Stratification after Dry Hopping

General Homebrew Discussion
1

My latest batch (American IPA) was my first where I utilized dry-hopping.  I used homegrown whole-cone hops (Centennial, Cascade, and Chinook) which were added loose to the glass carboy fermentor after beer was 95% attenuated.  At that point i had tasted the beer and was very excited, as it tasted wonderful!  I predicted that some additional hop aroma would only add to the experience.

Two days into the dry-hop, I noticed that at the beer at the top of the fermentor (starting about 1" below the layer of floating hops) was clearer than the rest of the fermentor.  I, unfortunately, didn’t snap a photo of it, but it suffices to say that the boundary between layers was quite distinct and that there was a marked difference in the amount of suspended particles.  So far this is just an interesting observation, so fast-forward to filling the keg…

I filled the keg using closed transfer methods and wound up with 0.25-0.5 gallon of residual beer which, because I was gentle when racking the it, consisted wholly of the undisturbed stratified layer I spoke of earlier.  I used this leftover beer to fill my graduated cylinder for gravity measurement and the rest went down the drain.  I took my final gravity reading, which showed an additional 0.001 of attenuation when compared to when I had dry-hopped 5 days earlier, and then took a sip of the beer from the graduated cylinder.  Ughh!..ruined!

The beer, which had tasted very good prior to dry-hopping was now a bitter mess, which I qualified as undrinkable.  It was like sucking on a grapefruit.  My wife consoled me and suggested I chill it down, burst carbonate it, and see how it faired afterwards.

I awoke the next morning with a clearer head and it was at that moment that the obvious possible explanation for the bitterness became apparent.  The upper layer of stratification that I had observed was loaded with hop constituents and did not represent the bulk nature of the brew.  I tasted the cooled and carbonated brew and found that, indeed, it was balanced quite drinkable.  Thinking about the implications led me to the following 2 conclusions and a couple of questions:

Conclusion 1):  Dry hopping does indeed impart bitterness to the beer.  I say this because the nose that I got from the ‘hop-loaded’ sample at the end of my keg transfer was not anywhere near indicative of the extreme level of bitterness that I experienced.  This is, to help qualify the statement, from an untrained palate.
Conclusion 2):  There is a propensity for dry-hop additions to remain unmixed if they are added in the form of loose whole cones.

Question 1):  Has anyone out there had a similar experience?
Question 2):  Given that I would like to promote consistency in dry-hopping and full utilization of dry-hop additions, what are some ways that you would suggest to alleviate the situation which I have observed?  I’m considering:  weighing the whole-cone hops down in a bag, using pellet hops for dry-hopping, and somehow mixing the post-dryhopped beer (not sure how to accomplish this in a glass carboy effectively…).

Thanks for the read!

2

I think you may be misinterpreting things. For one thing, I’ve dry hopped hundreds of beer and never seen that.  For another, millions of brewers through the years have dry hopped and there has never been another report of what you claim. Dry hopping certainly adds apparent bitterness,  even if if doesnt add IBUs.  I 5hink what you were eeeibbg was yeast dropping out of suspension.  Suspended yeast can definitely add a bitter flavor.

3

People call that hop bite. Bitter compounds can be attracted to the yeast.

4

I really wish that i’d taken a photo, as I’m extremely surprised that this phenomenon would be so rare.  To clarify, no pun intended, the beer was clearer at the top of the fermentor.  Maybe I’m misunderstanding, but if the yeast were the source of the bitterness, wouldn’t the lowest (first-racked and cloudiest) level of the beer be the bitterest?

5

The beer is always clearer at the top of the fermenter.

6

I have found that dropping the yeast and hop residue is very important in IPA/PA’s. The yeast bite as mentioned above along with hop debris is not pleasant, it needs to be dropped or removed.

The second thing that can add to the bitterness after dry hopping is the rise in pH. The pH can rise .2-.3 when dry hopping, making the bitterness more pronounced. If the bitterness becomes a little too sharp, I have added a small amount of phosphoric acid to the finished beer. I add just enough to get the beer down to 4.3 pH or so. It can make a big difference. If you want to experiment with acid addition in the finish beer, the easiest way is to pour a few ounces in a glass and add a drop of lactic or 85% phosphoric acid with a toothpick, typically the bitterness is reduced. If you add too much, tartness starts to show up and it’s worse than the bittering bite.

7

Am I correct in interpreting this to mean that the yeast dropped after I cooled it to serving temperature and that’s why the beer went from a bitter mess to drinkable?

8

Cold crashing will drop the yeast. Cold crashing also causes the co2 to dissolve into solution, the co2 attaches to the sharp edges of the hop residue, keeping them afloat. When the co2 dissolves into the beer there is nothing to keep the hops from dropping to the bottom.

That cleans the beer up, hops and yeast aren’t desirable in the beer.

9

Exactly.