No fermentation!

Discussion in 'General Beer Brewing Discussion' started by steveng, Mar 21, 2019.

Help Support The Homebrew Forum UK by donating:

  1. Mar 21, 2019 #1

    steveng

    steveng

    steveng

    Active Member

    Joined:
    Jul 17, 2017
    Messages:
    28
    Likes Received:
    5
    Location:
    Antrim, N.Ireland
    Hi everyone,

    I've recently brewed up a Pilsner but it has not fermented at all after 5 or 6 days! I'm happy to chalk it up as a bad batch but I'd like to possibly have some idea of what went wrong, any ideas would be most appreciated!

    As I have done on a couple of brews, I finished my wort (86% Pilsner malt, 9% Munich malt, 5% acid malt), put in the fermenter and didn't do any chilling, other than place it in my fermentation chamber, set to 12 degrees C. The plan was, next morning, it'll be down to temp and I'll pitch the yeast. This has worked with great success in the past.

    Prior to all this, I'd had a yeast starter (Wyeast Czech Pils) going for 24 hours or so on a stir plate - that was this month's home brew purchase!

    So, the following morning, I went to the fridge to find that the temperature was only down to 25. As it happens, I was heading away that day, and wouldn't be back until the following day so I put starter in the fridge and thought I'll just pitch on my return, which I did.

    Five days later, I took a reading (hydrometer) and the gravity was just as I had left it (1.055) and there was no signs of life! I decided to up the temp by a couple of degrees, and then gave it a good stir to try and reinvigorate things. Nothing!

    I've come up with a couple of things that I think are potentially relevant:
    1. The yeast wasn't exactly fresh when pitched - it was about 2 and a half months since manufacture.
    2. I'd left it in the top of my fridge, still inside the packaging with an ice pack. It was very cold when I lifted it out. My fridge sometimes has a tendency to freeze things although it didn't seem solid. The smack pack didn't expand a lot, but I've had that happen before with no problems.
    3. Due to time constraints, I pitched the yeast almost directly out of the fridge - not sure whether I needed to give it time to come up to temperature a bit.

    Failing that, it could just be terrible luck and the brewing gods have decided I need a bad batch after many good ones!

    Perhaps none of that is relevant but if anyone has any pointer, I would be very grateful!

    Steven
     
  2. Mar 21, 2019 #2

    An Ankoù

    An Ankoù

    An Ankoù

    Regular.

    Joined:
    Feb 2, 2019
    Messages:
    453
    Likes Received:
    166
    Location:
    Brittany, France
    Your yeast is as dead as a dodo for whatever reason. Have you got any other yeast you can put in? Lager yeast or not.
    More worrying is that your beer's been hanging around for 5 to 6 days and is an ideal medium for infection. As it's a pilsner you possibly haven't done many late hop additions-?? I'm thinking along the lines of getting some viable yeast- a couple of packets of MJ or Fermentis saflager, bringing the wort back up to 80C to kill off any bugs, cooling it again and pitching fresh yeast.
    That's what I'd do, for what it's worth. Some might say use a campden tablet or two to kill off any bugs, but that's going to put a strain on your yeast, too.
    I wonder what others think.
     
  3. Mar 21, 2019 #3

    An Ankoù

    An Ankoù

    An Ankoù

    Regular.

    Joined:
    Feb 2, 2019
    Messages:
    453
    Likes Received:
    166
    Location:
    Brittany, France
    Oh. and you need a bacchanalia to appease the gods.
     
    steveng likes this.
  4. Mar 22, 2019 #4

    Colin Macdonald

    Colin Macdonald

    Colin Macdonald

    Active Member

    Joined:
    Mar 12, 2019
    Messages:
    20
    Likes Received:
    0
    Hopefully you rememberd to put sugar in
     
  5. Mar 23, 2019 #5

    Leon103

    Leon103

    Leon103

    Landlord.

    Joined:
    Aug 12, 2015
    Messages:
    4,824
    Likes Received:
    1,403
    How many packs of yeast did you use. You need two for a lager
     
  6. Mar 23, 2019 #6

    An Ankoù

    An Ankoù

    An Ankoù

    Regular.

    Joined:
    Feb 2, 2019
    Messages:
    453
    Likes Received:
    166
    Location:
    Brittany, France
    I've always had issues with this business of needing two packs of yeast at twice the price and I refuse to fall for this one. US homebrew recipes tend to be standardised on 19-20 litre batches so why can't Wyeast and Whitelabs put sufficient yeast in their sachets to do the job- as they do with their other yeasts? I usually use dried yeasts, either Mangrove Jacks or Fermentis and I ALWAYS rehydrate the yeast before pitching. Chris White (of Whitelabs) points out that pitching dried yeast directly into the wort will kill about half the cells. Rehydrate and you've already got a double dose, then.
    I always use a yeast for several generations so after the first beer, the yeast is already beginning to adapt to house conditions anyway and is on its way to becoming a house yeast. I suppose that if I pitched a new yeast with every beer, I might use liquid yeasts. I'm sure the manufacturers would want us to do that. Of course, there is a much greater variety of yeasts in liquid form when a "special" or one-off is being considered.
     
  7. Mar 23, 2019 #7

    stz

    stz

    stz

    Well-Known Member

    Joined:
    Jul 2, 2018
    Messages:
    172
    Likes Received:
    106
    Because of the temperature and time frame involved lager pitch rates are through the roof compared to ale.
    Personally I hate a long lag phase at the beginning because it the most risky time for wort and part of the reason for such brutal pitch rates, the other is because it'll fail to produce enough heat to sustain the fermentation, stop the yeast dropping out with a sluggish fermentation.
    You need to have cells survive all the way through to a complete and timely attenuation, cold ferment lager is a lot less forgiving than ale.
    Something like 6x10^9 cells per gram. 25 litres of wort at a starting gravity of 1.046 wants 71g at 12C and you'll need a plan to get it to attenuate the final bit if you can't keep it warm towards the end as it begins to cool off.
    If you don't want to use the baller amounts of yeast do a slightly fake style lager and pitch a 'getting away with it' amount of yeast and let it run a little warmer, when you start getting to 12C and below ferments the amount of yeast needed shoots up and up. I highly recommend this, I don't think white labs even give pitching rates for lower than 15C on their website. Practically all 'craft' lager is a compromised warm ferment compared to traditional cold ferment.

    If you are using wet and follow the "we pack 100-150 x 10^9 cells per vial" from white labs and pitch rates from someone like george fix...

    25L = 25,000ml
    1.046 = 11.5 plato
    11.5 * 1.5 (cells per ml, lager rate) = 17.25 * 10^6 per ml
    17,250,000 * 25,000= 431,250,000,000
    431,250,000,000 / 1,000,000,000 or 1,500,000,000
    2.875 - 4.3125 vials

    You should be able to see that if you goal is to do a traditional cold ferment you'll need a lot of yeast.

    Sorry OP how does this help you? You've likely pitched not enough yeast. At that temperature fermentation will be very slow and there may not even be enough yeast to finish the job. With long lag phases and fermentation times you increase the risk of contamination gaining a foothold and off flavours developing, but you don't really have anything to lose from letting it ride at this point. You could chuck a packet of something else in there. Ferment it out at 15-16C. Won't be what you wanted, but hey ho.

    Also wanted to say what is this warm ferment compromise? Well I regularly get away with s23 and 0.5 million cells per ml per degree plato which would be 24g in the 25L example given above or 0.96-1.44 vials. You might think this is still high, but it is very low compared to a cold ferment. How? Make sure you aerate your wort to the best of your ability on collection because you will need it to be on point. Collect at 20C. Pitch. Chilling on and set to 14C assuming it takes about 6 hours to drop. Don't go any lower than 14C. This should avoid a long lag phase. Typically by day 4-5 you'll be in the teens, turn off the chilling allowing the fermentation to free rise (assuming ambient isn't going to take it anywhere crazy, without heating it never really gets over 15-16C so turn heating off and set chilling to 17C if worried, though at this point less than 23C is probably no bother) seal the vessel at this point at set a relief to spund at 6-8psi, you might as well get a start on carbonation and you want positive pressure to avoid suck back on chill. You should hit terminal gravity day 6-7, worth letting it go another day or two to ensure steady reads and complete diacetyl reduction, it'll start to chill itself off. Chilling on at -3C to take it out to a total of 6 weeks though it doesn't really improve past 4. Dump the yeast over the next few days, once 90% of it is gone you can adjust the relief valve and bring up head pressure to carbonate, continue to still dump yeast every week or so.
     
    foxbat and steveng like this.
  8. Mar 23, 2019 #8

    steveng

    steveng

    steveng

    Active Member

    Joined:
    Jul 17, 2017
    Messages:
    28
    Likes Received:
    5
    Location:
    Antrim, N.Ireland
    I used a single Wyeast smack pack in a starter. If it was a simple case of not enough yeast, would I not expect to see at least some activity to begin with and then just have an incomplete fermentation?

    I've had no problem in the past with a single pack, not even in a starter, although, at about 20 litres this one is a big larger.
     
  9. Mar 23, 2019 #9

    An Ankoù

    An Ankoù

    An Ankoù

    Regular.

    Joined:
    Feb 2, 2019
    Messages:
    453
    Likes Received:
    166
    Location:
    Brittany, France
    I agree with you. There should be some activity. The yeast would be stressed, but something should happen. It my well happen yet, but how long to do want to keep your beer exposed to anything else that might get in there?
     

Share This Page