Double IPA primary fermentation.

[Mountainbrewer]

Hey all... Nice to be a part of this great site. i have a question. I did my first All Grain batch a week ago yesterday. Its a 5 gallon batch of double IPA. Conversion went well and i had lots o sugar, and did 8 hop additions for the boil. OG was 1.073 and it was the MOST furious primary i have ever seen. I pitched Wyeast American Ale II and had a Huge krausen in 18 hrs or so, and a second krausen in 4 days or so. Now it is day 8 and there is still a good 1.5 inches of yellow green krausen that has yet to fall back into the beer. The fermentation is ongoing, however very slow now. i see posts for folks doing Double IPA's that say two weeks in primary is standard. Any thoughts on this second krausen? I've not seen one like this in all the 30 or so partial mash - extract brews I've done. not that i remember anyway... thanks for any notes!!!

 

[Kaiser]

When you say 2nd Kraeusen, what do you mean with that. Did the 1st Kraeusen fully disappear before the 2nd Kraeusen appeared?

Kai

 

[Mountainbrewer]

not completely but it was mostly absorbed.

 

[The Brew Mentor]

What was your temperature?
Ambient or actual fermentor?

 

[Kaiser]

I think the first Kraeusen was likely from the yeast's fermentation of the simple sugar you added (glucose, fructose, depending on what you added) and then it took a while for the yeast to switch to maltose metabolism before you saw the 2nd Kraeusen. That diauxic shift, as it is called, also exists with normal wort where you have about 10% glucose. But b/c the glucose amount is so low decreased metabolism between glucose and maltose metabolism is not all that noticable.

Does the beer have increased amount of esters?

Many brewers opt to add additional sugar later during fermentation so the yeast metabolizes the more difficult to digest sugars like maltotriose before they get a load of simple sugars.

Kai