short of target gravity and fermentation stalled

[Beersnob]

I've had this happen to me 3 times in a row now very frustrated. I have a fermenting fridge set it for 20C. I pitched the us-05 around 5pm and it was happily bubbling away the next morning. until the 3rd day and it slowed right down and stopped on the 4th. I then increased the temp to 22C to try and get it going but it didn't do anything. I've still got it in the fermenter at 22C
Would appreciate any help.


Brought 65 litres of water to 70C using LPG Burner
Stirred the water until the temp stayed at around 69C then added the bag and grain stirred until no dough balls and temp levelled at 68c. It came down to around 64C so fired it up to 68C again while constantly stirring. Put the lid back on it stayed at around 68C for the rest of the 90 minutes.
Pulled bag out volume needed to be 55 litres but was 54 litres so added another litre hot from the urn.
The pre-boil Gravity was lower than the target of 1055 so I added 500gms of white sugar to bring it up.
Added the first wort hops at 60 minutes and added the additional at their times.
The post boil Gravity was 1055. Target was 1061, would have been worse if didn't add the sugar.
The post boil volume was 47.5 litres
I whirlpooled for 30 minutes then added the hops the temperature was 80C. I whirlpooled again and left it sit for another 15 minutes. Then racked to fermentor . Temp into fermentor was 20C but only got it to the 40 litre mark and even added some trube in fermenter

OG = 1055 should have been 1061
FG = 1020 should have been 1013

recipe I used below





American IPA (14 B)



Type: All Grain
Batch Size: 42.00 l
Boil Size: 54.78 l
Boil Time: 60 min
End of Boil Vol: 46.28 l
Final Bottling Vol: 39.20 l:
Equipment: 42L BIAB Oct 2015
Efficiency: 72.00 %
Est Mash Efficiency: 84.9 %:

Prepare for Brewing

• Total Water Needed: 66.69 l

Mash or Steep Grains

Mash Ingredients

Amt

Name

Type

#

%/IBU

9.00 kg

Pale Malt, Traditional Ale (Joe White) (5.9 EBC)

Grain

1

79.6 %

2.30 kg

Munich, Light (Joe White) (17.7 EBC)

Grain

2

20.4 %

Mash Steps

Name

Description

Step Temperature

Step Time

Saccharification

Add 61.69 l of water at 71.5 C

66.7 C

75 min

• If steeping, remove grains, and prepare to boil wort
• 
  
  First Wort Hops
  
  Amt
  
  Name
  
  Type
  
  #
  
  %/IBU
  
  20.00 g
  
  Mosaic (HBC 369) [11.50 %] - First Wort 60.0 min
  
  Hop
  
  3
  
  12.3 IBUs
  
• Add water to achieve boil volume of 54.78 l
• Estimated pre-boil gravity is 1.055 SG

Boil Ingredients

Amt

Name

Type

#

%/IBU

40.00 g

Mosaic (HBC 369) [11.50 %] - Boil 20.0 min

Hop

4

13.6 IBUs

2.00 Items

Whirlfloc Tablet (Boil 15.0 mins)

Fining

5

-

20.00 g

Azacca [14.10 %] - Boil 10.0 min

Hop

6

5.0 IBUs

20.00 g

Simcoe (ESB) [12.70 %] - Boil 10.0 min

Hop

7

4.5 IBUs

Steeped Hops

Amt

Name

Type

#

%/IBU

15.00 g

Azacca [14.10 %] - Steep/Whirlpool 10.0 min

Hop

8

1.9 IBUs

15.00 g

Mosaic (HBC 369) [11.50 %] - Steep/Whirlpool 10.0 min

Hop

9

1.5 IBUs

 

[mofox1]

Few things to check:
- is your temp probe accurate? If it is only out by a couple degrees then you may be nuking your beta amylase resulting in a much less fermentable wort. At 68°C you are at the higher end anyway.
- is your hydrometer accurate? Tested in 21°C(?) water for 1.000 reading (potentially test at a known sugar concentration as well)
- did you oxygenate/aerate the wort enough.. a lack of O2 will result in a lower amount of yeast produced and will cause extended ferment times... May not be the issue if the 1.020 reading was at 4 days, seems about right.
- at that OG you probably should have pitched 2 packets
- also of note could be grain age, how long ago it was cracked, how well it was cracked, yeast age... But the first four are probably more important.

Edit: Just noticed it was a double batch size... Hopefully you pitched at least 3 packets of US-05?

 

[Beersnob]

Thanks Ski
, I used a new spirit thermometer and stirred from the bottom so I think my temp reading was accurate. I use a gas ring burner to get up to temp so its a pain in the #@* to keep it at the temp accurately all the time. Maybe it did get a little to hot in some parts of the kettle not real sure.
I checked my hydrometer before using it and did find it was out by .004 but I did compensate for that. One thing I didn't do is check it with 20C water. I will do that and re-check my readings
I used an aquarium pump and air stone to oxygenate the wort while it was being racked to the fermenter through my counterflow chiller.
I pitched 2 packs of US-05. this is what my local brew shop recommended. So you think 3 should be the required amount? I Will also keep that in mind.
The grain was purchased and cracked the day before brewing.
I just checked the accuracy of my fermenting fridge with my spirit thermometer. I left it in there sitting on the fermenter for 2 hours. It seems to be reading approx 3 Deg lower than the thermostat. So, I set it originally to 20 C for fermenting but it might have only been 17C. Do you think this might have had an effect? Keeping in mind that I did turn the temp up 2 more degrees when it stalled with no effect. So was at probably 19 deg for the last 5 days.
Is there anything I could do at this stage to kick start it again?
Still frustrated about that gravity reading, I used 11.3 kg in my grain bill. plus added some sugar when realising my target was low. still way off OG target

Thanks for you input

 

[Rocker1986]

I'd say at least 3 packets, probably 4 packets for that batch size and OG. Or you could get a liquid yeast and build it up in a starter if you have the means to. Underpitching can lead to stalled fermentations.

What are you using to control the temp of the fridge? Is the temp probe for the controller attached to the fermenter or just dangling in the fridge?

You could try pitching more yeast and see if that finishes it off. Keep the temp up around that 21C mark though.

You could also do worse than to get your own grain mill. This way you can tailor the crush to suit your own system. How fine was the grain milled? Was there a lot of flour in it? I got about a 5% jump in efficiency in my BIAB system from simply adjusting my mill to crush the grains more coarsely than they had been previously. If getting your own mill isn't possible just now, maybe ask the brew shop if they can mill the grains coarser, if they are finely crushed anyway.

 

[Beersnob]

Thanks Rocker,
I used to borrow a mates mill once this could be the problem. The shops crush does seem finer than when I was doing it.
With my fermenting fridge I have 2 thermostats one for heating and one for cooling the wort is in a 60 litre fermenter with a heating pad underneath. The cooling probe is taped to the side of the fermentor, half way up the wort level and the heating probe is also taped to the fermenter about 10 cm above the heat pad.
The brew shop suggested pitching some more yeast also, hopefully there are still some fermentables to reactivate. The BS mentioned using a champagne yeast? I taste the sample I took it was way to sweet for an IPA. So hopefully yeast may work. Happy for any other thoughts.
Thanks

 

[Beersnob]

I added 2 more packs of US-05 yesterday afternoon and bumped up the temp to 22C. Unfortunately absolutely nothing's happening. Hopefully I didn't completely ruin it by adding the yeast. I honestly thought it would kick off again, the sample I tasted was still a little sweet so I'm surprised. Isn't converting it.

 

[SBOB]

this has happened on my current brew also
Did a brew with the Best Maltz Red-X malt

Was pretty close to my pre-boil gravity but for some reason my boil off was very low so missed my OG by a mile
Now my fermentation has stalled around 1.016 after the first week despite a stir up and temp raise..

Was also my first use of brought back to life frozen yeast so its possible my yeast count was down..

So, is dumping in a packet of US-05 a good idea to see if it kicks off again?

 

[Danscraftbeer]

I'll agree on yeast. It looks like you've done thorough work on everything else but yeast count is something very important and good to have an understanding of starters too, and recycling yeast is a good brewing practice to have up your sleeve. Can save quite a bit of cash on yeast that way as well.
Try Mr Malty http://www.mrmalty.com/calc/calc.html Or your brewing software and compare.

To add to that I made small starters in earlier brewing just to prove the yeast is viable because you cant really guarantee the yeast has travelled well or been handled well to have the viability it is supposed to be. Take in dates of the yeast and make the calculations.
To play the devels advocate. Yeast is always falling in viability over time even when kept refrigerated.
The quick fix for now would be to make a proven activated starter, say one packet and add it to the brew when it has an obvious growing krausen.
$0.02

 

[MastersBrewery]

As above as home brewers even those who do starters; most of us are under pitching. A standard 23Ĺ of 1050 should be getting 2 packs of yeast if not 3. At those rates you still aren't at commercial pitch rates.