NE Craze Tips

Not being one to drool over a NEIPA, I have not followed this thread.Some of us have had more than one off line chat about these kinds of subjects, and we always are finding parallels between the processes I work with and the brewing process.

Jack, I dont think you were being accused of misquoting unless I really missed something. It doesn't seem like there is any conflict either - I read through Ricardo's slides but have only listened to part of the presentation. So far, my take away was that the effect is small, but does tend to show up more on smaller scale for what could be a variety of reasons. The subsequent post seems to agree with that thought in general. The question seems to be about the magnitude of differences and whether they are perceptible.

I'll start with the question...why would anybody believe that hot-side oxygen exposure doesnt exist and isn't a bad thing? Oxidative reactions are like any other - they are gonna speed up if you give them energy and favorable conditions. It might be "bad" for different reasons when you take it all the way back to the mash step, but as my first mentor said "Young Mr. Rose...always remember that heat is the enemy of juice", so I reckon you can substitute beer in that statement (you'll have to imagine the thick German accent...).

Based on my juice experience and heat process effects on ready to drink juice, heat certainly accelerates hot side oxidation. I can see that quite easily by monitoring Vitamin C, and with more difficulty by measuring polyphenolic content and pigments during our hotfill process. Although I am no chemist (engineer), I have run many experiments on the effects of hot side recirculation in bottle fillers. I do not doubt that the phenomenon exists in my world, but I would agree that the effects on taste are insignificant from the consumer's perspective. I can tell immediately but I have worked with my products every day for almost 40 years now ( holy cow...) I can make the "best" product in the bottle overall with a high temp/short time pasteurization with vacuum deaeration prior to filling, and an aseptic cold fill. We run hot fill... The difference is not significant enough for us to invest millions in aseptic technology.

Ahhh...but then there is the upstream processing of the fruit to consider. We use two juicing processes. One runs at 120 F and the other at 60 F. The compositions differ significantly as the hot process extracts more efficiently. But the hot juice is less stable than the cold counterpart. The taste differs mainly due to a big difference in phenolic content. However, there is a measurable oxidative degradation in the hot juice that can be tracked thru the process. One step in each process is filtration where I recirc juice at 500 gpm. I see less phenolic oxidation in the cool process even at the filtration step where huge amounts of oxygen are introduced. Is the difference huge? Nope, but there are measurable, directional differences that are not statiscally significant.

I am convinced there is "hot side" oxidation in my processes. There are enough parallels to convince me it can take place in any process with the right chemical components in the right environment. The question becomes, for my company, whether the consumer can tell. The answer is yes and no. Yes...they can tell if we formulate with the hot juice or cold juice alone as the extremes and they taste sude by side. They pick up the flavor differences due to the compositional differences. Our sensory folk would not say it is due to the chemically measurable differences in oxidative damage accumulated through the processes.

Long winded...but the point is there are parallels here I can speak to with some degree of authority. The effects are cumulative and need to be considered at every step of my processes, both in preparation of the juice (like mashing), then again during filling where we have another hot process with oxygen involved whereas a brewer might be more concerned with total package oxygen or oxygen intrusion moving products to different vessels...whatever. In my work, We control what we can control, find improvements where we can, then hedge our bets where we can't control or improve.

So...I personally don't think there is a question whether hot side oxidation exists. No question that cold side oxidation happens. Seems to me the more pertinent question is does it matter and whats the cost of controlling it - there is a dimishing return somewhere.

Just my thoughts, and of course YMMV....

Cheers!

 

Larry, I agree with that as I stated in my above post.

Agreed as well.

Yup, as I stated previously in my above post concerning HSO/HSA:

"As Ricardo mentioned during his presentation there is no doubt that HSO/HSA occurs during the early portions of the brewing process (e.g., mashing, transfer of the mash, etc.) but the fundamental question is whether this HSO/HSA genuinely impacts the flavor qualities of the resulting beer."

Larry, did you read the Dr. Charlie Bamforth article that I linked in my previous post? If you did than you would have noted where he stated as regards beer production:

"Notwith-standing, it stands repeating that there is no unequivocal published data that establishes absolutely that efforts to lessen oxygen uptake in the brewhouse benefit the flavour life of beer."

There is indeed published data that documents that oxygen ingress during the packaging of beer is a genuine problem.

If you have data measured organoleptically which refutes the above quoted sentence from Dr. Charlie Bamforth I would be interested in reading that data.

Cheers!

 

I have nothing that refutes Dr. Banforth's statement.

What I said is we do find organoleptic differences between the hot and cold process juices we make. However, those differences can not be attributed, to nor correlated with, the chemical changes that we know are taking place (measurably) with oxidative degradation of phenolic compounds being one of the things we can detect and quantify. The differences, rather, are attributed to the different composition of the resulting juices from the two processes. There is a measurable difference in phenolics that is not statistically significant - meaning the measured oxidation rate is slightly faster in the hot process vs. the cold. I would, frankly, expect the degradation rates to be far more different given a 60 degree difference in temperature between the two. Yet it is not. The hot process involves enzymatic digestion of the fruit - and we call it mash - that elevates the amount of phenolics we recover in that particular juice. For your Cranberry BPA, I sent you the cold version due its superior flavor, clarity, and stability. Even with the formula we worked out, you would have had a finished beer with a much shorter shelf life in terms of the juice component had I sent you the hot version.

In our finished products, we blend these two juices depending on how we use the fruit. By consumer testing and shelf life testing, we know where differences become detectable to consumers. But again, those differences can not be directly linked to the differing rates of chemical reactions taking place in the processes. We know the range for the blend where we can deliver a consistent tasting product to the consumer who is not an exper taster and rarely has two versions of rhe formula side by side to analyze critically like we do.

The biggest difference we see is in shelf life. Product made with the hot version suffer early browning of color, sedimentation of phenolics, and early organileptic flavor. Again, these can not be correlated with the oxidation taking place directly. It is a function of the elevated phenolic level, but our chemists tell us the oxidation that occurs at a statistically insignificant higher rate in the hot process can set up future deleterios reactions as rhe product ages. Since there is no way to set up a control from the process perspective, there is no valid test we can perform that implicates oxidation directly. I can't bubble nitrogen into 10,000 gallon tanks. It is simply a conclusion based on "connecting the dots" logically. We are setting the stage, so to speak. Even so, the biggest difference is in color stability and sedimentation, then taste.Yet we still can not definitively say oxidation is the root cause, but most of us simple engineers think the implication exists by the evidence we have.

I think it is prudent to avoid oxygen where possible. I think one should take reasonable steps to keep oxygen out from start to finish, but whether extraordinary efforts are required seems a bit dubious in my mind. I can't physically change that 500 gpm recirculation flow during filtration I spoke about in the previous post, but I can run my evaporators under vacuum to both lower the temp and pull out entrained air and dissolved oxygen. I can dose sufficient enzyme to minimze the reaction time. I can minimize and chill my run back flow from the hot fill fillers to minize heat accumulation. I can get the finished product cooled quickly once it is in the bottle. I can use RO in the cold process to remove half the water, then finish with a lower temp evaporator. I can dearate during the hot fill process.

The interesting slides to me in the AHA presentation are the ones that compare nitrogen vs active addition of oxygen. The control (no added oxygen or nitrogen) versus the nitrogen sparged samples showed little difference. The differences were much greater when oxygen was actively added. That slide more or less confirms what I know from my own work. If you intentionally aerate hot product, things change. We aerate wort after chilling, right?

 

I think the common thread (no pun intended) is lowering dissolved oxygen, whether it occurs on the hot side or cold side...and whether the techniques are worth the effort (above and beyond normal homebrewing O2 mitigation techniques).

 

Seems to be the case no matter what forum you post on (save your own, I imagine).

 

Looks awesome.

 

Wow. Gorgeous brew. Love the thread — so much food for thought — thx for posting.