# pH of nectar and sugar syrup



## Redwards (Dec 7, 2013)

I have read and heard that some people lower the pH of the sugar syrup they feed their bees (ie Michael Bush) to more closely mimic the pH of honey by adding vitamin C or viniger. This makes a lot of sense except that syrup simulates nectar not honey so it seems like it would be best to match the pH of nectar. Does anyone know what the pH of nectar is? If not I guess I'll do some testing come spring. Thanks.


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## Chemguy (Nov 26, 2012)

The pH of nectar will vary widely. Baker reported values between 4.2 and 8.5. http://hal.archives-ouvertes.fr/docs/00/89/04/39/PDF/hal-00890439.pdf


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## beemandan (Dec 5, 2005)

This question has arisen before....and yet there are still those who insist on defining sugar syrup as a honey substitute.
The difference today is the link that Chemguy posted. Great find!
I've added ascorbic acid to mine for years but not with any intention of matching nectar/honey pH but simply trying to keep if from growing mold too quickly.
I'm glad you raised the question again Redwards....and thanks again for the link Chemguy.


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## FlowerPlanter (Aug 3, 2011)

How much viniger in needed to reach the 4.2 range?


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## Rader Sidetrack (Nov 30, 2011)

> How much viniger in needed to reach the 4.2 range?

The answer to that varies depending on the characteristics of the _water _that you use to make the syrup. See this earlier thread for info on this issue:

http://www.beesource.com/forums/sho...up&p=992391&highlight=water+strips#post992391


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## Chemguy (Nov 26, 2012)

FlowerPlanter said:


> How much viniger in needed to reach the 4.2 range?


I think vinegar is already pH 2-3 or so. You'd have to dilute it with water about 1:10 or even 1:100 to get up to pH 4. I don't know if white vinegar and apple cider vinegar are different; it is possible that ACV is already at about pH 4-ish. But, white vinegar is 2-3


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## Rader Sidetrack (Nov 30, 2011)

_Chemguy_, I think _FlowerPlanter _is desiring to lower the ph of sugar syrup [by adding vinegar], not raise the ph of vinegar.


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## beemandan (Dec 5, 2005)

Rader Sidetrack said:


> _Chemguy_, I think _FlowerPlanter _is desiring to lower the ph of sugar syrup [by adding vinegar], not raise the ph of vinegar.


I think....ultimately.... the same thing.


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## Redwards (Dec 7, 2013)

Thanks for some good info and comments.


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## Michael Bush (Aug 2, 2002)

Part of the whole equation is the water. Your water can vary, not only in pH, but in how much alkalinity it has. I know pH seems like a measure of alkalinity, but actually it is a measure of free hydrogen ions in solution. Water can have a lot of lime in it which will cause more alkalinity than the pH shows. It acts as a buffer. It can absorb a certain amount of acid without changing the pH much at all. If there a lot less lime, then the same amount of acid will change the pH dramatically. This is why it is difficult to come up with a recipe for how to get your syrup a particular pH. The only real way is to use a tester of some kind. The strips or a digital tester—and experiment. Some testers will differentiate alkalinity from pH.


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## 2ndCharter (Jan 22, 2009)

Michael Bush said:


> Part of the whole equation is the water. Your water can vary, not only in pH, but in how much alkalinity it has. I know pH seems like a measure of alkalinity, but actually it is a measure of free hydrogen ions in solution. Water can have a lot of lime in it which will cause more alkalinity than the pH shows. It acts as a buffer. It can absorb a certain amount of acid without changing the pH much at all. If there a lot less lime, then the same amount of acid will change the pH dramatically. This is why it is difficult to come up with a recipe for how to get your syrup a particular pH. The only real way is to use a tester of some kind. The strips or a digital tester—and experiment. Some testers will differentiate alkalinity from pH.


I know this is an older post but I wanted to add in a bit on what MB said. Water source is very important. As a master gardener, I suggest people have their well water tested every 3 years. If you get a comprehensive test, this can tell you many things about how your specific water conditions can adjust many approaches to how you manage things around your home and business. This can include appliances and systems (think hot water heaters, ice makers, washing machines etc.) to your swimming pool chemistry, your vegetable garden and certainly your bee syrup. 

I for one would never feed treated water to my family or my bees. If you aren't blessed with the good fortune of having a good well, you might want to source your water from another location for the purpose of making syrup. If you have a friend with a fancy aquarium, they might have an RO system (reverse osmosis) and provide you with some very neutral water that would put you in the realm of creating a generic recipe. If all else fails, you could get or produce distilled water.


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## JWChesnut (Jul 31, 2013)

These "pH of syrup" threads, which occur with clock-like regularity, frustrate me no end. 

First, readers must understand, honey has an acid reaction because it is made up of fructose and glucose. Fructose and glucose have hydrogen ions that are loosely bound -- and move in and out of the solution. 

pH measures the relative concentration of those ions as they unbind and rebind to the source molecule or alternatively to anions present in the water in water (which is itself electrically neutral matched (-OH) hydroyl and (H+) hydrogen ions. 

Honey is acid because of its sugars, not because the water in which the sugar is dissovled has been made acid. The two six carbon sugars that make up honey contribute frequent free H+ ions to the water, raising the relative frequency in the short periods before the H+ ions rebind with some negatively charged component. Honeybees take up sucrose syrup and using an enzyme (invertase) in their crop split 12 carbon sucrose into its two constituent 6 carbon sugars. The metabolic cost to the bee of adding invertase to the sugar solution is inconsequential.

There are millions of bees pollinating plants that produce only sucrose nectar (i.e. Avocado's), and these make honey quite well. 

I believe adding ascorbic acid to syrup solutions is good practice -- it prevents spoilage, because it is a useful H+ source and extinguishes anions or OH groups. It catalyzes the "inversion" of sugar -- hydrolysis of the center bridge that joins the two carbon rings together. Every molecule of sucrose that is hydrolyzed extracts one molecule of H20 from the solution --- and nothing makes syrup sweeter faster than removing a molecule of water without going to the energy intensive effort of evaporating it. Bee's invert sugar because it concentrates the remaining solution.

There is no need to "acidify" syrup, per se, however. Bees do this quite well with their very own enzymes, and with remarkable velocity.


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## Michael Bush (Aug 2, 2002)

There are many other acids in honey besides just gluconic:

"Advances in Food and Nutrition Research Volume 62", Edited by Steve Taylor pg 114 (by Jun Wan and Zing X. Li)

"polyfloral and unifloral Italian honey samples contained gluconic acid 92-12 g/kg), pyruvic acid (9-78 mg/kg), malic acid (69-145 mg/kg), citric acid (64-160 mg/kg), succinic acid (12-48 mg/kg), and fumaric acid (0.4-2.6 mg/kg) (Bogdanov et al., 2004)

"Enzymatic methods have been mainly used for the quantification of citric, malic, formic, D- and L-lactic, oxalic and total D-gluconic acids in honeys. It can be also used for the determination of other acids such as acetic, L-ascorbic, and succinic acids (Mato et al., 1998a,b)."


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## JWChesnut (Jul 31, 2013)

Michael,
I don't know what point you are attempting to make.
Pyruvic acid is the end-point of glycolysis -- The breakdown of glucose to form high-energy ATP or NADH -- the basis of metabolism for (virtually) all living things. It is a metabolic byproduct of nature (and releases a H+ in the creation of ATP).

I suggest you review (http://en.wikipedia.org/wiki/Citric_acid_cycle ) or alternatively consult any textbook on the Krebs cycle.


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## Michael Bush (Aug 2, 2002)

The point is that most are not simply from the breakdown of sucrose into glucose and fructose and many have nothing directly to do with sugar. I was just giving a list of acids in honey I didn't filter them down and don't have time to right now. Yes, several, but no where near all, are a result of the breakdown of sugars in one way or another. From multiple sources, here is a more complete list:

succinic (aka butanedioic), fumaric, maleic, malic, citric, lactic, formic (aka methanoic acid), acetic (aka ethanoic acid), oxalic, ascorbic, pyruvic, gluconic, butyric (aka butanoic), tartaric, glucuronic, d-galacturonic, propionic (aka propanoic), quinic, pyroglutamic, salicylic, phosphoric (aka orthophosphoric), valeric (aka pentanoic), valerenic, caproic (aka hexanoic), capric (aka Decanoic), a-ketoglutaric, 2- or 3-phosphoglyceric acid, a- or B glycerophosphate, glucose-6-phophate, pantothenic, nicontinic, folic

Yes, most of the ones with sugars in their name are from the sugars. But there are a lot of acids in honey that have nothing to do with the breakdown of the sugars. They are either coming from the nectar or from the bacteria in the gut of the bee. Most of what comes from the gut of the bee is going to be lactic acid. Formic is one of the primary acids going by amounts.

>alternatively consult any textbook on the Krebs cycle. 

Thanks. I already memorized the Krebs cycle for high school biology, college biology, college A&P and college organic chem...


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## Michael Bush (Aug 2, 2002)

I'm not sure I understand why you think the Krebs cycle is the origin of the acids since that would involve would involve interrupting the Krebs cycle and moving the metabolites from the hemalymph to the stomach. So it seems to me that the source of these is really unknown. 

List of acids that are part of the Krebs cycle and in honey:

succinic (aka butanedioic), 
fumaric, 
malic, 
citric, 
pyruvic, 
alpha-ketoglutaric 

List of acids that are in honey and not part of the Krebs cycle:

maleic (an isomer of fumaric, but not involved directly in the Krebs cycle that I can find), 
lactic (not directly from a complete Kreb cycle, but can result from anaerobic metabolism when the cycle is not completed, but likely is from the LAB in the gut of the bee), 
formic (aka methanoic acid most likely of plant origin), 
acetic (aka ethanoic acid probably a bacterial metabolite, but it is unclear when it occurs),
oxalic (could be created from a metabolite of the Krebs cycle with oxaloacetase, but what is the source of the enzyme?), 
ascorbic (while some animals can break sugar down and create ascorbic acid, I am unaware of any evidence that bees create the necessary enzymes plus this one occurs only in very small amounts), 
gluconic (this occurs naturally in fruit as well as honey, so I would assume it came in the nectar), 
butyric (aka butanoic probably a metabolite of some bacteria, but again, where and at what point in the 
process of making honey), 
tartaric (another one that naturally occurs in fruit and is probably from the nectar), 
glucuronic, 
d-galacturonic, 
propionic (aka propanoic likely a metabolite of some bacteria breaking down sugars, again, unknown if this is in 
the flower or in the hive), 
quinic (most likely of direct plant origin), 
pyroglutamic, 
salicylic (probably of plant origin), 
valeric (aka pentanoic probably of plant origin), 
valerenic (probably of plant origin), 
caproic (aka hexanoic probably a metabolite of a bacteria), 
capric (aka Decanoic probably of plant origin), 
3-phosphoglyceric acid (part of the Calvin cycle used by the plants to make sugar), 
a- or B glycerophospheric (aka Glycerol 3-phosphate probably a metabolite of something, unclear what but likely of animal, therefore bee, origin), 
pantothenic (many possible origins), 
nicontinic (probably plant origin), 
folic (many possible origins


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## JWChesnut (Jul 31, 2013)

Michael
You are changing the terms of the debate. Adding (ascorbic) acid to sucrose sugar syrup is presented on the web and understood in the minds of acolytes as "changing the pH of the syrup to mimic honey". My (rather belabored) point is that fructose-glucose solutions are low pH -- sine qua non --- as that is inherent in the organic compound. The act of collection in the bee's honey crop is what creates the acid reaction, not the doctoring of the compound by adulterants.

The presence of organic acid metabolites in sub-ppm concentrations in natural nectar may or may not affect colony health. I would agree with you (and especially Tim Ives) that natural nectar likely possesses natural flavinoids and other organics that have hive function and regulate gene expression -- this is supported by current publications. 

That's a completely different subject than "dosing" sucrose solutions with a pH lowering compound. Ascorbic acid is a six carbon sugar, where two of the carbons form a short side chain -- hence higher H+ activity and instability than sucrose. Ascorbic can be metabolized in the bee's gut (by symbionts or by the bee itself). 

Bee's take in sucrose, and split its two rings in the center - with an enzyme present in the crop. The bee's do not need some outside agent to do this work for them, they possess the tool themselves. Certainly, pure sucrose diets have been tested and demonstrated as compatible with colony maintenance.

Old world plants favor a nectar that converges on a mix of 50% sucrose - 25% glucose - 25% fructose (and all the other deliberate and accidental metabolites you list in fractional quantities). New world plants are often 100% sucrose. Many tropical plants have significant volume of higher carbon sugars, ketones and carbohydrates, which are entirely indigestible by honey bees (Avocado and Eucalyptus are significant members of that class locally for me).

I hypothesize that the "typical" old world nectar is a coevolved optimum -- the more fructose the "sweeter" an equivalent molar concentration of C in the nectar will taste -- as the fructose consumes water in its creation. Since plants are limited by available C -- the higher the efficiency of the pollination reward (to the plant providing it) the more selective pressure. In hotter and drier climates, H20 is more of limiting factor than C, and the reverse selection occurs.


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## WLC (Feb 7, 2010)

Uh, fellas...

The action of an enzyme present in honey, glucose oxidase, can turn honey acidic under normal conditions. No need to look further.

If I wanted to turn syrup acidic without adding any acid, I would consider adding lactic acid bacteria (LAB) commonly found in probiotics.


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## LizardKing (Feb 12, 2014)

Chemguy said:


> The pH of nectar will vary widely. Baker reported values between 4.2 and 8.5.



That is a WIDE spread of pH!
What is the most common pH of nectar might be a better question or even what is
the pH of nectar that bees prefer.


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## ForrestB (May 26, 2013)

Bump for what I think is some important information/discussion.


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## SeaCucumber (Jun 5, 2014)

If the pH of sugar water tends to be too high, why not open feed diluted vinegar? The bees could add as much acid as they want to their sugar water to get the pH they want.

The internet tells me that the pH range of nectar is wider than that of honey.
Pure 5% vinegar is .83 molar acetic acid and pH 2.4.


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## little_john (Aug 4, 2014)

Why on earth have you dug up a seven-year-old thread about something so irrelevant ? 

As soon as a bee ingests sugar syrup it's chemistry begins to change - so why get hung up on it's initial pH ? Just something to argue about, I suppose ...
LJ


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## HoneywellOperator (8 mo ago)

JWChesnut said:


> These "pH of syrup" threads, which occur with clock-like regularity, frustrate me no end.
> 
> First, readers must understand, honey has an acid reaction because it is made up of fructose and glucose. Fructose and glucose have hydrogen ions that are loosely bound -- and move in and out of the solution.
> 
> ...


I like your post. It’s good to drill into the fine details like you have. Thank you for sharing. 

I use a product called BeeStrong by BeeVital. It is a liquid protein supplement and drops the pH just a little bit. 

My water is really hard, we’ll over 8 before adding sugar. After reading up on this, I looked at it with the BeeStrong. I usually do 25ml per gallon, but since the water is so hard, it took about 40ml to actually get near the 7 mark. 

The stuff is expensive, but I think this is the healthiest way to do it. I just don’t know what they make it from.


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## JWChesnut (Jul 31, 2013)

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