Technical question regarding proof hydrometers.

Sepulchritude Forum: The Absinthe Forum Thru December 2001: Technical question regarding proof hydrometers.
By Tavarua on Wednesday, October 10, 2001 - 10:38 am: Edit

“There's enough fighting elsewhere.”

Is that a threat?

By Artemis on Wednesday, October 10, 2001 - 10:30 am: Edit

Stop fighting!!

Aion is a seeker on the path of hausgemacht, a respectful guy, a nice guy. English is not his first language, and I suspect he made that post with a large degree of tongue in cheek, but he is correct in that redistilling poor absinthe is a complete waste of time - it's easier to make good absinthe in the first place.

Wolfgang is also (as far as I know, but I don't know him as well as Aion) a nice guy, and I suspect his original post about re-distilling Deva was not serious.

There's enough fighting elsewhere. Stop it!

By Wolfgang on Wednesday, October 10, 2001 - 09:37 am: Edit

"Sorry for sounding somewhat arrogant "

Stupidly arrogant indeed...

I wonder who you are to juge yourself able to deceide what's worth talking about on this board.

Have you even drunk from the Holy Grail you'r talking about ?

I gave Deva as an exemple for my potential madman experimentation but that could have been fucking Ricard. Absolutly not related to fine absinthe.

Wolfgang - party line - Fener.

By Aion on Tuesday, October 09, 2001 - 10:24 pm: Edit

"Did someone ever tried to re-distill a bottle of Deva ?"

If you ask me, that´s not worth the time needed.
Crap remains crap.
I think no homebrewer wants his still to be contaminated.

Sorry for sounding somewhat arrogant, but you were among those who´ve tasted from the holy grail. You should know that Deva is not worth talking about.


By Dr_Ordinaire on Tuesday, October 09, 2001 - 10:46 am: Edit

Thanks, Don. The problem with asking you technical questions is that I look at a big chunk of the answers as the Taliban look at B-52s. Flying waaay over my head...

Hey, thanks for taking the time to enlighten us.

And, no, there shouldn't be anything incendiary about thujone. We can argue like theologians about how many (if any) secondary effects can dance on a T molecule, but the molecule itself is just that, a fact of life in absinthe.

I am still curious about numbers, but whatever the numbers may be they will not change the joy we get from the fairy.

By Chevalier on Tuesday, October 09, 2001 - 10:11 am: Edit

I can't remember.

By Heiko on Tuesday, October 09, 2001 - 10:08 am: Edit

I know what happened in September, but what do you mean with that static brush?

Can't have been of any significance tho...

By Chevalier on Tuesday, October 09, 2001 - 09:22 am: Edit

There's something refreshingly pre-Staticburst and pre-September 11th about this thread.

By Don_Walsh on Tuesday, October 09, 2001 - 09:13 am: Edit

Anyway thujone and anethole are not all that far apart in b.p. (c.35 C).

Also, anethole is much more soluble in water, or a medium proof water-alcohol mixture, than is thujone and that is one of the decisive factors. Were this not true, lower proof anise liquors such as anisette wouldn't be possible. The anethole would louche out. That doesn't happen, so, QED.

By Wolfgang on Tuesday, October 09, 2001 - 09:09 am: Edit

...and don't answer with the easy one : "yes and they came out with the Deva 70..." ;-)

By Wolfgang on Tuesday, October 09, 2001 - 09:06 am: Edit

By the way, is there a way to remove sugar out of a sweetened alcohol ?

Did someone ever tryed to re-distill a bottle of Deva ?

By Don_Walsh on Tuesday, October 09, 2001 - 09:05 am: Edit

Mostly because most absinthes aren't distilled at all, they are mixed up from alcohol, water, and essential oils.

Now, this is not the way I think absinthe ought to be made, or the way Ted and I make ours, but it is almost certainly the way every other commercial absinthe is built, excepting only Segarra and the La Bleues. Possibly Camargo based solely on the maker's remarks.

For all such, b.p. is not relevant.

Now, for distilled absinthes, anethole predominates because there's a lot more anethole containing herbs in the steep than there is absinthium, by a wide margin, and so there you are.

Sorry, I can't be more specific, but pick any of half a dozen published protocols, add the anise, the fennel, and the star anise if any, then compare that to the A.absinthium, and you will see what I mean.

If you want to take this further, you must alos factor in the probable weight of extractible essential oils for each herb and the probable % of that that is anethole versus the estimated content of thujone in the A.absinthium.

This is not a very precise methodology as the estimates vary from reference to reference, and in most cases are given as a rather broad range of max to min. Furthermore, the specific amounts actually present in YOUR herbs will depend on a multitude of variables, including origin, drying procedure, age, storage conditions etc.

So it maybe is just as well to reply on relative gross herbal weights and just get a rough idea whether, w/w, the anethole containing herbs are richer in anethole than A.absinthium is in thujone.

Finally when I kicked up that 1000 mg/Kg total oils figure, for sake of argument, I did so with mixed absinthes very much in mind, as I am sure that the total oil content of distilled absinthes is much less than that. I was just going 'worst case' to show that the impact on hydrometer-measured SG would be insignificant anyway.

Sorry to disappoint those waiting for a flame. Nothing incendiary involved.

By Zman7 on Tuesday, October 09, 2001 - 08:22 am: Edit

Actually I did find your answer succinct and understandable to me. IMHO, the readily available Proof/Tralle hydrometers will probablly suffice for most of the absinthe homebrewer types.

By Verawench on Tuesday, October 09, 2001 - 08:15 am: Edit

"Don" indeed.

By Absinthedrinker on Tuesday, October 09, 2001 - 08:02 am: Edit

thujone alert! Don protective masks and flameproof suits immediately!

By Dr_Ordinaire on Tuesday, October 09, 2001 - 07:56 am: Edit

Thanks, Don. I realize now that it wouldn't make any sense to try to measure the difference between the original alcohol and the "herbed" one using a brewhouse hydrometer.

Now, I have a question. I know I'm treading in dangerous territory, feel free to ignore it if there are "marketing" reasons to do it.

You say most of the essential oils are anethole. Why would we get all this anethole and not get a lot of thujone, since thujone has a BP lower than anethole?

By Don_Walsh on Tuesday, October 09, 2001 - 07:34 am: Edit

And when I say that essential oils can be ignored I am talking about absinthe, not any herbal or partly herbal liqueur.

I strongly suspect that no absinthe contains more than 1000 ppm total herbal oils (mostly, anethole from anise, star anise and fennel). This is 0.1%. The specific gravity of these oils is typically somewhere close to 1.0 (again anethole being way out front is 0.988) and so the total max perturbation of the SG of the liquor is 0.1% which is about 20% (one fifth) of the smallest increment of % alcohol by volume that can be read with a good hydrometer.

That's what I mean by negligible.

I have made some assumptions here but I'd have to be off overall by 500% before the answer would change, and even then the error from oils would be a tiny tweak.

Thujone has a sg of: 0.925.

So basically, the oils have a similar density to water, but there isn't enough of them in there to affect the SG significantly.

By Don_Walsh on Tuesday, October 09, 2001 - 07:20 am: Edit

As you might have noticed in the interviews with Sr Segarra, the EU requires liquors as bottled to be accurate to the labelled proof to +/- 0.5 degree C. Believe me, you can't get there with a wide range 'proof' hydrometer, but you can with a good narrow range SG hydrometer (set).

There are probably accurate narrow range sets of proof hydrometers, but I suspect you will not find them at home brew shops.

By Don_Walsh on Tuesday, October 09, 2001 - 07:14 am: Edit

Actually my description is rather confusing.

I don't use proof hydrometers because they aren't so accurate.

I use SG hydrometers for liquids lighter than water (which is 1.000) and I have instruments that go all the way down to absolute ethanol which is .785. It only takes 3 hydrometers of a range of 0.100 g/ml each to cover 1-100% ethanol/water mixtures. And I can read these hydrometers to +/- 0.002 g/ml which is more than good enough to come out to about +/- 0.25 % abv.

The NBS ethanol SG/% charts and temperature correction tables can be had from Tony's site for free. Using them requires a little artistry. Here's the dilemna.

In order to obtain the conversion factor you must read the chart to obtain a number corresponding to the % abv (actually the % water by volume) that you THINK the sample is. And that's the problem, because that's the information you are trying to calculate. So it's a built in error. The ebst you can do to compensate is to know how much the final error will probably be, and correct that at the START of the calculation, which is, scientifically speaking, a bit of a goat-fuck!

By Zman7 on Tuesday, October 09, 2001 - 07:13 am: Edit

"negligent" I meant to type "negligble"
Thanks Don for your succinct explanation.

By Zman7 on Tuesday, October 09, 2001 - 07:08 am: Edit

I asked a similiar question a month or so ago, and it went unanswered. If you are looking to measure the alcohol content of liqour, I would suggest using a "Proof/Tralle" hydrometer. They are readily available at most homebrew stores and work the same way as does a SG measuring hydrometer. As to whether or not the oils have any effect on the reading, I don't know but I think it would be negligent.

By Don_Walsh on Tuesday, October 09, 2001 - 07:01 am: Edit

Well, proof hydrometers are just hydrometers that are calibrated in % ethanol by volume and assuming that the other component is water. Congeners in potable ethanol can be ignored.

Essential oils in absinthe can be ignored. Chlorophyll, or articial color, can be ignored. All of that is because the percentages are too low to make a readable difference.

Sugar can't be ignored if there's enough of it in there, as is likely the case. Certainly the case in liqueurs and pastis.

When you are out to measure sugar content in water, or alcohol/water mixtures, you don't use a proof hydrometer at all, you use a Brix or Bolling hydrometer. These are calibrated in % of sugar (meaning sucrose, specifically.) In fermenting anything, be it wine, beer, or mash for distilling, these are used. A 10 degree Brix/Bolling solution is 10% sucrose. I suppose there is a conversion factor for other sugars like glucose or fructose.

All hydrometers are not created equal, even within same type. For example you can have a wide range hydrometer that covers, in a single instrument, a range of say 30% to 100% ethanol. But it will be rather long and delicate and not very accurate or precise. Or you can have maybe 7 instruments to cover same range, these are each specific to a 10 degree slice of that range. And they will be graduated and readable directly to three decimel places. Not as convenient maybe but more accurate and they are also shorter and easier to handle, and less prone to breakage. Personally I use a set of these sort from 60 degree to 100 degree, plus I have a pair of Brix hydrometers from 0 to 25 Brix and 25 to 50 Brix.

The very best hydrometers are German and the manufactures make a wide variety of specialized ones including "official grade' ones for government regulatory agencies. Of course in Germany the oechscalemeter is used rather than an ordinary hydrometer, but this is just a specialized hydrometer form.

When using a hydrometer, you either need to stabilize temperature to 15 C or you need to have an accurate way to read the temperature of the liquid and then correctly use a modestly complex conversion calculation and chart to correct the reading to the NBS chart of alcohol % vs specific gravity @15 C. Otherwise you will be off -- way off if the liquid is warmer. In practical terms the correction may be as little as a few degrees or as much as 10 degrees (%) or more. It is tedious but worth the effort.

So, the short answer is that UNSWEETENED absinthe will give an accurate proof reading, while absinthe with added sugar will read high, how high depends on how much sugar there is.

The implication for pastis and liqueurs (containing significant sugar) is obvious; the actual alcohol content is LESS than the apparent proof, but the regulatory agencies always go by the apparent proof as far as I know.

There are such things as TDS meters (total dissolvesd solids) but I have never used one, I don't know that these are used in the liquor industry at all, unless it is to QC water before using, and I don't know what interferences might impact the readings.

By Dr_Ordinaire on Tuesday, October 09, 2001 - 06:33 am: Edit

Artemis, I did not intend my answer as a criticism. I was wondering if sugar makes the same big difference in high proof liquids as it does in low proof ones.

I assumed you were only talking about low proof ones.

Aion, what a good idea! I will do it.

BTW, has anybody noticed that mixing water with alcohol (as before distilling) produces an exothermic reaction?

By Aion on Tuesday, October 09, 2001 - 06:21 am: Edit

Dr. O
ever noticed a different measurement of the alcohol before / after maceration (with essential oils solved)? Never checked that myself.
BTW, I never made beer

By Artemis on Tuesday, October 09, 2001 - 06:16 am: Edit

"I was aware of the use of a hydrometer to measure sugar content in low proof liquids (beer). Is there any Hausgemachter who HASN'T started with beer...? I was wondering how much would it affect high proof liquids."

You must have missed this part of my answer:

"Sugar makes all the difference in the world to the specific gravity of water, alcohol, and water/alcohol mixtures (more sugar = higher SG)."

"The sugar part is only a theoretical question"

Forgive me for giving a real world answer to your theoretical question.

By Aion on Tuesday, October 09, 2001 - 06:03 am: Edit

Has anyone information about the SG of essential oils??

By Dr_Ordinaire on Tuesday, October 09, 2001 - 05:48 am: Edit

I was aware of the use of a hydrometer to measure sugar content in low proof liquids (beer). Is there any Hausgemachter who HASN'T started with beer...? I was wondering how much would it affect high proof liquids.

The sugar part is only a theoretical question, since I believe green fairies don't need sugar. Or rather the sugar part should be left to the end consumer...

By Aion on Tuesday, October 09, 2001 - 05:36 am: Edit

Do you have a supersweet creme liquor on hand
(Bailey or such a crap).
Agree with Ian that it should give a wrong measurement with a hydrometer (because of the sugar).

By Artemis on Tuesday, October 09, 2001 - 05:33 am: Edit

Sugar makes all the difference in the world to the specific gravity of water, alcohol, and water/alcohol mixtures (more sugar = higher SG). If it didn't, a hydrometer would be useless for checking the progress of fermentation (i.e., sugar being consumed by yeast, therefore decreasing in quantity). But in fact, that's exactly how such is checked, and why a hydrometer works for the purpose. I can't speak to oils, etc.

By Absinthedrinker on Tuesday, October 09, 2001 - 05:24 am: Edit

I'm sure that Ted or Don could give a definitive answer but I would suggest that sugar will have by far the greatest positive effect on SG (and thus give a lower apparent reading for alcohol) whereas the other components will have a minimal effect in the concentrations in which they are present.

By Dr_Ordinaire on Tuesday, October 09, 2001 - 05:16 am: Edit

To what extent (if any) do "other stuff" in absinthe affect proof hydrometers readings?

As in:

Essential oils

Chlorophyll and vegetable matter


Or to put it another way: would a mixture of pure alcohol and water measure the same way as some absinthe of the same proof?

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