Reflux de-aeration and what it can do for you.

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The champagne bottle manifold keeps becoming more and more powerful as we become aware of its subtle features.  A profound feature of the manifold is reflux de-aeration.  When pressure via CO2 (or nitrogen) is applied to a liquid in the bottle, the CO2 creates a nucleation site that forces oxygen dissolved in the liquid to come out of solution.  The oxygen which is now in the head space above the liquid can then be vented when the cap is loosened.  This means that no special attention has to be given to the base liquid to remove oxygen.  When the tool is used carefully the bottles can be capped with negligible oxygen.  A simple trick to prove there is no oxygen in the neck of the bottle before it is capped is to hold a lit match in the neck and watch it quickly be extinguished due to lack of oxygen.  Commercial producers do not rely on reflux de-aeration because as production scales up other techniques to de-aerate become more viable.  On the nano-scale there is nothing more economical.

But what can this do for you?

For starters the phenomenon can give confidence to beer and wine bottlers who need oxygen to be purged during bottling.  Counter pressure bottlers often flush a bottle with CO2 before they are filled to displace oxygen in the bottle.  Reflux de-aeration produces essentially the same end result.  Good news for bottling with the manifold!

For soda or sparkling cocktail production, reflux de-aeration produces interesting phenomenons with citrus juices.  Citrus juices are well known to change markedly over time but they change in two ways for two distinct reasons.  The first change is via oxidation which produces pine-sol floor cleaner-like aromas that are widely thought of as flaws when taken to their terminal point.  The second change is via enzymatic bittering which cannot be shut off in any practical way to my knowledge.  The reflux de-aeration produced by the manifold prevents the formation of aromas related to oxidation. Enzymatic bittering in the absence of aroma flaws can be wonderfully harmonic.

Bitterness can be a pleasurable feature in carbonated beverages and we can engineer the effects of enzymatic bittering into production.  If we anticipate the effect and find that it conforms to our desired harmonies, the life span of the product increases significantly.  Bottled sparkling cocktails that we thought would have to be made and sold every day can last for weeks.

Consider Brynn Tattan’s Tiger Lilly (of Back Bar fame)

carbonated to 7g/l of dissolved CO2

1 oz. blanco tequila

1 oz. st. germain

.75 oz. aperol

.5 oz. grapefruit juice

.5 oz. lime juice

1 oz. water

Reflux de-aeration prevents the formation of oxidized citrus aromas while the enzymatic bittering of the citrus juice proceeds and stretches the bitterness of Aperol into something more akin to Campari.  The sweetness of the drink gets more gustatory-bitter contrast over time and the results are extraordinary.  To get a better sense of what the final evolved product will be like when developing bottled sparkling cocktail recipes it even makes sense to pre-bitter your citrus juice by reflux de-aerating the juice a few days in advance and using this aged juice in the prototypes.

The success and ease of the technique has proven it to be the best way to treat near all citrus juices.  Currently at the bar we juice a few days worth of lemons then bottle and de-aerate.  Lemon juice seems to be less subject to enzymatic bittering than lime juice and after even a week we could detect no oxidized aromas.  Now citrus juices can be effectively and practically preserved with no expensive and large foot print vacuum de-gassing equipment and no need to tie up freezer space.

A more thorough knowledge of reflux de-aeration through experimenting with citrus juices and bottled cocktails has made us confident enough to work with champagne magnums when they are more economically viable than 750’s.  Bottles can be maintained for weeks perfectly de-gassed and with a consistent g/l of dissolved gas so they are true to their original carbonation level.

12 thoughts on “Reflux de-aeration and what it can do for you.

  1. i’m beginning to think that if we understood reflux de-aeration better we may be able to use it to do many of the tasks people are using vacuums for.

    reflux de-aeration scales up in size better than vacuuming and the equipment is cheaper and more versatile. it may make sense as a preservation technique in many situations.

  2. pro-tip: for sparkling cocktail recipe development use reflux de-aeration to create un-oxidized but already enzymatically bittered citrus juices. that way you can immediately see how your recipes will end up after prolonged storage.

  3. Approximately how much CO2 is needed to accomplish de-aeration? I’ve read the material here multiple times and I have yet to understand where de-aeration stops and what we’d typically consider carbonation/pressurization begins.

  4. Hi Lukas.

    I’ve been de-aerating at 65 PSI such as with the green apple test and I unfortunately haven’t explored using less pressure.

    to only de-aerate (with co2), such as with citrus juice, you need room temp liquid so the gas is sort of hitting a warm wall but squishing out the oxygen. or you can use nitrogen with warm or cold liquids which is far less soluble than co2.

    so if the liquid is cold, carbonation and de-aeration (removal of oxygen) happen simultaneously. the gases more or less trade places and of course you can hold far more co2 in solution than oxygen.

  5. Stephen,

    Thank you, sir. I hadn’t considered temperature, but that makes perfect sense. I’m still scraping the rust off of those high school chem lab memories.

    I’m ordering one of your manifolds today, and am eager to get to work with it. I work at a Japanese restaurant, however, and the world of saké, shochu, etc., keeps our champagne sales to a minimum. Do you have a source for champagne bottles that you use? (Patience is not to be found among my virtues.)

    Also, what’s a man to do if he craves one of those julep strainers?

  6. Hi Lukas. I use a lot of prosecco bottles and a clear glass bottle I get from a sparkling rose. real Champagne bottles are of a higher/stronger quality and you can tell them apart by their weight. when you put them on the kitchen scale they weigh much more. because I don’t sell champagne I get them from my distributors as empty store display bottles. ask whatever distributor sells Veuve and they will certainly have them.

    I haven’t made a Julep strainer in a little while. I just keep running out of a time. I learned it all from a brilliant gorgeous metallurgist I used to date. right now all my spare time is going to the plastic foundry and all the collecting of the distillation research papers.

  7. I had considered display bottles before, but I was half-afraid that they’d use something cheaper for that application. A scale would really be all you’d need to suss it out, though, eh?

    You mentioned prosecco bottles, also. Do you reduce your pressure threshold when using them, or do you find that true champenoise fizz is overkill in a cocktail, perhaps? I don’t want to hurt anybody, you know(?) — though I might risk it in pursuit of glory.

    Lastly, I was thinking about hooking up a spray attachment to my tank and regulator setup, with the idea of dosing my opened cocktails with a little CO2 before closing them back up with the champagne stopper. Would you advise this?

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