How long before krausen should go down?

[TxBigHops]

So, it’s been 11 days since I brewed my first batch and I still have krausen. Seems like lots of others on here have beer ready to bottle, or rack to secondary by now. That was my original plan, to rack it today and brew my second batch. I can only brew on weekends, so I guess I will put it off another week.

Here is a photo I took this morning. Hard to tell with all the crud on the sides of the carboy, but there is still a good solid half inch of foamy krausen and I still see tiny bubbles running up the insides. I know this means fermentation is not complete yet, I just don’t recall reading any other posts where it took this long to finish.

Mostly I just want to understand what could cause this type of extended fermentation. I’m extremely detail oriented and appreciate the science of brewing.

A few facts regarding this brew:

OG: Between 1072 and 1080 (long story – but I don’t trust my actual reading)
Style: Imperial Red Ale

Yeast: WLP001

Temps: Pitched at 70, initial ferment went up to 73, I placed in a water bath with a towel on day 3 and it dropped to 63. Ferment continued fairly strongly for another day, then as airlock activity subsided our weather turned cold (for South Texas) and beer temp dropped as low as 61. Our weather has warmed and current beer temp is about 65.

 

[shtoive87]

That is certainly not done yet, as you have stated. I would guess that the yeast took time to acclimate to the new temps every time it dropped. That would result in a longer fermentation period. Also since you have a high gravity (> 1.065) beer, fermentation will take longer than normal. Wait another week or two or three. Your beer will only get better. Even when it's reached final gravity, it will clean up diacetyl and other precursors to give a better finished product.

 

[mostlynorwegian]

That looks like your local party crew is still being healthy and happy, and they are not done partying it up for you.
You have a bigger beer to begin with so there's already going to be more work for them to do and eleven days is far too short a time to get your worry on about them, or it. They'll let you know when they're done, and when that happens. Be clean. Take a gravity reading, have a sip and walk away and leave them be to clean up.
Temperatures are playing a huge role. It's a science onto its own and really I have no idea about the particulars in that science yet. Keep notes if you anticipate revisiting this beer.
The two degree jump you noticed is just the yeast having a rager and is right in line with what to expect when they figure out you got the goods they want.
But the 10 degree drop you forced on them, (and so in the middle of peak fermentation) is an interesting development which you threw their way. They'll adapt and carry on, albeit, slower with less head. Hence the drop in krausen and it'll also encourage different flavors to emerge than the 71º environment where more fruityness is expressed.
I'm currently on the other side with a beer I am forcing the issue on with room ambiense. I pitched it with an ambient temp in the mid 60s, let them do their thing for a bit, then moved it to a room that is warmer with the intent for fermentation finish up in the 70º range.
It's also a massive beer, so they will hopefully wake back up with this shift and start popping with a new intent.
Some brewers get enjoyment out of pushing, and encouraging yeast to express different flavors and aspects of what they are capable of by letting them go with whatever temperatures change happen, or if they can control it with a jacket or something. They force these changes upon them in a schedule, and with fermentable additions.
Anyhoo. Lot of info to be throwing your way.
But. You like the science of it too. Keep detailed notes, and also get reading!
Rough guess: You probably have at least another month to month and a half, or even longer to go before bottling. I'm guessing the yeast will start to fall asleep in about a week or so, and at that point. If you wish to rack to secondary. Do it. If not. Don't, and give it (in either case) another month to finish out.
Can't say. It's not my beer. Ultimately. It's your taste buds that will let you know.

 

[BigFloyd]

Those darn yeasts. Always messin with our brew schedules!

 

[BostonianBrewer]

For me two weeks primary then bottle or secondary no sooner

 

[TxBigHops]

Thanks for all the great answers / advice. I guess all I had to do was post this question, because last night when I checked the carboy the krausen was noticeably thinner, and this evening I can actually see the top of my beer in one little corner. So I'm assuming the fermentation is finally coming to a close. I'm going to plan on racking to secondary on Tuesday night, assuming the gravity reading is about right. That will be two weeks total in the carboy. Then I'll plan on 11 days in secondary and bottle on Sat Jan 25. I figure it will need 4-5 weeks of bottle conditioning and I want to serve some of it at a party on March 1.

 

[BigFloyd]

Thanks for all the great answers / advice. I guess all I had to do was post this question, because last night when I checked the carboy the krausen was noticeably thinner, and this evening I can actually see the top of my beer in one little corner. So I'm assuming the fermentation is finally coming to a close. I'm going to plan on racking to secondary on Tuesday night, assuming the gravity reading is about right. That will be two weeks total in the carboy. Then I'll plan on 11 days in secondary and bottle on Sat Jan 25. I figure it will need 4-5 weeks of bottle conditioning and I want to serve some of it at a party on March 1.

What's the actual purpose of transferring it to a secondary for 11 days?

 

[TxBigHops]

What's the actual purpose of transferring it to a secondary for 11 days?

To dry hop, and to free up the primary for another beer.

 

[BigFloyd]

to dry hop, and to free up the primary for another beer.

ok.