formula for % sugar to gal of syrup

[marc b]

what is the formula for % sugar to how much syrup it would make. someone told me that u divide the % of sugar in the sap by 86 and that is your ratio of gallons of sap to gallons of syrup made ?

[spencer11]

yes, divide the suger % by 86 and thats how many gallons of sap it tapes to make a gallon of syrup.

spencer

[maple man]

rule of 86 % divided by 86 minus 1 86 divided by 2% sap =43 -1 =42 you have 42 gallons of water to make one gallon of syurp

[wiam]

rule of 86 % divided by 86 minus 1 86 divided by 2% sap =43 -1 =42 you have 42 gallons of water to make one gallon of syurp

Never heard of the minus 1 thing.

[spencer11]

i think what he means is thats how many gallons of water you have to boil off to get 1 gallon of syrup. i didnt understand it at first either.

spencer

[Maplehobbyist]

Where does the 86 come from? I'm having a hard time figuring out a relationship between that number and the amount of sugar in a gallon of syrup.

[spencer11]

i dont know where it comes from. i just know thats what we are suppose to use.

spencer

[wcproctor]

How much sap to make a
Gallon of syrup

3% will take 28 gallons to make 1 gallon

2% will take 43 gallons to make 1 gallon

1.5% will take 57 gallons to make 1 gallon

1% will take 86 gallons to make 1 gallon

[happy thoughts]

It's a recognized constant. I couldn't explain where pi comes from either but we know it works:) It probably has something to do with the weight/volume of water vs that of sugar in a given measure and that may be what's messing up the logic for you.

[DrTimPerkins]

Where does the 86 come from?

It comes from the empirical rule developed by C.H. Jones of the University of Vermont (Vermont Agricultural Experiment Station) called the "Jones Rule of 86" which was published in a long treatise (with J.L. Bradlee as co-author), "The Carbohydrate Contents of the Maple Tree" in 1933. We still refer to that paper occasionally even now...it is a very important contribution to maple science.

There is a section in the North American Maple Producers Manual which explains the "Jones Rule of 86" in some detail.

[Maplehobbyist]

I guess what I'm having trouble wrapping my brain around is, if we follow the examples listed--1% sugar content = 86 gal of sap, 2% = 43 gal of sap, 3% = 28 gal of sap, etc--then if we had 1 gallon of sap at 86% sugar, then that would be a gallon of syrup? I thought sap was syrup at 66% sugar...I'm clearly missing something.

[happy thoughts]

I guess what I'm having trouble wrapping my brain around is, if we follow the examples listed--1% sugar content = 86 gal of sap, 2% = 43 gal of sap, 3% = 28 gal of sap, etc--then if we had 1 gallon of sap at 86% sugar, then that would be a gallon of syrup? I thought sap was syrup at 66% sugar...I'm clearly missing something.

what you're missing is what I mentioned earlier- the percent is based on the weight of the sugar and water that make up the sap. If you had a gallon of sap that was 86% sugar, 86% of it by weight would be sugar and 14% by weight would be water.

[Sugarmaker]

86% sugar content would be way over density. Several things her to consider. Syrup at or near 67% brix will not crystallize in the container.
Syrup below 67% brix may start to mold quicker.
So the ration of water and sugar in solution is optimal at 67% sugar. Syrup at that density will weight about 11 lb per gallon.
Regards,
Chris

[Maplehobbyist]

...86% sugar content would be way over density...

And that is precisely what I don't understand about the formula. Why would it be true for 86 gallons at 1% sugar content but not for a theoretical gallon at 86% sugar content?

[happy thoughts]

And that is precisely what I don't understand about the formula. Why would it be true for 86 gallons at 1% sugar content but not for a theoretical gallon at 86% sugar content?

OK I see where you're going with this and the answer is probably what sugarmaker said. 86% is way over density and wouldn't be a real reading anyone would ever see. The formula was probably derived from a lot of actual brix readings for sap. It's just a guideline and not meant to be precise. Higher sugar densities probably increasingly throw off the guestimate as the concentration of sugar gets higher????

Darn! Now you got me wondering. I'm going to have to find that guy Jones lol:)

[happy thoughts]

OK I found this in an old online copy of the maple syrup manual. I think this helps explain the confusion.

http://www.archive.org/details/maplesirupproduc00willrich

"Since the solids concentration of sap is comparatively low, its Brix value and percentage of solids (weight-volume) are essentially the same."

So if I understand this right, then higher concentrations of sugar have a weight that essentially differs from the brix reading. The formula would not hold true then (.... in the 86% example).

[Maplehobbyist]

Thanks for posting that, happy thoughts. I searched online yesterday for the 'rule of 86' but didn't really find anything that explained it, just examples of people using it.