Stopping too soon

[SteveD]

This is the third fermentation in a row that's slowing down and appears to be stopping too soon.

Porter OG 1070, pitched friday night with active yeast starter, good head formed within 12 hrs, going mad by 18hrs. Fermentation temp in the range 17-20c . Monday, head collapsing and yeast settling out. Monday evening virtually stopped. G28! Because it was in an open bucket (as per pics on Porter brew day thread) I racked it into a secondary FV under airlock. Getting a bubble per 15secs at the moment, and I can see that more yeast is settling out.

Ph of the wort was about 5 out of the mashtun, Whirlfloc used to help break in boil, fair ammount of break material left in boiler, not too much in FV. Yeast was 2x sachets of Nottingham rehydrated, and started with wort (as per pics) The two previous brews also stopped a little too soon IMO

S-04 OG 1053 stopped at G15
Windsor OG 1051 stopped at G18 ( both tested after a month in barrel)

Not too too bad, but G28 is taking the piss.

What I maybe should have done is ferment from the outset in an airlockable FV. I'd have just let it keep going and see what happens, but, I was worried about the lack of CO2 blanket in the bucket so I racked it.

Still, I wouldn't have expected the slowdown to have happened at 1028! That's about 5.6% alcohol, not enough to upset the yeast just yet, I'd have thought!

At this rate I don't think it's going to be approchable by 27th March...

Any ideas on (a) possible causes, and (b) how to fix it.

Cheers,

Steve

[Andy]

What temp is it currently sitting at Steve ?

[SteveD]

What temp is it currently sitting at Steve ?

When I racked it it was at 18c. I've left it out of the water jacket so I expect it will be at ambient. 20c ish. I thought that letting the temperature rise a bit might help.

[tubby_shaw]

This may be a complete load of 4R5E but, whilst I was trawling the 'net searching for info on Free Amino Nitrogen I came upon an article (which I foolishly didn't bookmark) which said that excessive trub removal, especially cold break material can lead to slow and stuck fermentations
It read like cr4p until I thought about Andy's racing fermentations and the fact that he uses a CFC and that his cold break material ends up in his FV.
From the pictures that you posted it appears that you go to great lengths to leave all the break material behind.
Coincidence ?
Any comments from other CFC users ?
I am a IC user and my ferments tend to follow the pattern described by SteveD, which is why I use a secondary.

[Seveneer]

1.070's a big beer Steve.

When I did my Christmas special last year it started off at 1.070ish. I racked to secondary after 1 week then racked again at 8 weeks and then again at about 16 weeks. It was only at that point that yeast stopped dropping out.

Probably if I'd left it in primary for 3 weeks before racking it may have finished earlier but it got there in the end.

So, I don't think it'll be ready by the end of March but you may be lucky two months later

/Phil.

[SteveD]

I hear what you're saying about racking into secondary slowing things down. Wheeler reckons half gravity is about right, or when the ferment just goes anaerobic. But my point is that I racked because it had already slowed down, not that it slowed down because I'd racked. It had slowed right down in the primary. The appearance of the surface, and the frequency of bubbling was what you normally get when near proper racking gravity - ie virtually game over and I was getting worried about the lack of CO2 protection, so I slung it into the secondary to give me time so sort out a remedy.

Tubby Shaw - I wondered about the lack of protein due to removal of trub. Would a pinch of yeast nutrient help?

Daab - so, try rousing it - gently stirring without getting oxygen in and repitch with another yeast if that doesn't work?

[SteveD]

1.070's a big beer Steve.

When I did my Christmas special last year it started off at 1.070ish. I racked to secondary after 1 week then racked again at 8 weeks and then again at about 16 weeks. It was only at that point that yeast stopped dropping out.

Probably if I'd left it in primary for 3 weeks before racking it may have finished earlier but it got there in the end.

So, I don't think it'll be ready by the end of March but you may be lucky two months later

/Phil.

So, you're saying just leave it and eventually it will quietly ferment out? Probably, with enough time.

One of the reasons I picked Nottingham was for its resonable degree of attenuation. I thought that if it dropped it to G18 within a week I might stand a chance of having it tasteable by 27th March. Then H&G were late, and now this.....no chance. Now I'm stuck with nothing to bring unless I can get a quick low gravity ale brewed on Saturday, have no problems AT ALL with any stage of the subsequent process, and it drops bright like its life depends on it.......where did I put that isinglass. Ahhh in the airing cupboard

[Andy]

Steve - get some Hogs Back yeast for the fallback brew

[SteveD]

Daab - so, try rousing it - gently stirring without getting oxygen in and repitch with another yeast if that doesn't work?

Yep, resuspend the yeast, no need for o2 after the adaptive phase, the trouble is the yeast usualy floccs out once it's had enough so if it's dormant it cant mop up any o2 so oxidation is a problem. A high alcohol wine yeast might be the more sure fire option due to its tollerance of high alcohol levels.

but..it's not that high. 1070 isn't beyond the capability of any ale yeast I can think of. If it were an imperial stout or barley wine with OG(telephone number) I'd agree wholeheartedly. But at the moment it's about 5.6% alc in there. Would a high alcohol tolerance ale yeast be a better option at first? (when David Line was around we didn't have them readily available)

It's running at 4 bubbles/min. Is it worth waiting for a bit, or is that a neglible level of activity and I should act now?

[SteveD]

Steve - get some Hogs Back yeast for the fallback brew

I will. I'll ring them this week and collect it Saturday morning, then pop in on Danny and Di. Meanwhile the HLT will be on a timer and be ready when I get back.

[tubby_shaw]

Steve,
A pinch of yeast nutrient will certainly not hurt, as you say the drop in attenuation has only produced a modest amount of alcohol so far, so that should not have caused the yeast to stop.
You mashed at 66º C so there shouldn't be massive amounts of dextrins.
There were certainly plenty of viable yeast cells at the start of fermentation so that shouldn't be the problem.
You haven't let the yeast get to the extremes of temperature.
I think you either need to be patient and accept that it's not going to be ready for your next meet (but it should be a hell of a beer for the one after that) or add a little yeast nutrient and cross your fingers

[SteveD]

Thanks for your suggestions. Here's what I'm going to do. It's a combination of all of it.

(1) Accept it's not going to be ready by next meet. To be honest, I never said it would be 'ready' as such - that would take 6 months for something like this - but I did want it clear and carbonated, ie at least tasteable, Then I'd have brought it back 2 months later to see how it had progressed.

(2) Leave it for a bit at ambient room temp 19-22c. I'm a believer in leaving things alone to get on with it if at all possible. If the bubbling rate doesn't drop then I'll continue to wait.

(3) If it continues to slow up, rouse.

(4) If that doesn't work, rehydrate a high alcohol tolerant ale yeast, 3 or 4 packs, work up a starter to get a resonable cell count, let it settle out, pour of the gakky liquid and pitch the slurry together with a pinch of yeast nutrient.

(5) Wait some more

I can't think of anything else I could do. At least now that it's under lock, I don't have to rush.

[maxashton]

Wouldn't the wine yeast have a negative effect on the flavour of the beer?

And as everyone in their right mind (and some who aren't) have pointed out.. hell of a beer.

[SteveD]

Underpitching. Could be. It did go off well though as you saw from the photos. I've just read something on Danstar's site that may explain, and also why repitching with more of the same might just work...

When 100 g active dried yeast is used to inoculate 100 litres of wort a yeast density of 5 – 10 million
cells per millilitre is achieved. A brewer may experiment with the pitching rate to achieve a desired beer
style or to suit processing conditions.
• Sprinkle the yeast on the surface of ten (10) times its weight clean, sterilised (boiled) water at 30 – 35°C.
(N.B.: Do not use wort or distilled or reverse osmosis water as loss in viability will result.) Do not stir.
Leave undisturbed for 15 minutes, then stir to suspend yeast completely and leave it for 5 more minutes
at 30 – 35°C. Then adjust temperature to that of the wort and inoculate without delay.
• Attemperate in steps at five minute intervals of 10°C to the temperature of the wort by mixing aliquots
of wort. Do not allow attemperation to be carried out by natural heat loss. This will take too long and
could result in loss of viability or vitality.
• Temperature shock, greater than 10°C, will cause formation of petite mutants leading to long term or
incomplete fermentation and possible formation of undesirable flavours.
• Nottingham Ale yeast has been conditioned to survive rehydration. The yeast contains an adequate
reservoir of carbohydrates and unsaturated fatty acids to achieve active growth. It is unnecessary to aerate
wort.

Thinking back, I don't think it was temperature shock, as I added wort in 3 stages, trying to minimise temp shock. Interesting where they say the wort doesn't need aeration - If that's the case, repitching with a couple of packets should kick off a normal fermentation. (afterthought....or do they mean just the wort used to start it..)

...I just looked and it's picked up a bit, 1 bubble every 11-12 secs now. Come on my son!!

[oblivious]

Not sure if this has been pointed out all ready, was the wort aerated enough?