Adding more yeast after fermentation

[Jamie02173]

Ive recently brewed a porter the starting gravity was 1.062 and i used one pack of S-04 on a 25 litre batch. The final gravity should be 1.014 but its stopped at 1.020 although its only been 6 days fermenting at 18c and it seems the activity is well finished.
Im wondering could i add a half pack of dried yeast to guarantee its finished or should bottled conditioning finish it off?

 

[jtratcliff]

All grain or extract?

Extract can often end around 1.020 through no fault of your own... the 1.020 wall


e.g.
https://www.homebrewtalk.com/threads/cant-get-under-1-020-fg-wtf-am-i-doing-wrong.569848/

 

[DBhomebrew]

Adding new yeast (especially of the same strain) likely won't help.

You want your fermentation to be dead finished before bottling. Otherwise you're in for bottle bombs.

Even if it's finished, another week or three in the fermenter will do nothing but improve your beer.

 

[Jamie02173]

It was allgrain biab but no harm to leave it a bit longer i used 11g dried sachet maybe next time i should use 2

 

[RickyBeers]

Not saying it’s right, but I’ve added yeast after the fermentation was “done”.
I think it worked? It dropped the gravity… Guess it depends on how willing to experiment you are. I personally take risks often, but also have some bad beers thrown into the mix…

 

[DBhomebrew]

@Jamie02173 How are you measuring gravity?

 

[RickyBeers]

@Jamie02173 How are you measuring gravity?

Me? Tilt

 

[DBhomebrew]

It was a quick edit.

 

[CascadesBrewer]

My suggestion is to give the beer a swirl to get some yeast back into suspension (S-04 can drop out) and boost the temp. Now that I have temp control, I almost always boost my ales to around 22C to encourage them to finish out.

 

[Jamie02173]

Im measuring the gravity using a hydrometer.. i pitched at 16c and let it raise to 18 now i have it at 20c which i will leave for a few days i was thinking of adding half a sachet of us-05 i have but said id get some feeback first i also have a stout i brewed the day after with s-04 and seems like the same progress! I have not checked the stout yet

 

[Dgallo]

There’s not enough info provided by you for anyone to tell you an accurate answer. For example, is this all grain or extract. If all grain, what was the mash temp? Can you confirm that your thermometer is calibrated and accurate? How long are you currently into fermentation?

 

[SanPancho]

You have bottling yeast? Pull enough for your sample jar. Put some CBC or F2 in there, and if there’s simple sugars you’ll see activity. If not, then you mashed too high and it’s not going lower.

 

[Jamie02173]

There’s not enough info provided by you for anyone to tell you an accurate answer. For example, is this all grain or extract. If all grain, what was the mash temp? Can you confirm that your thermometer is calibrated and accurate? How long are you currently into fermentation?

I mashed at 68c for 60 minutes then 15 minutes at 75c its all grain biab and my probe is not callobrated but its a good one.. i also boil in a brew pot i have not advanced to using a grainfather yet! Its 6 days into fermentation no progress in the last 3 and i have shook it and raised the temperature.. can you tell me please what negative affects over mashing could have caused as using the brew pot is not as accurate as a grainfather!

 

[Jamie02173]

You have bottling yeast? Pull enough for your sample jar. Put some CBC or F2 in there, and if there’s simple sugars you’ll see activity. If not, then you mashed too high and it’s not going lower.

Im still a newbie!! I have us-05 dried yeast what is bottling yeast, cbc or f2?!! I could have mashed a little higher also by mistake while doing other stuff and not checking enough i was unaware of the damage it would cause

 

[Jamie02173]

This is my grain bill

 

[Beermeister32]

Relax, give it a couple more weeks for it to do it’s thing. Bring up the temperature a few degrees warmer to finish if you can. If it doesn’t come down any further, add the US-05.

Watch your mash temperatures next batch, you don’t want to prematurely denature your enzymes.

 

[Jamie02173]

Relax, give it a couple more weeks for it to do it’s thing. Bring up the temperature a few degrees warmer to finish if you can. If it doesn’t come down any further, add the US-05.

Watch your mash temperatures next batch, you don’t want to prematurely denature your enzymes.

On this occassion i got caught out its hard to keep a controlled mash using a pot and stove unless your constanly stirring and checking but i may have went a bit high on this occasion as i was aiming for a higher full body mash.. i will leave it longer and check and do some research on the information given in this post thanks

 

[Dgallo]

I mashed at 68c for 60 minutes then 15 minutes at 75c its all grain biab and my probe is not callobrated but its a good one.. i also boil in a brew pot i have not advanced to using a grainfather yet! Its 6 days into fermentation no progress in the last 3 and i have shook it and raised the temperature.. can you tell me please what negative affects over mashing could have caused as using the brew pot is not as accurate as a grainfather!

Your mash temperatures explain it to me. You mashed for 45 minutes at 154*f and then 15 minutes at 162*5. That would create a wort with a higher amount of unfermentable sugars.

There are 2 mash enzymes that turn the starches in the grain into sugars. Beta amylase and Alpha amylase. Beta amylase converts starches into highly fermentable sugars that yeast can easily it. Alpha amylase creates more complex that can’t be fermented by most brewers yeasts. Beta amylase is most effective 146-154 and alpha amylase is more effective 154-162.

This explains why your beer is almost certainly finished at 1.020 because your mash temperatures created a less fermentable wort for the yeast to consume

 

[Jamie02173]

Your mash temperatures explain it to me. You mashed for 45 minutes at 154*f and then 15 minutes at 162*5. That would create a wort with a higher amount of unfermentable sugars.

There are 2 mash enzymes that turn the starches in the grain into sugars. Beta amylase and Alpha amylase. Beta amylase converts starches into highly fermentable sugars that yeast can easily it. Alpha amylase creates more complex that can’t be fermented by most brewers yeasts. Beta amylase is most effective 146-154 and alpha amylase is more effective 154-162.

This explains why your beer is almost certainly finished at 1.020 because your mash temperatures created a less fermentable wort for the yeast to consume

I mashed at 156f for 1 hour and 15 minutes at 167f if its finished at 1.020 how will this affect my brew? Will it be sweeter the planned and will it have off flavours because of this? Thanks for the info

 

[Dgallo]

I mashed at 156f for 1 hour and 15 minutes at 167f if its finished at 1.020 how will this affect my brew? Will it be sweeter the planned and will it have off flavours because of this? Thanks for the info

It will be somewhat sweeter, have more body and less alcohol than the targeted 1.014 fg beer But no off flavors will occur from that specifically. That said 167 is hot enough to extract tannins from the grains if your ph wasn’t correct. But that’s for a different conversation

 

[Miraculix]

Wait a bit longer, raise temperature, swirl a bit, if it doesn't go lower it's done and can be bottled. Sometimes I don't understand this numbers obsession. There's no problem with a beer having a few gravity points more than expected. The really sweet tasting sugars are the shorter ones anyway, these are long gone by now.

 

[Jamie02173]

It will be somewhat sweeter, have more body and less alcohol than the targeted 1.014 fg beer But no off flavors will occur from that specifically. That said 167 is hot enough to extract tannins from the grains if your ph wasn’t correct. But that’s for a different conversation

Ph was 5.5 but its not the first time i have had this problem previo

Wait a bit longer, raise temperature, swirl a bit, if it doesn't go lower it's done and can be bottled. Sometimes I don't understand this numbers obsession. There's no problem with a beer having a few gravity points more than expected. The really sweet tasting sugars are the shorter ones anyway, these are long gone by now.

Its happened a few times before making stouts and using s-04 dried yeast but never a big problem in my eyes but a little sweeter then i expected. I wonder when bottling what the difference would be if i was aiming for 2.0 volumes surley i would not create a bottle bomb because im 6 points off the mark

 

[RickyBeers]

Sometimes I don't understand this numbers obsession. There's no problem with a beer having a few gravity points more than expected.

I agree, however I can personally relate to being concerned with gravity, an example I can think of is when I’m trying to finish a beer within an ABV bracket for BJCP Style Guidelines

 

[Miraculix]

Ph was 5.5 but its not the first time i have had this problem previo

Its happened a few times before making stouts and using s-04 dried yeast but never a big problem in my eyes but a little sweeter then i expected. I wonder when bottling what the difference would be if i was aiming for 2.0 volumes surley i would not create a bottle bomb because im 6 points off the mark

That`s why I would raise the temperature, swirl up the yeast a bit and wait a week longer. If this does not bring it down further, bottling won't either. So no problem!

Although.... I had some s04 pales that continued sloooooooowly in the bottle, the yeast just flocked out way too well to be able to finish it in the fermenter wihtin the regular speed. So these developed into gushers after some weeks. I blame the yeast on this one, or not high enough finishing temperature when yeast was still in suspension. S04 can be a bit tricky, same for A 09 Pub. All these hard floculators basically.

I agree, however I can personally relate to being concerned with gravity, an example I can think of is when I’m trying to finish a beer within an ABV bracket for BJCP Style Guidelines

I am not known to be a particular fan of bjcp "style guidelines", so I spare you my comment on that one.

 

[bwible]

My suggestion is to give the beer a swirl to get some yeast back into suspension (S-04 can drop out) and boost the temp. Now that I have temp control, I almost always boost my ales to around 22C to encourage them to finish out.

Also wouldn’t hurt to add a little yeast energizer and yeast nutrient before doing that

 

[Miraculix]

Also wouldn’t hurt to add a little yeast energizer and yeast nutrient before doing that

It actually would. This late, the yeast is unlikely to ingest all of the nutrient and you will end up having it in suspension which tastes... crappy.

 

[Jamie02173]

At this stage ill give the nutrient a miss as i did add a half sachet of yeast at the end of the boil but i should source something better! Im going to brew another porter tomorrow as i have the time and grains so hopefully better results.. i have us-05 i might try it although ive only used it for ipa and pale ale