Grading syrup on the border of grades

[ebliese]

We have been using a grader for the first time this year, the Hanna digital grader. I read some threads on here on the grader, it's +/- 4% accuracy, and thoughts on it. In order to minimize variables, we are opting to test the syrup at room temperature. My wife, who has a degree in chemistry, says variations in room temperature (say 72 instead of 77) isn't going to cause that much of a difference when the math is all done with the rounding and such. She did the bottling last night, taking the average of three tests (again, using her chemistry training). She had one test at 74% and two at 75%. So doing all the math it is 74.666666%, rounding it to 75%, or just at the lower level of Golden. Our first batch a few days ago read 74% light transmittance, just missing Golden. Seems a bit odd, perhaps, that our second batch is higher than the first in regards to light transparency but it does fall in the +/- 4% range. Either we have bottled all Amber or all Golden so far.

For those of you who use the Hanna digital grader, what do you do for the grading when it is on the border? Do you also taste the syrup to determine if it is a delicate or rich taste since the grading also has taste (flavor)? Here in Michigan it is not required by law to grade the syrup but we are opting to do this.

[MISugarDaddy]

We have used the Hanna grader for the past three years and we just take whatever the unit reads. We only test the grade of one sample for each batch. It is very important to wipe the calibration and test vials well with the micro fiber cloth to remove any fingerprints as that can affect the reading. We understand your wanting to average out the readings, as we were both auditors before we retired in 2007.

I had read on one thread here once that the reading may change if the sample is left overnight. We have tried that two or three times and found that the reading was the same each time. The nice thing about the Hanna grader, it takes the guess work out of the equation of the grade of the syrup, provided you ignore the +/- 4% accuracy.

Hopefully with the warm up that is forecast this next week, our trees here in Gaylord will begin giving up their sap for us to boil.
Gary

[DrTimPerkins]

If you grade, you should always taste the syrup to be sure it conforms to the class you're assigning it to.

The general rule is to downgrade if it's on or even close to the line. That's because syrup in a container will typically darken over time, especially if packed in plastic (and some types of plastic are more prone to the problem than others). If you are packing in plastic, you should recognize that the syrup will drop in light transmittance pretty quickly (due to oxygen exposure), then level off. https://mapleresearch.org/pub/2006xlcoating-2/ So syrup that close to the line should probably be graded as Amber/Rich rather than Golden/Delicate (assuming the taste is compatible with that classification).

Even syrup packed in glass or metal will tend to darken a little simply due to the small amount of oxygen exposure they get when being put into the container and due to the headspace in the container.

It is not surprising that syrup color will get lighter or darker to some degree from one sap run and boil to the next. If you watch really closely, you'll find that the first syrup you make of the day is a bit darker, and that it'll lighten up as the boil continues. This is because the sap in the pans darkened as it sat there exposed to oxygen, and as you add fresh sap the color will improve. Of course this assumes that the incoming sap is good quality and that your pans aren't nitering up too badly. Much of what happens during the boil will depend on the invert level (caused by microbial degradation) of the incoming sap. If it sat around for a few days...maybe darker. If it was nice fresh sap after a cold spell...might lighten up some. Generally however, over the entire season as things warm up the microbes will eventually win and your invert will go up and your syrup will get darker.

[maple flats]

I always downgraded it if the Hanna Checker was within 2 points of a change over. That's because syrup darkens after bottling.

[ebliese]

Reviving this thread because another question came to mind while working on our order form. What grade do you assign with syrup that has the light transparency of one class but the taste of a different class? For example, our first batch of syrup this year was 74% light transparency but had a delicate taste. Does transparency win out over taste or vice versa?

[SeanD]

Grade it to whatever the "lower" of the two criteria are. If you have Golden colored syrup, but it tastes Amber then it is Amber. If you have Golden tasting syrup, but its color is Amber, then it's Amber.

Flavor can be tricky so get a second opinion and also try it at another time. I drink a lot of coffee and I know that impacts the way I perceive flavors.