I remember hearing an old Belgian brewer (perhaps Pierre Celis) say that the aroma of hops from the brew kettle is “for the neighbors.” At the seminar on how to brew with low O2 at NHC, the speaker said that all the fresh malt aroma from the boil is inversely proportionate to the malt aroma in the finished beer (not his exact words, but that seemed to be what he was saying).
What these people are saying is that if the aroma of an ingredient goes up in the steam of the brewery, then that means it will not be available in the finished product.
Does this really make any sense? Does an ingredient only have so much aroma that it can get used up in the boil?
Yes, it all makes sense to me. I am going to reduce my boiloff rate for a while to see if malt aroma especially is improved.
I don’t know. But just for balance, another old Belgian, DeClerck, rejected the idea that all hop aroma from early additions was lost, arguing that wort retained the smell of hops no matter the boil length, hence late additions, he argued, were wasteful as they yielded little bitterness and added little to aroma. So he said.
It occurs to me that the aromatic particles carried up by steam are easily detected by us. We can’t detect, with our noses, what is left in the wort, until it is later volatilized and carried by CO2 from the fermenter or our glass to our nose.
Perhaps it would require something like gas chromatography on samples at every stage of the brewing process to quantify how much of a given substance is lost or retained at each stage. (And we’d have to know just what substances make up each aroma, and I don’t think we really do yet.) What does your experience tell you, qualitatively?
I have significantly reduced my boil off rate. I notice a tremendous improvement in the quality of malt flavor – plenty of discussions out there as to why. I don’t notice any real difference in aroma.
I’ve learned some of my knowledge on my own, some from what I’ve been told, and some from just commonsense. In brewing I think you need, or should consider ALL 3.
Told: No aroma from a 60 min.
Commonsense: Might be true
Experience: brewed a helles with an ounce of 3% Hal Mit at 60 and could smell hop aroma, and it was judged as to much aroma
Let’s put the reverse idea to the test. Claim: Malt has an unlimited ability to produce malt aroma, no matter how long you boil it. Ya think?
I think the general concept it holds true. Hops are volatile and anything you smell during the boil is obviously leaving the beer. However I don’t think it’s a hard and fast rule that you lose 100% of it.
Just as a guess I would think malt aroma is less volatile than hops, since it’s more sugars and proteins than oils, so even if the inverse thing is true, there should still be a lot more malt aroma left in the beer than what you smell during the boil.
All that said, the overall aroma of the beer is going to change anyway as the yeast produce their own aroma compounds and yeast even can break down alpha acids and other hop compounds so it won’t be quite the “same”. It’s not a 1 to 1 ratio since there are complex biological reactions going on.
tl;dr - Theory has basis in some truth but not “absolute”.
I’m not sure sure about the hops thing, as I don’t make hoppy beers. But it’s certainly true for the malt. During mashing my garage used to be filled with amazing grain aroma. Since switching to Low Oxygen, there’s no grain aroma from my mash and a marked increase in grain flavor in my finished beers.
This has been my experience, as well. The aroma of mashing in and stirring the mash is reduced by gentle handling at that point, but still present; once I cap the mash and begin a closed loop HERMS recirc. (pizza pan with fittings, lock line halo below wort level and silicone hose as a gasket on the pan perimeter), I have very negligible aromatics that I perceive.
But, pkrone and ynotbrusum, see my thinking above. It does not logically follow that the aroma missing from your garage is that which you find later in your beer. Your improved process is possibly just better preserving the aroma downstream. We cannot, without more evidence, presume to quantify “total aroma potential” and how much is lost or retained in the brewhouse. I’d wager that the aroma you smell in the brewhouse is an insignificant portion of the total potential. But it’s just a guess at this point. (I feel like we’re getting into International Maltiness Factor territory here… 
)
I think that pkrone and ynotbrusum are saying that malt aromatics during wort production and malt flavor in finished beer are inversely proportional.
They can correct me if i’m wrong but what they are discussing doesn’t take into account malt aroma.
But are both dependent on the same substances? That would be my assumption. But I hesitate to assume.
Maybe?
I can also attest to the inversely proportional relationship between typical wort production aromas and final beer flavor. I would imagine that is correlated in some way to malt aromas as well. Obviously reduced boil vigor is helping out both flavor and aroma as well.
I agree with you. Correlation is not necessarily causation.
There are a number of things going on in general when you exclude oxygen in the mash as well as reduce your boil vigor, so I am in agreement with you in general: It could be the sum of all parts that improves malt flavor and aroma as well as hop flavor and aroma.
It’s hard to pinpoint exactly what’s happening when but recognizing the relationship between the absence of mash smells and preservation of flavors and aromas downstream is a good place to start.
I incorporated a few low O2 steps in a German Pils yesterday - conditioning the malt and crushing it right before mash in, pre-boiling all the liquor (mash and sparge), adding camden tablet, pumping the strike water under the false bottom into the mash tun with minimal stirring, recirculating through 3 temp steps (148F, 160F, 170F) and even adding some CO2 to the bottom of the boil kettle at the start of the sparge.
No malt aroma escaped my brewery. We’ll see if the beer has more malt flavor than my regular method.
Sounds like a good brew day.
It was a bit longer than my normal brew day. I forgot to mention the low intensity boil.
I also had to repair the house A/C, which had stopped draining water outside and filled the pan in the attic until the float switch tripped.
And I smoked some ribs.
And we went out for drinks late afternoon.
So it was a full day.
I have to say that I don’t know how much any one of the strike water preboil with mash water adjustments and mash process steps aids in the flavor profile, but I certainly believe that the combined processes have improved the flavor profile in the end for my paler beers. I was simply commenting that the aromatics are not escaping during the mash in a very perceptible way. I have applied the same techniques to other styles with a little less significant improvement to my palate, but improvement in any event. There are adjustments that arise with the process, such as lighter colored wort that I perceive to be a result of lower oxygen intrusion pre-boil and gentler boiling. Again, I cannot quantify the differences, because I have not done side by side blind triangle tests on these things - I could be biased and I readily admit that, but for my money, I am going with the preservationists on this one.
I think anytime I add a procedure in my routine I add an hour until it becomes fully incorporated. I brew less these days (about once a month) so I like to take my time and enjoy the process.
You sound like me brewing and BBQing at the same time. I position the cooker thermometer where I can see it from the brewery (aka laundry room) window. My cooker is seasoned well so it requires only one or two adjustments for energizer bunny-style marathon cooks. It is about as set it and forget it as a naturally aspirated charcoal cooker can be I guess.
…and naturally there has to be a house crisis thrown in as a stress reducer. LOL
It seems to me that there are three places that aroma can manifest itself; in the wort, in the air, and in the spent grain. After all, spent grain does have SOME aroma and flavor, unless you sparge for days on end. So, decreasing the aroma in the air doesn’t NECESSARILY increase the aroma/flavor in the wort; more may just remain in the spent grain. Maybe.