Boom and bust fermentation question - Oatmeal Stout
  • opie194opie194
    Posts: 4
    To start, this is my first time brewing, so I don't know what to expect. Everything went well the first 2 days. I poured the cooled wort to the primary fermentation bucket (cooled in 16 minutes to 82F). I then stirred the wort vigorously for a couple minutes, before I added the yeast. I used a dry yeast, but to help, I made a yeast starter. For my starter, I boiled 2/3 cup of water, then rapidly cooled it to approximately 85F. I added the dry yeast and let it sit for 25 minutes. After 25 minutes, the yeast had not foamed or bubbled. I decided to use it anyway.

    I put the lid on the fermenter (and the airlock), and let the fermentation start at room temperature (71F). After 1 day at 71F, I cooled the fermenter to 65F, and there was a lot of action (airlock was bubbling rapidly). However, on day 3 the fermenter got down to 60F, and then the airlock stopped bubbling. I brought the fermenter back up to 66F, but still no action. I know dry yeast tend to ferment fast, but I didn't think it would be that much of a boom and bust. I assume it is still fermenting, but just very slowly. The krausen has fallen back, and the residue on the side is weak.

    My hydrometer reading is 1.020.

    Do I have bad yeast? Should I pitch the yeast one more time?

    Right now my plan is to leave it in the primary fermenter for 3 or 4 more days, then transfer to secondary fermenter. Unless I need to pitch again.

    Thanks for your help.
  • ThymThym
    Posts: 121,603 Accepted Answer
    I would just let it ride. Having the temp drop rapidly can stall yeast but I doubt a 6 deg swing is going to be a problem. My beers rarely have vigorous fermentation past day 3. Just let it ride for now and check a hydro reading next week.
    The only thing between me and a train wreck is blind luck..... - Kenny
  • FerminatorFerminator
    Posts: 6,616
    I agree with lake, and unless your adding fruit or somthing I would skip the secondary and Just leave it on the yeast cake until your ready to bottle or keg.

    Good luck and let us know how it's going.
  • ThymThym
    Posts: 121,603
    @opie194 - i forgot to ask, what was you starting gravity? And what is the expected final gravity of your brew?

    oh, and an FYI on yeast prep,

    Adding dry yeast to straight water is called re-hydrating and won't create any kind of foam or action, it just gets the yeast into suspension so it's ready to rock when it his the wort.

    Proofing yeast is re-hydrating plus adding a little sugar, this should show a little foaming action if all is well. This is a quick test of viability.

    A starter is where you use a small amount of yeast and add it to a low gravity wort to step up the amount of yeast to the amount you need to pitch into your beer. This takes 24 to 48 hours to complete.
    The only thing between me and a train wreck is blind luck..... - Kenny
  • FuzzyFuzzy
    Posts: 49,656
    Lakewood said:

    @opie194 - i forgot to ask, what was you starting gravity? And what is the expected final gravity of your brew?



    also, can we assume that this is an extract batch? 1.020 might be the finished gravity. sometimes extracts don't attenuate past that point.
    The pinnacle of lame and awesome in one singular moment. -Lake
  • opie194opie194
    Posts: 4
    Thanks for the quick responses! I was worried that I had stalled the yeast by letting it get too cold too fast.

    Also, thanks for the clarification on the yeast prep. The video I watched on yeast prep was very unclear, and uninformative. Do you recommend making an actual yeast starter, just testing viability, or is just re-hydrating ok?

    As for starting gravity, I made a beginners error. I don't think I read the hydrometer correctly, but I think it was around 1.040.

    I am planning on adding vanilla to the secondary, unless it is ok to add to the primary, and I'll just leave it?
  • FuzzyFuzzy
    Posts: 49,656
    opie194 said:

    Thanks for the quick responses! I was worried that I had stalled the yeast by letting it get too cold too fast.

    Also, thanks for the clarification on the yeast prep. The video I watched on yeast prep was very unclear, and uninformative. Do you recommend making an actual yeast starter, just testing viability, or is just re-hydrating ok?

    As for starting gravity, I made a beginners error. I don't think I read the hydrometer correctly, but I think it was around 1.040.

    I am planning on adding vanilla to the secondary, unless it is ok to add to the primary, and I'll just leave it?



    if you can tell us the recipe, we can calculate the gravity. and vanilla can be added to the primary, once most of the fermentation is complete.
    The pinnacle of lame and awesome in one singular moment. -Lake
  • ThymThym
    Posts: 121,603
    As for recommendation between hydrating, proofing and making starter:
    A starter allows a small amount of yeast go further, which means less expense. This is especially true when dealling with high gravity beers, where the proper pitching volumes can be large.

    As for proofing I wouldn't bother proofing unless the yeast is of questionable heritage or past its expiry date.

    I generally don't even hydrate as that's not entirely necesarry either. Just sprinkle it into the fermenter and aerate well.
    The only thing between me and a train wreck is blind luck..... - Kenny
  • frydogbrewsfrydogbrews
    Posts: 44,679
    i always rehydrate my dry yeast in a little luke warm water for 20 minutes. it might not be necessary, but it makes me feel better and seems to begin chugging along faster than if i just sprinkled the dry stuff in. also, sometimes i will add a little "go-ferm" rehydration nutrient to my beer yeast if the SG is on the high side. plenty of nutrients in the wort, but this adds a little nutrient to the rehydration water and helps the little guys out. go ferm is almost always used for wine, cider, mead, etc....
  • opie194opie194
    Posts: 4
    I got a kit from Midwest (Irish Stout)

    Recipe -

    6 lbs dark malt extract
    4 oz chocolate malt
    4 oz 10L caramel
    4 oz Roasted barley
    4 oz Flaked Barley
    3/4 oz bittering hops
    1 oz aroma hops
    1 tsp gypsum
    Dry yeast packet

    Grains steeped in 2.5 gal of hot (~150F) water for 25 minutes
    Brought to a boil, removed from heat, added DME and gypsum (stirred for 3 minutes)
    Brought to a boil, bittering hops added, boiled for 45 minutes
    Aroma hops added to boil, for 4 minutes
    Cooled to 82F in 16 minutes, added to 2.5 gallons of water in primary (did not strain)
    Stirred wort
    Yeast added, temp at 71F
  • FuzzyFuzzy
    Posts: 49,656
    q brew gives me a gravity of 1.048 for 5 gallons. if the water volume is off, it will change the gravity, but that should be around what the og was. i'd give this a few days longer before checking again. extract sometimes takes a while to completely finish attenuating.
    The pinnacle of lame and awesome in one singular moment. -Lake
  • frydogbrewsfrydogbrews
    Posts: 44,679
    i made that exact kit for my second batch. airlock activity stopped after 2 days for me (and probably used plain old muntons dry ale yeast) wasn't taking gravity readings back then though, so who knows what the hell it finished at. tasted good, that's all that matters.
  • opie194opie194
    Posts: 4
    FromZwolle said:

    q brew gives me a gravity of 1.048 for 5 gallons. if the water volume is off, it will change the gravity, but that should be around what the og was. i'd give this a few days longer before checking again. extract sometimes takes a while to completely finish attenuating.



    Thanks, I'll let it sit for now. You all have been very helpful!
Add a Comment