Fermenting time

[MuckyNeighbour]

I started 2 x 5L stout brews on 21st & 22nd November. Brewing at approx 15 - 18C using 5g Mangrove Jack M44 yeast. One has 1kg MO, 80g chocolate malt, 108g roasted barley, 1kg Black Forest fruit mix with 200g sugar boiled down to 1kg purée and then 1kg medium spray malt added after the boil. 2nd is similar but with no spray malt. How long after apparent fermentation has ceased can I leave it before bottling? I don’t want to bottle too early in case fermenting hasn’t finished.

 

[Buffers brewery]

Hi @MuckyNeighbour . I determine the end of fermentation by taking gravity readings after about 10 days. Two gravity readings taken two days apart that are the same indicates fermentation is done.

 

[Slid]

I do 25L beers and leave them for 2wks in primary and another week racked off to secondary FV before bottling.
Fermentation is a complex process and small batches need more time.
Bottling early is always a bad move, from my experience.
Perhaps Kveik yeast might except you from this generalised rule.

 

[micklupulo]

HELP PLEASE! I have a Mangrove Jack Pils in the FV which will have been there 3 weeks tomorrow. The gravity reading seems to have stabilised at 1014 which is below the apparent target of 1015 but the airlock is periodically bubbling albeit rather feebly. The OG was 1050 and I used the MJ No1 enhancer and Harris yeast nutrient so it got off to a good start. I was away for the second week when it would have been slow as I did not set the thermostat high enough on a room heater but that still leaves two weeks at 19/20c. If the gravity is the same tomorrow it will have been stable for 48 hours so I will probably bottle it but am uneasy about the airlock activity so any comments and reassurance would be most welcome please.

 

[micklupulo]

I should add that the hops 28 gms Saaz went in at 1015 5 days ago which livened up the airlock but I would have thought the effect of the hops on this would have worn off by now.

 

[Buffers brewery]

IMO if it’s been fermenting for 3 weeks (at the desired temperature 20C?) and you get a consistent SG reading over 48 hours, it’s done. If you’re bottling you will be rousing the yeast to carbonate so I wouldn’t worry about the very infrequent bubble. Could be temperature related