measuring sap %

[jmayerl]

Which is more accurate to measure with a sap refractometer that measures 0-18 brix or a sap hydrometer. They both cost under 35 bucks so I would just like to get whichever is most acurate and also can read down to the nearest tenth if possible.

[DrTimPerkins]

Which is more accurate to measure with a sap refractometer that measures 0-18 brix or a sap hydrometer. They both cost under 35 bucks so I would just like to get whichever is most acurate and also can read down to the nearest tenth if possible.

Assuming they are both calibrated properly, they can both be fairly precise (able to read to the nearest tenth), but a sap hydrometer is probably a bit more accurate.

What are you planning to use it for? If just for sap from a tank in the sugarhouse, then either will work. If you want to also use it to test sap sugar from individual trees, you probably want a refractometer (needs only a few drops).

[jmayerl]

I'm only looking to measure sap from the tank. Thanks Dr., also I just found the old thread about this.

[Wardner in Tewksbury]

I've been looking at refractometers too. eBay has a 0 to 10% optical unit. It appears to be made by the same company that makes the 0 to 18% unit but is more money.

Speaking of more money, the sellers of maple equipment want around $90 for the same thing as an eBay unit selling for $23. Is there any good reason to buy from the maple guys?

Now, I have a question. Are the digital refracs any good? They are capable of 0 to 85%. Could or would a syrup maker use one of these for both sap, syrup, and candy? Would the temperature of the hot syrup be too much?

I saw a U-Tube video where an experienced tapper was taking readings at the tree with a digital. He was amazed that some readings were coming back at 8%. Is that an error or is it possible?

Will there be a significant difference from sap taken at breast height or from a broken twig off a low hanging branch on the same side of the tree?

[DrTimPerkins]

Make sure the refractometer you buy is made to measure sugar. Some measure other things. You want one that has a Brix scale. Should be temperature compensated. Another thing is how finely divided the scale is.

Digital units work well. Some are better than others. You need a battery though. Some will take hot syrup, some won't (ask).

Yes, trees can range a lot in sugar content, up to about 10-11%. The particular trees in the video were in an orchard planted for high sugar content.

There are LOTS of ways to make errors measuring sap sugar. There are good publications describing how to do it properly. Do a search on this site.

[green4310]

http://www.hannainst.com/usa/prods2.cfm?id=039001&ProdCode=HI%2096801

I got this one last year. I found that it worked very well for syrup that is not changing temperature rapidly as in hot sampling from evaporator. I get a teaspoon full sample of hot and let it stabilize for a minute and then measure. It was right with the hydrometer and much easier and less messy. Certainly close enough to bulk store for later bottling. I tried it to check raw sap and found likwise accuracy compared to sap hydro. I would not even try to read very low sugar values from say permeate, even though it is marketed as 0-80 Brix. Incidentaly, I have tried hydrometer red hot line, and refractometers, and boiling point plus 7.3, and this way, for me has been the most reliable. Who knows maybe another method will pop up this year. Hope this makes sense somehow.

[DrTimPerkins]

[I would not even try to read very low sugar values from say permeate, even though it is marketed as 0-80 Brix.

Good point. At the extremes, these units can be less reliable. Just a very small miscalibration can make a big difference.

We've used several types of optical and digital refractometers. The one I currently use myself, and like a lot, is the Misco eMaple http://www.misco.com/products/PA202X-306-307.html You can get a nice rubber armored bump case for it which provides a lot of protection.