slow fermentation at the end why ?

[Majed41]

everything is fine when fermentation start but almost all the time when it come to the end let's say 10 points from the target specific gravity it become very slow and sometimes takes days to move a point or tow . it doesn't matter what yeast type or what beer style this happen all the time

is this a lack of Nutrient ?

 

[McMullan]

Ethanol >5% starts to slow things down. If you find it’s almost grinding to halt, try pitching yeast at a higher rate next time. Yeast nutrients sometimes help.

 

[hotbeer]

Do you eat as fast when you are full instead of when you are hungry?

 

[RM-MN]

Wort isn't comprised of only one kind of sugar. When the easy sugar is gone and all that is left is hard for the yeast to digest they slow down.

 

[McMullan]

Yeast don't get full, they don't have the stomachs for it. They're voracious little multipliers. Nor do they struggle to metabolise fermentable sugars. The sequence (on average) for consuming different sugars is about biological order, in terms of efficiency, not 'difficulty'. Ethanol stress is the main factor slowing down fermentation. As a rate-limiting factor, increasing the initial yeast pitching rate is usually the solution to avoid a sluggish finish. This is why we pitch at higher rates in higher gravity worts. Apart from promoting redirection of a proportion of the metabolic output from processing sugars, ethanol interferes with the water relations of cells therefore the rate of chemical reactions generally.

 

[Kickass]

It’s common. Nothing to worry about.

 

[hottpeper13]

When my fermentations slow down ,I take that as a sign that all the esters that are gonna happen are there. So the next step is just that a step up to the top of the yeasts range to finish. There are some that will actually form another krausen.
Also a big fan of vitality pitches.

 

[McMullan]

What’s a ‘vitality pitch’?

 

[hottpeper13]

I make a starter ~1200 ml and save 250 ml for the next go around. On brew day I take a qt mason jar of wort after 10 min into the boil. Put that in the freezer and when chilled pitch it into the starter flask. I put it next to the fermenter to get to the same temp and pitch it at high krausen,generally next morning. Kveiks are much sooner. Most of the time I get a 4-6 hr lag time and an 1/8" foam cap.

 

[McMullan]

I make a starter ~1200 ml and save 250 ml for the next go around. On brew day I take a qt mason jar of wort after 10 min into the boil. Put that in the freezer and when chilled pitch it into the starter flask. I put it next to the fermenter to get to the same temp and pitch it at high krausen,generally next morning. Kveiks are much sooner. Most of the time I get a 4-6 hr lag time and an 1/8" foam cap.

Pitching freshly prepped yeast, at high krausen or within a few days of finishing, has always been considered a good practice. I’ve never heard it being called ‘vitality pitching’. Why not prep the yeast a day or two earlier then pitch once the wort is cooled on brew day?

 

[RM-MN]

I make a starter ~1200 ml and save 250 ml for the next go around. On brew day I take a qt mason jar of wort after 10 min into the boil. Put that in the freezer and when chilled pitch it into the starter flask. I put it next to the fermenter to get to the same temp and pitch it at high krausen,generally next morning. Kveiks are much sooner. Most of the time I get a 4-6 hr lag time and an 1/8" foam cap.

I put yeast right into the fermenter and let it propagate there. I get about a 30 hour lag time. So do you. You take part of the wort and pitch the yeast into that, then the next morning you pitch it into the fermeter for a 4 to 6 hour lag time...for a total of about 30 hours from putting the wort into the fermenter. I don't see how leaving the wort sit overnight helps anything.

 

[hottpeper13]

Sometimes I do pitch on brew day but most of the time (retired and kinda lazy) the boil is not over till late afternoon or evening, I'll chill to ~80 then cover and let sit till morning when it's at pitching temps. Sometimes I don't mash in till 3:00 pm,that way I can drink guilt free.
When pitched my starter is way more the beer it's fermenting then a starter wort saved from another beer. and it's not on a stir plate getting oxidized.

 

[dmtaylor]

This is another one where the answer is very simple. Patience. Don’t be in any rush. You’ll be rewarded later.

 

[Triggs1980]

I am having the opposite problem, mine doesn't appear to have kicked off as much as I was expecting. When I first sealed my bucket the air lock was going off roughly 10 times a minute but it's only been 3 days and that's dropped to maybe 3-4 times a minute. I also don't have a krausen ring. I have evidence that one tried to form around the edges, but nothing in the middle.

 

[RM-MN]

I am having the opposite problem, mine doesn't appear to have kicked off as much as I was expecting. When I first sealed my bucket the air lock was going off roughly 10 times a minute but it's only been 3 days and that's dropped to maybe 3-4 times a minute. I also don't have a krausen ring. I have evidence that one tried to form around the edges, but nothing in the middle.

1. Sealed and bucket do not often fit into the same sentence. Bucket lids often leak and some of the CO2 escapes around the lid. A very active fermentation can produce enough CO2 to make the airlock bubble even though a large percentage is leaking around the lid.

2. A krausen ring is what is left on the side of the fermenter after the fermentation has slowed and the majority of the krausen has fallen back into the beer. If you have any ring around the side of the bucket above the beer that is evidence that your beer fermented and now the yeast are doing the cleanup of intermediate products and beginning to settle out.

 

[Triggs1980]

1. Sealed and bucket do not often fit into the same sentence. Bucket lids often leak and some of the CO2 escapes around the lid. A very active fermentation can produce enough CO2 to make the airlock bubble even though a large percentage is leaking around the lid.

2. A krausen ring is what is left on the side of the fermenter after the fermentation has slowed and the majority of the krausen has fallen back into the beer. If you have any ring around the side of the bucket above the beer that is evidence that your beer fermented and now the yeast are doing the cleanup of intermediate products and beginning to settle out.

Thanks for this, very helpful. I also think I've got a problem with temperature which isn't helping. The warmest room in my house is 19oC and it probably ferments best between 25-26oC so will probably go buy a heat belt off of Amazon

 

[Miraculix]

Thanks for this, very helpful. I also think I've got a problem with temperature which isn't helping. The warmest room in my house is 19oC and it probably ferments best between 25-26oC so will probably go buy a heat belt off of Amazon

What yeast are you using? 19C room tempereature means that the liquid probably had about 23C-26C during peak of fermentation as fermentation heats up the liquid. This is actually not a good thing, unless you are using a specific yeast strain that can take such a high temperature. Fermentation temperature (note: not room temperature) between 16C and 20C for most ale strains is more common. Above 20C most of them start throwing longer (fusel) alcohols which create hangovers, even after just one or two beers.

 

[Triggs1980]

What yeast are you using? 19C room tempereature means that the liquid probably had about 23C-26C during peak of fermentation as fermentation heats up the liquid. This is actually not a good thing, unless you are using a specific yeast strain that can take such a high temperature. Fermentation temperature (note: not room temperature) between 16C and 20C for most ale strains is more common. Above 20C most of them start throwing longer (fusel) alcohols which create hangovers, even after just one or two beers.

I'm using Kveik Ale Yeast which I have just looked up and it's best between 85F-100F, so a heater it is

 

[TestTickle]

everything is fine when fermentation start but almost all the time when it come to the end let's say 10 points from the target specific gravity it become very slow and sometimes takes days to move a point or tow . it doesn't matter what yeast type or what beer style this happen all the time

is this a lack of Nutrient ?

What yeast, what temps and are you using any form of temperature control?

 

[RM-MN]

Do you have a tub the fermenter will fit in? Set it in there and put in some (sort of) hot water to bring the beer temp up.

 

[Miraculix]

I'm using Kveik Ale Yeast which I have just looked up and it's best between 85F-100F, so a heater it is

You can heat it, but it is not a must, it also works reliable at room temperature. But that yeast is the od acception. This one can take the heat.

 

[Teufelhunde]

1. Sealed and bucket do not often fit into the same sentence. Bucket lids often leak and some of the CO2 escapes around the lid. A very active fermentation can produce enough CO2 to make the airlock bubble even though a large percentage is leaking around the lid.

Depends on your buckets....I use plastic fermenter buckets from Norther Brewer. They have O-rings in the lids and seal extremely well....

YMMV

Lon

 

[hottpeper13]

With out knowing the entire recipe we don't know, but some worts will ferment out in 3 days with Kveik.