[binary visions]

So my brew was started when the weather was very nice, temperate. For the first 3-4 days, it was a constant 70 degrees in the carboy and things were bubbling merrily.

The last 3 days, the temperature has been getting steadily colder at night and now we're down to around ~63 degrees in the carboy. It has clearly slowed the fermentation down.

The OG was 1.075. I'm down to 1.026 so there has been good fermentation going on but I'm a solid 0.01 away from target FG. 4 days ago, before the temps got colder, I was at 1.033.

Will this temperature change affect the beer substantially? Or will the fermentation simply take longer? I don't see it getting much colder than ~63 degrees because the house doesn't get any colder than about that at night.

This is aside from what I could do to warm it up; I know I have options there, but I'm just wondering how much it'll affect the beer.

Should I RDWHAHB?

 

[jonKranked]

I *think* the fermentation will just take longer. I'm no expert.

The batch I have going right now is currently at 1.020, FG is supposed to be 1.012. OG was listed to be around 1.042-1.044, but actual OG was 1.048. It's been a week as of today, but there's no more active fermentation. I gave the wort a stir yesterday to try and get the yeast off the bottom, but doesn't seem like anything has kicked back in. Wort is steady at around 70° FWIW it was just a dry yeast that came with a kit, and I've heard they can be so-so. Any advice?

 

[binary visions]

Check the gravity several days in a row. If there's no change, it's probably just done.

I've talked to people who will re-pitch some yeast if the fermentation sticks but it seems like most of those don't fix it. One guy I read said he will brew another batch, and drain the stuck batch onto the spent yeast cake with good success.

Here's that thread I remembered from homebrewtalk.com:

http://www.homebrewtalk.com/f14/stuck-fermentation-repitch-97760/

 

[jonKranked]

Check the gravity several days in a row. If there's no change, it's probably just done.

I've talked to people who will re-pitch some yeast if the fermentation sticks but it seems like most of those don't fix it. One guy I read said he will brew another batch, and drain the stuck batch onto the spent yeast cake with good success.

Here's that thread I remembered from homebrewtalk.com:

http://www.homebrewtalk.com/f14/stuck-fermentation-repitch-97760/

Yea I checked the gravity over 3 days. No change. I figured it was done. Not gonna bother re-pitching yeast (not that I have any).

Next batch I'm gonna try the Wyeast liquid yeast.

 

[Pesqueeb]

BV: Low temps slow fermentation and yeast reproduction but I wouldn't worry unless you get below 55.
Jon: I'd bet your done fermenting. Given that you started a little high its not unreasonable to finish a little high. I've had mixed results re-pitching and it seems that a stuck fermentation always results in some off flavors since a stuck fermentation is often the result of a low oxygen environment. If you had a productive first couple days your probably good in that regard. I'm very suspicous of any dry yeast that comes with a kit. God only knows how old it is and the lag time is long enough to make me sweat bacterial infection.

 

[Arutha]

BV - what yeast did you use?

I would personally warm it up. Yeasts don't like to drop in temp before they are done, they can become shocked and just stop working. And it is true that many ale yeasts will work below 60 at a slow rate and finish just fine, but some are pretty finicky with temp drops.

It may finish no problem given more time.

I would not expect any off flavors due your tempature change. Most off flavors due to temp come from the first few days of fermentation so you should be fine.

I would recommend keeping some extra dry yeast around just in case something happens like this and it has appeared to stall.

On a side note dry yeast actually doesn't require oxygen unless you under pitch it by a good bit.

 

[binary visions]

BV - what yeast did you use?

White Labs WLP001

Temperatures have warmed up a little and the carboy is around ~66 now. I'm going to let it ride; the gravity is down to 1.020.

Thanks for the comments guys!

On a side note dry yeast actually doesn't require oxygen unless you under pitch it by a good bit.

It's my understanding that yeast require oxygen for reproduction but not for fermentation. So it wouldn't be that dry yeast actually don't require oxygen, but more that you can pitch huge numbers of dry yeast so they don't have to do much reproduction.

Same is true for very large starters - they wouldn't require oxygen because there is very little reproduction that's needed to ferment all of the sugars.

Am I mistaken?

 

[Arutha]

Dry yeast actually has lipids with it which typically means O2 isn't needed unless you are repitching yeast that originally started dry, at that point it would need it since they have already been used. Oh and there are some people who use a small drop of olive oil to provide these oils as opposed to O2 as well. I've seen it used in some Belgian breweries and seems to work just fine for them.

And you are right, over pitching would require less oxygen and if you are pitching on a large cake you might not need to add any oxygen.

Of course I always shake the carboy when I add yeast, I was just stating that tidbit of info. Better safe than sorry.

 

[jonKranked]

Jon: I'd bet your done fermenting. Given that you started a little high its not unreasonable to finish a little high. I've had mixed results re-pitching and it seems that a stuck fermentation always results in some off flavors since a stuck fermentation is often the result of a low oxygen environment. If you had a productive first couple days your probably good in that regard. I'm very suspicous of any dry yeast that comes with a kit. God only knows how old it is and the lag time is long enough to make me sweat bacterial infection.

Yea I figured it was done fermenting. This is gonna be my last time using dry yeast - for the reasons you listed (now bolded).

My first batch (a continental dark) has a *slightly* bitter after taste - which is more noticeable in some bottles than others. Again, I attribute this to the use of dry yeast.

And yea, my understanding is that oxygen is only needed for yeast to reproduce, not ferment. I currently brew in a bucket. Should I open it up once or twice during the first day or 2 of fermentation to let some oxygen in?

A question about liquid yeast ( like this one ) - If I purchase it and don't intend to use it immediately, can it be stored (refrigerated?) until I am ready to use it?

 

[binary visions]

Should I open it up once or twice during the first day or 2 of fermentation to let some oxygen in?

CO2 is heavier than O2. Opening the bucket won't let oxygen in. You would have to stir the mixture or use an O2 stone or something.

 

[Pesqueeb]

Yeast can survive/reproduce in a low oxygen environment, but when they do they live and reproduce anaerobicly(sp?). One of the by products of this is that the yeast produces ester’s that have/result in off flavors (typically banana or clove like).

BV: I think what you say is true but I don't know for sure what kind of volumes of yeast you'd have to pitch for that to be true. I would imagine its very unrealistic to pitch the appropriate quantities.
Jon: Liquid yeast can be stored in the fridge for quite sometime. Most yeasts will have a manufacturing/recommended use by date. I want to say that I read somewhere that after 90 days your gambling with the yeast. I'll see if I can find it when I get home.

 

[binary visions]

BV: I think what you say is true but I don't know for sure what kind of volumes of yeast you'd have to pitch for that to be true. I would imagine its very unrealistic to pitch the appropriate quantities.

Well, since reproduction is exponential, the idea is that a large starter only requires a small amount of reproduction and there is always some dissolved oxygen in the wort. Not that it requires no reproduction at all.