Odd fermentation

[MrAverage]

I brewed two beers in two days - an Irish Red and an Extra Pale APA. OG's were 1.047 for the Irish Red and 1.051 for the APA. I pitched one properly rehydrated fresh packet of US-05 in each batch and placed the fermentors sided by side in my 64 degree basement. The Irish Red was in a plastic bucket. The APA was in a glass carboy.

Fermentation proceeded as usual with plenty of activity in the airlocks and a thick krausen forming on the APA and, as far as I could tell, also on the Irish Red.

Seven days later, the krausen had fallen back into the Irish red and fermentation seemed to be pretty much done, with the beer beginning to clear. I transferred it to the secondary and everything seems OK.

The APA, however, still has a very thick krausen on it and the beer is very cloudy after 6 days. it looks like it's still in high ferment. However, there is no activity in the airlock.

My question is, why are these two all-malt beers with similar OG's fermented at the same temperatures with the same yeast acting so differently? Yes, I'd expect the APA to take a little longer given its slightly higher OG, but at this point I expected that the krausen would be pretty much gone and the beer pretty close to being ready to transfer to the secondary based on how fast the Irish Red fermented. After six days, the APA seems to be about where the Irish Red was in day 3 or 4 of fermentation.

I'm not worrying, but I am puzzled....

 

[Tamarack]

I'm writing b/c I saw almost 50 views and zero comments. I don't have a good answer for you and I've experience similar things myself.

On White Labs website I've read dozens of troubleshooting issues for specific yeasts and seen this issue and others like it addressed by their staff. All the logic with the different answers boils down to the fact that yeast is alive and even though their quality control is spot on, they do grow differently and might act dissimilarly. They always claim the flavor profile will be the same naturally (which I believe). Me personally, I've assumed it was at least in some small part tied to the nuances of the different ingredients. Maybe your malts are different?

I know you're not worried and I know this isn't much of an answer but I thought I'd be a soundboard for your venting.

 

[Revvy]

Since you mentioned no hydrometer reading at the time you racked, I am going to bet that you racked per calendar and not if the beer was finished fermenting. When you racked it, the yeast got all excited again and are now attempting to ferment the beer in secondary, since it wasn't finished at all in primary.

Next time don't rack too soon, if I do use a secondary, which is rare these days, I don't begin to take a gravity reading til day 10, and then at day 12, or 12 and 14 and then rack.

But nowadays you will find that few of us rack to secondary, instead we opt for a long primary, leaving our beer alone for a month, which leaves plenty of time for the yeast to actually finish fermenting, then clean up afteritself.

You'll find that more and more recipes these days do not advocate moving to a secondary at all, but mention primary for a month, which is starting to reflect the shift in brewing culture that has occurred in the last 4 years, MOSTLY because of many of us on here, skipping secondary, opting for longer primaries, and writing about it. Recipes in BYO have begun stating that in their magazine. I remember the "scandal" it caused i the letters to the editor's section a month later, it was just like how it was here when we began discussing it, except a lot more civil than it was here. But after the Byo/Basic brewing experiment, they started reflecting it in their recipes.

Where fermentation is concerned, If you arbitrarily move your beer, like to follow the silly 1-2-3 rule (or instructions that say move after a week or when bubbles slow down), you will often interrupt fermentation. Because sometimes the yeast won't even begin to ferment your beer until 72 hours after yeast pitch, so if you rush the beer off the yeast on day 7 then you are only allowing the yeast a few days to work. The problem is that yeast don't know how to read so they seldom follow the instructions. They dance to their own tune and its seldom 4 x 4 Time.

This often leads to stuck fermentation because you have removed the beer from the very stuff you need to ferment your beer. The yeast....It can often lead to the same off flavors one gets if they undrpitch their yeast.

Besides, fermenting the beer is just a part of what the yeast do. If you leave the beer alone, they will go back and clean up the byproducts of fermentation that often lead to off flavors. That's why many brewers skip secondary and leave our beers alone in primary for a month. It leaves plenty of time for the yeast to ferment, clean up after themselves and then fall out, leveing our beers crystal clear, with a tight yeast cake.

 

[ReverseApacheMaster]

There's nothing to worry about. Different beers ferment differently, even with the same yeast. Six days is not cause for concern. More to the point, sometimes krausens just don't fall. It's not a sign of anything. Your beer is done when it reaches FG with multiple readings.

 

[MrAverage]

Thanks for the responses. A few points and an update:

The beer that was racked to the secondary was the one that had appeared to be fininshed fermenting - and the hydrometer readings confirmed that it was within a point or two of the predicted FG. It's now sitting in the secondary nice and quiet and still, clearing and finishing up.

I did not rack the other one - the one with the krausen that wouldn't quit. That beer is finally showing signs of slowing down - falling krausen and darkening of the beer - after 9days in the fermentor.

tamarak's thoughts about the efects of different ingredients are interesting...except that these beers acted contrary to how my intution suggests they should if that is the case. Both beers had a base of American 2-row. The APA has about 5% light munich - nothing else. The Irish Red has a variety of specity malts - crystal, special roast, chocolate... I would think that the Irish Red would be harder for the yeast to deal with given the variety of malts, but what do I know... I guess it's just another of life's mysteries.

Again, I'm not worried, just curious about the different pace of the fermentation process with the two beers given how much they had in common.

I can say that these beer are only the second and third I've brewed using these "modern" dry yeasts. Back when I started brewing in the 1980's it was ALL dry yeast but they were very differnt from what we have now and I've been using nothng but liquid yeast for the past four years. Perhaps I just need to become familiar witht the quirks and characteristics of these yeasts.


btw - As revvy advises, I usually do not rack ales to a secondary unless I'm dry hopping or I know that I won't get to bottling for a long time (i.e. more than 3 weeks) for some reason. I've had beers in primary for up to 6 weeks and never had a problem with off flavors, so my experience agrees with the no secondary view. In this case, I needed the empty fermentor so that I could brew another batch.

Anyway, thanks for the imput. Happy brewing....