Stuck fermentation.

[Chris P]

Well I feel like a real amateur right now. Good thing is I am.

I brewed the Mash Up kit not last Friday but the one before and it was a big learning curve/intro to BIAB. It took around 7 hours due to poor set up/not really knowing my shiz.

I mashed WAY too high (read thermometer wrong and when I used it right the mash ended up finishing around 72+deg C!) couldn't get a proper boil and then cooled it down in a bath for a bit too long. Also failed to syphon from my pot to the fermenter and so tipped a lot of the trub in (almost to the tap) Pitched my dry yeast at 22deg C and it (the temp) crashed the next day to 16 deg C. Thought it was a bad batch of yeast after raising back to 22 deg and trying to awaken the yeast failed. Pitched a rehydrated batch of US05 after this and saw some bubbling. Hydrometer has yet to move from its 1.042 mark and it started at 1.054. Hydrometer still reads correctly for water and so I feel confident it is not this. Beer samples are tasting sweet and seem to be fermenting along and changing into beer like it should. Just the reading that won't budge... Not quite sure what the next step is.

Any help appreciated =)

Chris

[Michael]

I still have brew days that take 7 hours. It depends on what I am brewing, and how well prepared I am.

I reckon the beer will finish a bit high due to the high mashing temps.Having said this, 1.042 is still a bit high. Try the following.

1) Give the fermenter a good shake and see if this wakes it up over a day or two.

2) Pitch more yeast

3) Note that just because you do not see bubbling, that does not mean fermentation isn't happening. Has the reading been the same for 3 days or more?

[Chris P]

1. Will do

2. Has anyone pitched more than two lots of yeast (at different stages of ferment) before? Any bad effects on taste etc?

3. I get what you're saying re: not seeing bubbling... mainly thinking this is a dud due to the absolute slowness of the ferment. This (the reading) has been like this since day 6 and didn't drop at all since the second lot of yeast went in. It did seem more active but nothing (reading wise) has changed since then.

[Michael]

You will be fine if you pitch on top of the wort at this stage. The additional yeast should not hurt anything.

[jamis]

Boxing day I brewed a british ale with London ESB 1968 (mashed @ 67) which is notorious for stopping at about 1.020 and sure enough it did, so after a couple of weeks I pitched some SO4 and raised the temp to about 24 and roused it abit and it started bubling slowly for the next 2 weeks, brought the gravity down to 1.012 so that part worked, but have just tasted it, tastes abit rough, and I can taste some harsh alcohol maybe fusals from the higher temps, but I wil give it some more time and see what happens.

[Michael]

That is probably due to the higher temps I would reckon, and not just pitching more yeast. Then again, I do not like the flavor that S04 imparts, so it could be the temperature and the yeast type.

Re-pitching US05 should not cause any off flavors of its own I reckon.

[Chris P]

This has not really kicked off at all again and so I guess due to mashing too high this is the level it will stay at... Now the question I have is: Do I throw this or do I bottle it (in plastic maybe) and tuck away in the shed so if the bottles blow they don't do any damage inside?

[Liam Callaghan]

I guess you might have a little too much unfermentable sugars in there from the higher temp mash, so might end up being a little sweet to taste as it is.  Have a sample of it and see what you think.  I often have beers stop around 1.020-1.016 but I tend to brew on the malty side as I like the body and sweetness balanced with the bittering and flavours of the hops.  Not always a winner but that what you get from experimentation :p

You could always make a kilo or half a kilo of sugar syrup on the stove, leave to cool over night and add that to get the yeast moving.  Might make it a little more palatable with the additional % alcohol, balance it up a bit anyway once the yeast has converted the basic sugar.  The residual sugars will probably remain.

I'd give it a reasnable shake when you add it too, get the yeast up off the bottom and into the sugar syrup.

Bit theoretical sorry Chris but well worth a try if you think its too sweet from your initial taste.

My 2 pence worth anyway :)

[Chris P]

Haha willing to try anything to get it to ferment down. I would be stoked as to get it down near 1.020 even!

[Chris P]

Oh by the way how much sugar do you think I will need to make that much syrup? I have read up on the 2 Sugars to one cup water part of making it but not how much overall Sugar to achieve those amounts. Thanks again for the tip!

[Liam Callaghan]

I'd go with a kilo Chris and just enough water to make syrup, no more as that will water your beer a bit

[Fairlane]

If you have the patience you could try doing a rescue ferment as follows...

Instead of adding yeast to the wort:

1. select a yeast that is good fermenter of other sugars (maltose, maltotriose etc)

2. prepare a proper starter of this yeast by:

• hydrating according to instructions on yeast packet - probably 100ml water at 30 deg C
• wait 15 mins (and don't touch during this time)
• double up the volume with a sugar/water solution approximately the same gravity as your wort and also within 5 deg C to lower the temp of the starter down to 25 deg C
• wait 15 mins
• double up the volume again to lower the temp of the starter down to 20 deg C
• wait 15 mins

 

3. oxygenate the starter - even by pouring from jug to jug for 5 mins

4. add some yeast nutrients (DAP or similar)

5. add another litre or so of sugar/water solution and ferment for a day at 20 deg C.  Ensure solution is fermenting well.

6. Over the next week or two, add 1 to 2 litres (depending on how much wort you have) of the wort to this yeast starter per day (don't get tempted to add too much at once).

 

You may not want to go to this hassle but this is what I would do...

Good luck!