took right off!

 

[jack13]

I accidentally only pitched a starter of 500ml instead of 1000ml ): my gravity has been stable at 1.038 for about 3-4 days now from 1.048. I’m 99% sure I underpitched.

I pitched my starter about 7-8 days ago btw. Should I listen to above and just pitch some SAFALE 05 or something instead of more liquid yeast?

More liquid yeast would be just fine, generally speaking. But is it the same liquid yeast you made the starter from? As in same type from same shipment? Maybe there's a viability issue. It's just very surprising a 500 ml starter only got you from 1048 to 1038.

 

[Jordan Logo]

Agreed, you need to do something (assuming you're using a hydrometer to take the SG, not a refractometer, right?). You could pitch a pack of US-05, but I do have to disagree a bit with Silver's statement above. If you do a starter with your original yeast strain, and pitch it at the peak of high krausen (about 12 hours) then the active starter will take off without having to reaerate the whole thing. Aeration is important for the initial replication of yeast which the active starter has taken care of.

IN a case like this, I don't think it has anything to do with pitching. The yeast would have reproduced until they were happy. You would have ended up with a longer lag time before fermentation took off, and there is a chance, depending on other factors, you could end up with unwanted flavors / aromas, but if the beer was to ferment to (say) 1.015, it would do so no matter the pitch rate.
Can you provide some details as to your brew, fermentation and so on, maybe we can help figure out what happened.

More liquid yeast would be just fine, generally speaking. But is it the same liquid yeast you made the starter from? As in same type from same shipment? Maybe there's a viability issue. It's just very surprising a 500 ml starter only got you from 1048 to 1038.

Brewing a Belgian Wit that I’ve brewed just before this one except it was only a 2.5g batch. Took a slurry from the past brew and created a 500mL starter as I thought it would be enough. Fermentation usually completes within 10 days so on the 5th, 6th, and 7th day I checked the gravity using a refractometer (with conversion) and they all read the same. I’m pretty sure I just underpitched. Glad to know I can use more yeast!

 

[Comfort_Zone]

I have a hard time believing that you have a stalled fermentation at that gravity. Unless you mashed too high even an old pack of yeast would attenuate that with no trouble at all.

 

[Jordan Logo]

I have a hard time believing that you have a stalled fermentation at that gravity. Unless you mashed too high even an old pack of yeast would attenuate that with no trouble at all.

Hmmm... I mashed at 152° for 90mins then sparged at 168°.... maybe I’ll pick up another hydrometer. I broke mine a few weeks ago and just stuck with my refractometer and used a conversion calculator.

 

[JimRausch]

on the 5th, 6th, and 7th day I checked the gravity using a refractometer (with conversion) and they all read the same.

Check the SG with a hydrometer before doing anything else. I'm not sure how accurate those conversion tables are when alcohol is present.

 

[Comfort_Zone]

Hmmm... I mashed at 152° for 90mins then sparged at 168°.... maybe I’ll pick up another hydrometer. I broke mine a few weeks ago and just stuck with my refractometer and used a conversion calculator.

How accurate is your thermometer? I mean there's no harm in adding more yeast, I wouldn't even bother with a starter if you've actually only gone down 10 gravity points that's less than 1.5% abv.

 

[Jordan Logo]

Check the SG with a hydrometer before doing anything else. I'm not sure how accurate those conversion tables are when alcohol is present.

You're right... today I bought a new hydrometer and checked my FG and it read 1.018. Glad I didn't add more yeast! Now I know not to trust my refractometer for FG... hey, at least I can still use it for OG

Thanks for the help everyone! Not only did I learn that adding more yeast isn't harmful (in cases of under pitching), but I also learned a refractometer+conversion calculator is NOT accurate (BTW I was using the BeerSmith calculator - not that BS is crappy - I love BS and will continue to use it!)

 

[JimRausch]

There should be a banner headline somewhere on the forum (or maybe everywhere on the forum):
DON'T TRUST A REFRACTOMETER AFTER YOU PITCH YOUR YEAST!

 

[BrewnWKopperKat]

Now I know not to trust my refractometer for FG... hey, at least I can still use it for OG

There's a meme floating around that one can use a refractometer to determine that fermentation has stopped (stable readings from the refractometer). Combine that with an appropriate number of hydrometer measurements (1? 2?) to know that fermentation has completed in the anticipate range for the recipe.

@dmtaylor has written some excellent posts on using refactometers to determine FG (using conversion software). I'm not sure where his most recent writeups might be, but maybe he'll stop over here with a couple of links.

 

[jrgtr42]

I found a decent conversion on Brewer's Friend. With an accurate OG, it'll calculate out the refractometer reading within a point or 2 of hydrometer.
I double checked it the first few brews since I got the refractometer with the Hydrometer, and it came out right, so the only time I'll use the old one is if something doesn't sound right - and it's always been operator error.

 

[Silver_Is_Money]

There should be a banner headline somewhere on the forum (or maybe everywhere on the forum):
DON'T TRUST A REFRACTOMETER AFTER YOU PITCH YOUR YEAST!

The Novotny quadratic method for refractometers gives me excellent results when compared with a hydrometer. The trick is to determine your actual wort correction factor. That, plus one must always totally ignore the SG scale of the refractometer and look only at its Brix scale.

 

[Beer Nuts]

I just simply want to know is it ever too late to add another yeast starter to your beer? If so, how many days?

Not sure what or why you are asking.
Dump in more yeast. Observe. Report back.

It's just beer.

 

[dmtaylor]

There's a meme floating around that one can use a refractometer to determine that fermentation has stopped (stable readings from the refractometer). Combine that with an appropriate number of hydrometer measurements (1? 2?) to know that fermentation has completed in the anticipate range for the recipe.

@dmtaylor has written some excellent posts on using refactometers to determine FG (using conversion software). I'm not sure where his most recent writeups might be, but maybe he'll stop over here with a couple of links.

My favorite post of mine is here:

https://www.homebrewersassociation.org/forum/index.php?topic=28544.msg404366#msg404366

These days I find Brewer's Friend calculator to be the most accurate of all, within 0.001 specific gravity if done right.

Cheers and good luck.

 

[dmtaylor]

...And... just to pour salt on any wounds.... here's the meme I've made about this topic: