How Long Can You Leave Beer In Primary Fermentation?

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The only research that has been done is from commercial brewing (unless you count Brulosophy and other anecdotal evidence as research which I don't.)
Two weeks is regarded as the maximum, after that harm can be measured. Most of the damage comes from yeast Autolysing (autolysis literally means self eating).
When yeast autolyses it releases Nitrogen compounds mostly Ammonia based chemicals, apart from not tasting and smelling good they raise the pH of the beer which makes it less palatable. At it's worst these flavours start to taste like burnt rubber.
The other really noticeable damage comes from the release of Protease-A, an enzyme that will given time chop every protein it can find down to peptides. The first sign is a fall in the head holding ability of the beer, certain proteins (LPT1 and Protein Z in particular) are vital to head formation and retention, at extremes a loss of body and mouth feel in the beer. Call it flat and thin - not really a good look in beer.

Commercial brewers tend to pitch way bigger than home brewers do, good rule of thumb is if you haven't hit FG in 7 days you have under pitched.
This is a bit of a two edged solution, more yeast, more that can autolyse, more autolysis products.
Less yeast, slower ferments, the yeast tends to be older by the end of the ferment and more prone to breaking down, but there is less of it to do harm.

I suspect there is no way to give a definitive, perfect solutions, one of these so often brewing answers "well it all depends..."
For mine, pitch a lot of good healthy yeast, control the temperature well, if I'm going to leave the wort in primary for more than 7-10 days - rack (or drop from the cone is you are lucky enough to have a conical).

Mark
 
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The only research that has been done is from commercial brewing (unless you count Brulosophy and other anecdotal evidence as research which I don't.)
Two weeks is regarded as the maximum, after that harm can be measured. Most of the damage comes from yeast Autolysing (autolysis literally means self eating).
When yeast autolyses it releases Nitrogen compounds mostly Ammonia based chemicals, apart from not tasting and smelling good they raise the pH of the beer which makes it less palatable. At it's worst these flavours start to taste like burnt rubber.
The other really noticeable damage comes from the release of Protease-A, an enzyme that will given time chop every protein it can find down to peptides. The first sign is a fall in the head holding ability of the beer, certain proteins (LPT1 and Protein Z in particular) are vital to head formation and retention, at extremes a loss of body and mouth feel in the beer. Call it flat and thin - not really a good look in beer.

Commercial brewers tend to pitch way bigger than home brewers do, good rule of thumb is if you haven't hit FG in 7 days you have under pitched.
This is a bit of a two edged solution, more yeast, more that can autolyse, more autolysis products.
Less yeast, slower ferments, the yeast tends to be older by the end of the ferment and more prone to breaking down, but there is less of it to do harm.

I suspect there is no way to give a definitive, perfect solutions, one of these so often brewing answers "well it all depends..."
For mine, pitch a lot of good healthy yeast, control the temperature well, if I'm going to leave the wort in primary for more than 7-10 days - rack (or drop from the cone is you are lucky enough to have a conical).

Mark
My fg on day 8 (last night) was 1022, sg was 1050, need to dry hop yet as well, im hoping that when I check it tonight the gravity reading is down a few more points
 
you are using a hydrometer to do your readings?
 
Jeez. I have one on almost the same readings except after three days. Started at 1.051 pitched on Saturday around lunchtime, took a reading about an hour or so ago and it's down to 1.022. Will probably be finished tomorrow or Thursday. Similar happened on my last batch as well. Should be able to dry hop tomorrow and look to cold crash a few days later and have it in the keg next Saturday or Sunday.

I always make yeast starters, but on these last two I've done things slightly differently. First thing was making the starter a little bigger than the recommended pitch rate, and the other thing was pitching it at or a little below the fermentation temp. I'm guessing the slightly bigger yeast pitch has had more of an effect than the temperature though.
 
Jeez. I have one on almost the same readings except after three days. Started at 1.051 pitched on Saturday around lunchtime, took a reading about an hour or so ago and it's down to 1.022. Will probably be finished tomorrow or Thursday. Similar happened on my last batch as well. Should be able to dry hop tomorrow and look to cold crash a few days later and have it in the keg next Saturday or Sunday.

I always make yeast starters, but on these last two I've done things slightly differently. First thing was making the starter a little bigger than the recommended pitch rate, and the other thing was pitching it at or a little below the fermentation temp. I'm guessing the slightly bigger yeast pitch has had more of an effect than the temperature though.
Yeah I rehydrated the yeast, SG was 1050 to start, now into day 9, will dry hop tonight and take another reading then, Im hopefully bottling friday night/Saturday morning.
 
There is a world of difference between "Rehydrating" and "Making a starter".
Unless done properly rehydrating can do more harm than good, type of water, water temperature, water to yeast ratio, pitch to wort temperature... can all affect the yeast a lot more than many people would like to think. At best the yeast doesn't need to rehydrate in the wort, but it isn't actively brewing so there goes 12-24 hours.

If you gravity has only dropped 28 points (56% apparent) in eight days something isn't right, be it bad yeast handling, or most likely under-pitching (or both), poor wort nutrient, low Oxygen or any of many other causes, its under preforming pretty badly.
It would be well worth looking at your processes and seeing why.
Note that Rocker has pretty much the same gravity change (slightly more) in 48 hours, 2 days instead of 9, or something like 4.5 times faster. Odds are that his beer will taste better to (less yeast stress).
Mark
 
There is a world of difference between "Rehydrating" and "Making a starter".
Unless done properly rehydrating can do more harm than good, type of water, water temperature, water to yeast ratio, pitch to wort temperature... can all affect the yeast a lot more than many people would like to think. At best the yeast doesn't need to rehydrate in the wort, but it isn't actively brewing so there goes 12-24 hours.

If you gravity has only dropped 28 points (56% apparent) in eight days something isn't right, be it bad yeast handling, or most likely under-pitching (or both), poor wort nutrient, low Oxygen or any of many other causes, its under preforming pretty badly.
It would be well worth looking at your processes and seeing why.
Note that Rocker has pretty much the same gravity change (slightly more) in 48 hours, 2 days instead of 9, or something like 4.5 times faster. Odds are that his beer will taste better to (less yeast stress).
Mark
It was/is my 1st batch, yeast was rehydrated with boiled kettle water, 100mls at 30 degrees, I followed a youtube video to do that, as for the brew its been fermenting at 17degrees, S05 was the yeast strain used
 
Try warming it up to about 21 and see if it finishes off faster. I would have expected a pack of 05 to finish off quicker than it has though. Old or poorly stored yeast perhaps?
 
Just did another hydro reading and it has dropped to 1020 so still action happening, I only expect it to be between 1010-1014 as per the local homebrew shops expectation
 
Agreeing with Rocker, if it was a "standard" sized batch (~23L) I would expect more action.
Other than that, Please don't feel picked on, people are trying to help not to criticise.
Good to see someone using a better yeast in their first brew, you could start coming along to HUB meetings, third Friday of the month (google up Hunter United Brewers).
Might be worth telling what was in the batch, if you had lots of Maltodextrin it might be finished.
Mark
 
Agreeing with Rocker, if it was a "standard" sized batch (~23L) I would expect more action.
Other than that, Please don't feel picked on, people are trying to help not to criticise.
Good to see someone using a better yeast in their first brew, you could start coming along to HUB meetings, third Friday of the month (google up Hunter United Brewers).
Might be worth telling what was in the batch, if you had lots of Maltodextrin it might be finished.
Mark
250g maltodextrin, 250g malt extract
500g dextrose
That was a brewers blend #15
I made batch up to 21.5 litres, and used coles store bought spring water,
Also it was a mangrove jacks lager pouch that had come with starter kit
 
Good
Well that much Maltodextrin will only add about 1.004-1.005 to the FG, with what comes from the kit and the DME at a guestimate you should be finishing around 1.012-1.014.
Could easily be that as above the yeast was less than pristine, always good to look at use by, or made on dates and how your retailer looks after their yeast.

The water here in the Hunter is really good for brewing, the only thing that might need attention is Chlorine. About half a Campden tablet will take care of that, just fill the fermenter the night before add half a crushed Campden tablet, leave overnight and use the treated water to make up your wort.
Lots cheaper than spring water and like I said Hunter water is brilliant for brewing.
Mark
 
I have a beer that I would normally keg after fourteen days but I will be away for two weeks just before that time. Someone mentioned cold crashing the fermenter so that I can keg when I come back. Would that work OK?
 
I have a beer that I would normally keg after fourteen days but I will be away for two weeks just before that time. Someone mentioned cold crashing the fermenter so that I can keg when I come back. Would that work OK?
Keg it just before you leave and cold crash in the keg?
 
Keg it with the right amount of sugar, come back to carbonated beer that just needs cooling down!
Mark
 
So this morning at 7am, day 10, I dry hopped the batch, upon opening fermenter I could see action going on, still visible krausen, so i boil my hop sock for 5 minutes then sanitize with star san & add hops to the sock open the vessel and drop them in fermenter, close the lid as tight as i can and now i have air lock action again, so I think I'll still hit that 1014-1012.
 
Hopefully mate but you can disrupt suspended co2 in fermented solution and therefore some airlock action. But if there was krausen well cant deny that. Good luck on your 1st brew. You being patient itll be fine:).
 

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