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bernardsmith
11-03-2013, 09:37 AM
If I add 6 pints of water to 2 pints of honey and mix thoroughly is the resulting volume precisely 1 gallon or is it significantly less? In other words, does honey behave at all like say dextrose or sucrose or salt when if you take a volume of those items and add that volume to water the spaces in the molecules of water take up some of the molecules of the additives?

Please note, that I am not asking if I add a known volume(X) of honey to a known volume (Y) of water the total will be close enough to X+Y for our purposes. I am asking if the volume will be X+Y or less.

fatbloke
11-03-2013, 10:03 AM
If I add 6 pints of water to 2 pints of honey and mix thoroughly is the resulting volume precisely 1 gallon or is it significantly less? In other words, does honey behave at all like say dextrose or sucrose or salt when if you take a volume of those items and add that volume to water the spaces in the molecules of water take up some of the molecules of the additives?

Please note, that I am not asking if I add a known volume(X) of honey to a known volume (Y) of water the total will be close enough to X+Y for our purposes. I am asking if the volume will be X+Y or less.
As far as I'm aware it's the same. The water content of the honey making the sugars etc act in a "water-like" way. Besides, you say 2 "pints" of honey, rather than 2lb so by using volumetric measures like that, the volume should be right.

It gets a bit weird when using different measures i.e. how much a pound of honey actually takes up as a volume might cause a bit of mis-measurement.

Personally, I just use weight for the honey, then volume for the water, then test. If it gives too high a gravity for what I'm looking for, I'll add a bit more water, then test again.

Any excess must goes in a bottle in the fridge as it's always handy for topping up or back sweetening........

Riverat
11-03-2013, 08:10 PM
You should wind up with slightly less than X+Y but at those volumes not much, that is, probably close enough. Honey should only be 20% water so at some point (larger volumes) it will become noticeable, thus many of us mix water and honey to a minimum final volume and a specific target gravity and go from there.

Medsen Fey
11-03-2013, 08:18 PM
The total volume will be a bit less than X+Y.

fatbloke
11-03-2013, 09:52 PM
You should wind up with slightly less than X+Y but at those volumes not much, that is, probably close enough. Honey should only be 20% water so at some point (larger volumes) it will become noticeable, thus many of us mix water and honey to a minimum final volume and a specific target gravity and go from there.


The total volume will be a bit less than X+Y.
Ok, now you've got me confused.......

If you measure out 2 dis-similar liquids in volumetric measures i.e. 2 "pints" of honey and 6 pints of water, why is it gonna come out less than a gallon.

As bernardsmith points out, when you're mixing 2 "pints" of dextrose or sugar and 6 pints of water, it will come out slightly less.

Surely that's because when dealing with solids like sugar or dextrose, measured as volumes and not weight, there is always gonna be some element of air involved, so once the solids (powder types in this case) have dissolved, then the resulting liquid level will be lower as all the air that was between the grains would then take up the space between the top of the liquid level and the 8 pint/gallon marker.

Whereas, he's on about 2 pints of honey, where the sugars are already dissolved. So having measured the honey by volume, along with the volume of water i.e. the 6 pints, when mixed, they will still be 8 pints volume.

So WHY is it gonna be any less, however small amount less, but less ? 2 volumetric measures of liquids like this don't get any smaller ?

Please help in this moment of confusion ?

joemirando
11-03-2013, 10:19 PM
Ok, now you've got me confused.......

If you measure out 2 dis-similar liquids in volumetric measures i.e. 2 "pints" of honey and 6 pints of water, why is it gonna come out less than a gallon.

As bernardsmith points out, when you're mixing 2 "pints" of dextrose or sugar and 6 pints of water, it will come out slightly less.

Surely that's because when dealing with solids like sugar or dextrose, measured as volumes and not weight, there is always gonna be some element of air involved, so once the solids (powder types in this case) have dissolved, then the resulting liquid level will be lower as all the air that was between the grains would then take up the space between the top of the liquid level and the 8 pint/gallon marker.

Whereas, he's on about 2 pints of honey, where the sugars are already dissolved. So having measured the honey by volume, along with the volume of water i.e. the 6 pints, when mixed, they will still be 8 pints volume.

So WHY is it gonna be any less, however small amount less, but less ? 2 volumetric measures of liquids like this don't get any smaller ?

Please help in this moment of confusion ?

It may be for a different reason, but does this not happen, albeit to a miniscule extent, with ethanol and water? Granted, the discrepancy is quite small (IIRC, 1 liter water + 1 liter ethanol = 1.9x liters).

With honey, I suppose it could be possible that the sugars have not reached saturation and could take 'absorb' a little bit more water. Now, as far as how much and under what conditions, I have no idea.

Joe

Medsen Fey
11-04-2013, 09:16 AM
Ok, now you've got me confused.......

If you measure out 2 dis-similar liquids in volumetric measures i.e. 2 "pints" of honey and 6 pints of water, why is it gonna come out less than a gallon.


The classic example is ethanol and water. If you mix 500cc of each you end up with less than 1000cc of total volume. Essentially, the ethanol and water molecules can jam in together and fill up the spaces between molecules. The effect is pressure and temperature dependent.

The effect varies depending on what substances are mixed. Salt is another classic example, where the volumes come out to be lower when dissolved. I think smaller molecules probably show more of this phenomenon. You see it to a much lesser degree with sugars, but it is still there. Since honey is a supersaturated sugar solution the effect will still be present, though even less.

See this site for more info
http://www.madsci.org/posts/archives/1998-08/903328122.Ch.r.html

Also see here
http://www.newton.dep.anl.gov/askasci/chem03/chem03838.htm

And here is a classic demonstration with salt you can do at home and amaze your friends and family.
http://www.nuffieldfoundation.org/practical-physics/volume-change-dissolving-salt-water

So when it comes to brewing or making mead, this effect is so teeny-tiny that it makes no difference. In fact, if you are aiming for a specific volume, like the amount to fill a carboy, the amount of error in the volume of the container is a much bigger concern.

However the question asked was "does the total exactly equal X+Y" and the answer is no, but the difference is so small you'll need special equipment to measure it.

fatbloke
11-04-2013, 10:05 AM
TVM Medsen, that all makes sense i.e. that while the amount of discrepancy is small, it's still there.

I'd guess that the difference, being on the molecular level, wouldn't even matter on a massive industrial level, yet as you correctly point out, it's still there.......

It begs the question why Bernard is bothering himself with such question. If it's a known effect, and for all intent and purposes, isn't measurable (or prohibitively complex and/or expensive) in a home brew environment........

Each to his own I suppose.....

Chevette Girl
11-04-2013, 09:46 PM
"2 dissimilar liquids" will not behave like this unless one dissolves into the other. Mix X volume of oil with Y volume of water and you get X+Y total, but when you do it with something that dissolves, like salt, sugar or ethanol in a solvent like water, it's the dissolution that causes things to be able to occupy some of the same space. SCIENCE!!

McJeff
11-04-2013, 10:18 PM
Too much math

bernardsmith
11-04-2013, 10:18 PM
TVM Medsen, that all makes sense i.e. that while the amount of discrepancy is small, it's still there.

I'd guess that the difference, being on the molecular level, wouldn't even matter on a massive industrial level, yet as you correctly point out, it's still there.......

It begs the question why Bernard is bothering himself with such question. If it's a known effect, and for all intent and purposes, isn't measurable (or prohibitively complex and/or expensive) in a home brew environment........

Each to his own I suppose.....

Sorry Fatbloke, Those who take for granted what they might interrogate and explore are those who beg questions. Me? I take nothing for granted and interrogate anything and everything that purports to be common sense knowledge. If you tell me that 2 pts of honey added to 6 pints of water result in 1 gallon and if I find that it doesn't then I want to know why it doesn't. The begged question is the question that you shrug off as uninteresting because the answer is no bloody use to you. Me ? I am curious about the answer so it's of use to me...

anir dendroica
11-05-2013, 02:35 AM
Mass is always conserved, but there is no such law for volume.

If you mix a gallon of honey (SG ~1.5) with a gallon of water (SG = 1.0), you could end up with two gallons at SG 1.25. Or you could end up with 1.92 gallons at SG 1.3. Both are physically possible. Experiments show that the volume is slightly less than expected.

Similarly if you dissolve salt in water the volume will not increase by much but the density will increase, so all of the mass is still accounted for.

Riverat
11-05-2013, 12:54 PM
I remember a story about a teacher and a glass jar, he filled it with golf balls and asked the class if the jar was full to which they agreed it was, he then jiggled jelly beans into the spaces and reiterated the question, now they were not so sure, then he added fine sand and it settled into the remaining open spaces and many announced the jar as full.....he then emptied his thermos of coffee into it....still think it's full he asked?
Not a bad analogy of what we are discussing here without getting into the whole miscible, ionic solutes, molecular spacing and so forth