Not Just Stuck.....

[Andyd]

G'day all,

After pouring through the posts on stuck fermentations I didn't see an answer (which is not to say it's not there of course :blink:

I'm brewing one of Ross's recipes, the Vanilla Porter and have an issue. It's been in primary now for 3 weeks, and moved from the OG of 1070, down to 1040 - clearly not good...

Can't put my finger on why this has happened. The wort was aerated with a paint stirrer for 10 minutes (massive foamimg), the yeast was built up into 4L of starter (admittedly started with DME), the fermenter has been kept in a fridge at between 18 and 24 Deg C, and there appear to be no visible signs of infection. The brew tates fine (very bitter presently).

I'm contemplating pitching an alcohol tollerant strain of yeast that G&G are bringing in this week - right or wrong?

Any advice would be good...

AndyD

 

[Coodgee]

what was your grain bill? maybe that's all the fermentable sugars you converted? did you mash at a really high temperature or use alot of specialty malts or adjuncts?

 

[Andyd]

The bill was...

9.95 kg Pale Malt, Maris Otter (3.0 SRM) Grain 70.6 %
1.38 kg Brown Malt (65.0 SRM) Grain 9.8 %
1.04 kg Caramunich Malt (56.0 SRM) Grain 7.4 %
0.87 kg Munich Malt (9.0 SRM) Grain 6.1 %
0.87 kg Munich Malt - 20L (20.0 SRM) Grain 6.1 %



Andy

 

[Coodgee]

hmm, nothing wrong there. what temp did you mash at?

*note, I am no expert, have only done about 10 ag brews* just trying to help.

what about not washing out all the sanitiser properly, you might have killed too much yeast?

 

[goatherder]

Sounds like you did everything right Andy.

My only suggestion would be to sanitise a spoon and give it a stir, try to get the yeast into suspension and active again. Maybe try pitching another yeast if this doesn't have any effect after a day or two.

I don't know that an alcohol tolerant yeast will be necessary, most of your garden variety yeasts should handle a 1.070 wort.

Have you checked your hydro is reading OK, just to eliminate the obvious?

What yeast did you use?

 

[Andyd]

Thanks guys,

I've been rocking the fermenter every morning and night to try to keep it from settling out, so I don't know that a spoon would do much more than increase the risk of infection.

The mash temp was 65dC for 90 minutes, and 75dC lauter (over about an hour - seriously slow sparge & lauter).

Boiled it for 90 minutes, but struck the flame when the boiler kettle was half full, so about half the wort boiled for an additional 15 or 20 minutes.

The starter was bubbling pretty furiously for the 6 hours it took to brew - I had 2 2L conicals on a stir plate for the duration.

While the OG ws 1070, currently it's 1040 so I imagine there's a far bit of alcohol in there.

The yeast was a Wyeast Euro Ale, and I pitched 4L of yeast into 50L.

Quite a mystery...

Andy

 

[goatherder]

You mention that you had the starters going for the 6 hours of the brewday. Did you only have them going for that long?

If so, you won't have got much yeast growth in that time. The yeast will be a lot healthier than without a starter but there won't have been time for significant growth.

If this is the case, you might have been pitching a lot less yeast than you originally figured. The pitching calculator at http://www.mrmalty.com/pitching.php says you need about 5 litres of stirplate starter for this beer. You are in the ballpark for the size of the starter, but perhaps you didn't leave it long enough for adequate yeast replication which resulted in an effective underpitch. Maybe I'm clutching at straws, but it seems like you did everything else right...

 

[Andyd]

No - I started the starter Thursday night with one smack pack in 2 litres of DME wort. Friday afternoon I split that into two conicals and topped it up with fresh wort. Left it until saturday night to pitch.

The yeast was kept at 19 degrees for most of the time. The last 6 hours was out of the fridge, so it may have got a bit cooler, but it kept bubbling for the entire time.

 

[user 384]

While the OG ws 1070, currently it's 1040 so I imagine there's a far bit of alcohol in there.

I'm contemplating pitching an alcohol tollerant strain of yeast that G&G are bringing in this week - right or wrong?

Andy

A drop from 1.070 to 1.040 would mean that there is only a tad under 4% alcohol, so your yeast will not have stopped working because of this factor.

My guesses would be that one of the following has occured:

• Your hydrometer is wrong
• You thermometer is wrong and you mashed way too high
• Your yeast starter hadn't multiplied enough (yep, read your previous post but 2 days might not have been long enough)

Cheers
MAH

 

[OOlsen]

Andy,

How old was the smack pack (was it in date)?

I have had troubles getting my beer down to final, I think its because of the way I have treated my starters... Too long in storage.

Not really sure on what else to look at.....

 

[Steve]

Andy
If its being in primary for three weeks Id be racking it to secondary first up to see if that bumps it back to life....leave it a few days and take a reading. If its still at 1040 id be adding some more dry yeast.
Cheers
Steve

 

[Andyd]

Thanks again guys,

Yep - the yeast was fresh (just on one month in the pack from memory), and the Temperature guage is right (I've been calibrating a couple of them recently - all good as far as I can tell). As for the hydro, I guess it could be out, but I would be at a loss to explain why a sealed glass tube with lead weights in it should suddenly become inaccurate - although I'd love to hear from anyone who's experienced this.


Lots of good advice around - I'm planning on racking, seeing what ahppens, and if nothing's happening I'll drop in a new yeast strain (suitably started up).

MAH, you suggested that 2 days might not be long enough - over what period would you suggest stepping up to 4 L or so from a single pack?

Thanks!

Andy

 

[Darren]

Thanks again guys,

As for the hydro, I guess it could be out, but I would be at a loss to explain why a sealed glass tube with lead weights in it should suddenly become inaccurate - although I'd love to hear from anyone who's experienced this.


Lots of good advice around - I'm planning on racking, seeing what ahppens, and if nothing's happening I'll drop in a new yeast strain (suitably started up).


Thanks!

Andy

I have seen this. Once I put my hydrometer in some warmish wort probably about 40C. If id didn't hear it go "click" I wouldnt have known it had cracked. Couldn't find the crack but there was definately fluid around the bowl and did not read at all well.

Nother posibility is that the "Paper strip" inside the hydrometer can move and give false readings.

I would give the beer another week before panic. 4 litres of starter on a stir plate should be plenty.

Is the fermenter in a cool place? Might be getting a bit cool overnight.


cheers

Darren

 

[Andyd]

I've got it in a temperature controlled fridge at 22dc... so that should be ok.

I've just picked up a pack of WYeast 4366, "Distillers" yeast and put it in 1.5 L of boiled wort from the fermenter. I'll leave that till Friday and split that & top it up, then repitch on Sunday. Will let you know how it all goes.

Thanks,

Andy