When does primary fermentation end?

[WelshPaul]

Hi guys, after my 15l brew of pale ale went tits-up in the FV, I have begun wondering about the different stages of fermentation. Specifically, when does primary fermentation end and secondary begin?
I noticed that when I added the yeast (Munich) to the wort, it gave a pleasant, foamy head which lasted for approximately 2-3 days before it disappeared and a sediment formed on the bottom. Is this the point at which secondary fermentation starts? If so, is this accomplished anaerobically and can the wort be transferred to a different FV for this part?
Thanks for helping to clear up some confusion.

 

[Mark1964]

basically when your hydrometer gives the lowest reading for 48 hours or more and there are no signs of fermentation ie no bubbling from airlock. I never secondary ferment goes straight in to a corny.

 

[Moley]

Secondary fermentation starts when you prime and bottle or keg.

 

[Runwell-Steve]

Primary and Secondary Fermentation often gets a bit confused. It's probably not the best terminology really.

Fermentation really happens in 3 phases.

Once you pitch your yeast the first phase is the Lag Phase, this is when the yeast is just starting to get used to the environment you have pitched it in. This usually takes less than a day when you don't see much activity.

The second phase is the Growth Phase, this is where you see activity, the yeast is growing rapidly and munching away on the sugars producing alcohol and CO2. This usually starts within a day of pitching the yeast and will last approx 4 days.

The final phase is the Stationary Phase, this takes over from the Growth Phase as the growth slows down. It is at this point the beer starts maturing and conditioning, clearing up all the nasty flavours.

You would normally keg during the Stationary phase, once the majority of the sugars have been eaten up.

Secondary Fermentation can refer to.

a) The stage where you transfer to the keg/bottle and prime, because you are having a second fermentation process.
b) The stationary phase during the initial fermentation, as some people rack of into a secondary fermenting vessel for this stage.

I prefer not to use the term Secondary Fermentation as it is a bit ambiguous.

 

[WelshPaul]

Thanks Steve, that does help to clear things up. So when the beer reaches the stationary stage, has the yeast finished its job and the beer is simply developing its flavour from that point?Can I transfer it to another vessel to get rid of the sediment or is that still needed over the next couple of weeks?

 

[Runwell-Steve]

Some people transfer to a secondary fermenter as soon as It starts to slow down, so after 3 - 4 days to remove it from the trub. I just leave all my beers in the primary fermenter for 14 days, then rack straight to keg or bottling bucket if I am going to bottle.

The yeast continues working in your beer for quite a long time, but gradually what it is doing is less and less cleaning up.

The bulk of the work has been done when you reach the stationary stage, but the yeast will still continue working conditioning the beer. There is enough yeast in suspension to do this, you don't need the trub.

 

[WelshPaul]

Brilliant advice, exactly what I was looking for!
Many thanks, mate. :