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### Author Topic: Sugar as a moisture absorbant  (Read 2676 times)

#### boca

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##### Sugar as a moisture absorbant
« on: September 16, 2011, 09:19:27 AM »
I have a question to those who recommend normal white sugar to be put in the hive as a moisture absorbant.

Do you have literature references or own experiments to answer these questions?

1. How much water can be absorbed by sugar in the moist environment of a wintering hive? (previously stored in a dry room, lets say 50% rel. humidity and 20C/68F)
2. How much water is produced by the bees? (assuming they eat only 5 kg of sugar during winter)
3. Based on the previous two data, how much sugar we have to put in the hive to prevent condensation?

#### kathyp

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##### Re: Sugar as a moisture absorbant
« Reply #1 on: September 16, 2011, 10:29:35 AM »
for me, the moisture absorption is a side benefit to having the sugar on as emergency feed.  don't know how much is absorbed, but i know it goes on dry and then it gets wet  :evil:
One could not learn history from architecture any more than one could learn it from books. Statues, inscriptions, memorial stones, the names of streets ? anything that might throw light upon the past had been systematically altered. (1.8.85)

George Orwell  "1984"

#### Michael Bush

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##### Re: Sugar as a moisture absorbant
« Reply #2 on: September 16, 2011, 10:38:13 AM »
I put it on for food.  I put a top entrance on to let out the moisture.  It does absorb some of the moisture and that's good as it makes it more palatable.

The amount of water could be calculated, but I'm not awake enough to do it right now.  Basically you'd need to calculate the number of moles of sugar in a pound (based on atomic weight of sucrose) and how many moles of water would be produced and then use the atomic weight of the water to calculate that back to pints of water (or better yet it would be much easier to calculate in metric and then covert back).

But some of the moisture is always going to escape, and more if you have a top entrance or vent of some kind.  There has to always be enough air exchange to provide the bees with oxygen and that exchange will lose moisture as well.

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#### CapnChkn

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##### Re: Sugar as a moisture absorbant
« Reply #3 on: September 17, 2011, 05:00:04 AM »
I tried to figure out how many moles would be in a pound of sugar and water, but they wouldn't hold still long enough.
"Thinking is like sin, them that doesn't is scairt of it, and them that does gets to liking it so much they can't quit!"  -Josh Billings.

#### Michael Bush

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##### Re: Sugar as a moisture absorbant
« Reply #4 on: September 17, 2011, 01:10:21 PM »
>I tried to figure out how many moles would be in a pound of sugar and water, but they wouldn't hold still long enough.

Yes, I know how that is...
My website:  bushfarms.com/bees.htm en espanol: bushfarms.com/es_bees.htm  auf deutsche: bushfarms.com/de_bees.htm
My book:  ThePracticalBeekeeper.com
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"Everything works if you let it."--James "Big Boy" Medlin

#### boca

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##### Re: Sugar as a moisture absorbant
« Reply #5 on: September 17, 2011, 04:01:11 PM »
There are numerous statements on this forum and elsewhere on the net claiming that dry sugar contributes to prevent condensation within the hive during winter, but failing to specify how much it does.

Not many people have replied to my question, those who did could not answer. So I'll try.

1. How much water can be absorbed by sugar in the moist environment of a wintering hive? (previously stored in a dry room, lets say 50% rel. humidity and 20C/68F)

Dry crystallized sugar contains moisture in two forms:
- Included water in the crystals: 0.05 - 0.07 %. It is not affected by the humidity of the surrounding air, so it is irrelevant in this context.
- Surface water: 0.03 - 0.05 % in form of saturated syrup on the surface of the crystals. This moisture is affected by the relative humidity of the surrounding air (hygroscopic).
The maximum amount of the surface water depend on the surface of the crystals, which in practice means the fineness of the grains.
Table sugar typically has a "Mean aperture (MA)" of 500 µm with a "Coefficient of Variation (CV)" between 28 and 40.
Sugar with this fineness can absorb up to 1% of moisture.
In fact during the production of sugar the crystals are separated from the syrup by centrifugation. The resulting "wet sugar" contains less than 1 % of moisture before drying.

This means that 1Kg of sugar can absorb up to 10 g of water.

2. How much water is produced by the bees? (assuming they eat only 5 kg of sugar during winter)
The energy is obtained by the bees from sugar with the process called aerobic respiration. The process can be simplified and represent with the following reaction:
C6H12O6 + 6 O2  → 6 CO2 + 6 H2O
(sugar + oxygen → carbon dioxide + water)
2880 kJ of energy released during the reaction per mole of C6H12O6.

The molecular weights are:
C: 12.0108 g/mol
H: 1.0079 g/mol
O: 15.9994 g/mol

C6H12O6: 180.1566 g/mol
O2: 31.9989 g/mol
CO2: 44.0096 g/mol
H2O: 18.0153 g/mol

Therefore:

180 g sugar + 192 g oxygen  →  264 g carbon dioxide + 108 g water

The aerobic respiration of 1 kg of sugar produces 0.6 kg of water.
(On top of that bees exhale the water content of honey)

3. Based on the previous two data, how much sugar we have to put in the hive to prevent condensation?
The metabolism of 5 kg of sugar produces 3 kg of water. 1 kg of sugar can absorb 10 g of water. Therefore we need 300 kg of dry sugar to prevent condensation.

Conclusion:
Those who believe that dry sugar absorbs the excess moisture in the hive are right. However, if we quantify the dry sugar necessary to achieve that objective, we realise the amount needed is impractical. The amount of dry sugar put typically in the hive have not enough capacity to reduce the moisture significantly.

#### kathyp

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##### Re: Sugar as a moisture absorbant
« Reply #6 on: September 17, 2011, 05:04:34 PM »
ok.  well, now my brain is fried  :evil:  in your calculations did you factor in how much moisture is lost from the sugar on dry days when moisture would evaporate not only from the sugar, but from the hive itself?   :-D

One could not learn history from architecture any more than one could learn it from books. Statues, inscriptions, memorial stones, the names of streets ? anything that might throw light upon the past had been systematically altered. (1.8.85)

George Orwell  "1984"

#### Poppi

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##### Re: Sugar as a moisture absorbant
« Reply #7 on: September 17, 2011, 06:19:48 PM »
LOL kathyp...     as if we don't have enough to deal with already...  vent the hive like Michael says...  I know...  hopefully someone will invent a central heating and air system...

#### BlueBee

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##### Re: Sugar as a moisture absorbant
« Reply #8 on: September 17, 2011, 10:20:26 PM »
Wow, somebody paid attention in Chemistry class!  Good to see.

So Boca, are you using a top vent to get rid of that moisture?

I have no knowledge in sugar processing, but I am a little surprised that wet sugar is only 1% moisture.  Learn something new everyday.

Mass of Sugar + O2 is just a smidgen greater than the mass of the CO2 + H2O.  That’s so we get to bring up E=mc^2.  That small smidgen of mass deficit times the speed of light squared gets our bees that 2880 kJ/mole of released energy.  We gotta get Einstein involved in here somewhere :)

Isn’t bee keeping fun :)
« Last Edit: September 18, 2011, 01:14:58 AM by BlueBee »

#### windfall

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##### Re: Sugar as a moisture absorbant
« Reply #9 on: September 18, 2011, 12:02:42 AM »
Boca your calculations are correct but you assume that all moisture is retained in hive to be absorbed. Obviously some air exchange is necessary for the hive. And with that some moisture will vent also.
All the sugar has to do (and I have no idea if it does it) is absorb the extra moisture on those days/periods when the dew point is reached inside the hive causing condensation.
As Kathy points out there may be other days and conditions that cause the release of water from the sugar so that it is ready to help again next time.

#### Michael Bush

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##### Re: Sugar as a moisture absorbant
« Reply #10 on: September 18, 2011, 08:28:56 AM »
As windfall, and I, pointed out you HAVE to have some air exchange for the bees to breath, so it is not a closed system.  Second there is a certain amount of flywheel effect where it both absorbs and under other conditions gives off moisture.  But as I said, my main concern is bringing the hive up to weight.  I have no real expectations of any significant amount of absorption.

If you look at those little silca gel packs they add to everything from beef jerky to guitars, in theory they can't absorb that much moisture, but again, I think they act more as a flywheel, stabilizing the humidity, more than changing it and again, preventing condensation in the case of guitars or vitamins or computer monitors.
My website:  bushfarms.com/bees.htm en espanol: bushfarms.com/es_bees.htm  auf deutsche: bushfarms.com/de_bees.htm
My book:  ThePracticalBeekeeper.com
-------------------
"Everything works if you let it."--James "Big Boy" Medlin

#### BBees

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##### Re: Sugar as a moisture absorbant
« Reply #11 on: September 18, 2011, 09:09:46 AM »
Surprised no one's reported using disposable diapers to resolve moisture issues! Could have a lot of fun with that thread! LOL
Choose a job you love, and you will never have to work a day in your life. Confusius

#### kathyp

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##### Re: Sugar as a moisture absorbant
« Reply #12 on: September 18, 2011, 01:39:32 PM »
probably because most of us are to old to have those things on our mind, unless we are changing grandkids :-).

it's a thought.  wonder if they add any insulating value??
One could not learn history from architecture any more than one could learn it from books. Statues, inscriptions, memorial stones, the names of streets ? anything that might throw light upon the past had been systematically altered. (1.8.85)

George Orwell  "1984"

#### boca

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##### Re: Sugar as a moisture absorbant
« Reply #13 on: September 24, 2011, 07:36:26 AM »
So Boca, are you using a top vent to get rid of that moisture?
I'm not going to get in the top went discussion.

Mass of Sugar + O2 is just a smidgen greater than the mass of the CO2 + H2O.  That’s so we get to bring up E=mc^2.  That small smidgen of mass deficit times the speed of light squared gets our bees that 2880 kJ/mole of released energy.  We gotta get Einstein involved in here somewhere :)
No. Eistein's theory is obsolete in Europe.

Isn’t bee keeping fun :)
It must be fun watching me when I run while the bees are chasing me.

#### BlueBee

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##### Re: Sugar as a moisture absorbant
« Reply #14 on: September 24, 2011, 12:04:27 PM »
I read about that Einstein defying experiment the other day.  Sounds like our Republicans want to call him in front of the Senate for a grilling :-D  How dare he be wrong.

This would be one of the biggest surprises in 100 years if true.  It will be exciting to see if the experiment can be replicated.