Invert Testing

[jrgagne99]

I tested all 19 batches of my syrup last night using a personal diabetes glucose meter. Per the recommendations in the Cornell Confections Guide, I used a 1 in 10 dilution by mass to get the syrup into the measurement range of the glucose meter. (As an aside, Cornell recommends using a digital balance and do 10 grams of syrup to 90 grams of water. A yankee alternative (a.k.a. I'm too cheap to buy a balance :)) is to do the dilution based on volume, not mass. Volume-wise, 1 tsp syrup to 1/4 cup water, works out to 6.5 grams syrup to 59 grams water, which is pretty darn close to the 10:90 ratio.)

Anyway, almost all of my batches tested below 1% invert, including most of my Grade B stock. The highest batch of grade B was 1.5% invert. I'm confident in my measurement technique, having done it for two years now. But I was supprised by the low-invert levels I obtained this year. I think this may be because I consistently used my RO to take my sap to 6% sugar before boiling. I didn't concentrate that high last year.

Just wondering, does anyone else get similar low-invert results for syrup produced with RO, compared to non-RO syrup? In case it matters, almost all of my trees are Red Maples on vacuum.

[happy thoughts]

I tested all 19 batches of my syrup last night using a personal diabetes glucose meter. Per the recommendations in the Cornell Confections Guide, I used a 1 in 10 dilution by mass to get the syrup into the measurement range of the glucose meter. (As an aside, Cornell recommends using a digital balance and do 10 grams of syrup to 90 grams of water. A yankee alternative (a.k.a. I'm too cheap to buy a balance :)) is to do the dilution based on volume, not mass. Volume-wise, 1 tsp syrup to 1/2 cup water, works out to 6.5 grams syrup to 59 grams water, which is pretty darn close to the 10:90 ratio.) ....

I think your water measurement is way off and your dilution is a very weak one which is why your levels are coming out so low. A half cup of water should weigh a LOT more than 59 gms. A TBL of water weighs about 15 gms, 1 fl oz water about 30 gms. A half cup of water (4 fl.oz) would weigh about 120 gms. I think you want 1/4 cup water.

Water needs to be measured in a cup meant for measuring liquids (like a glass pyrex cup) and not ones meant for dry measure for sugar or flour. The syrup would be best measured in the same way. Measuring spoons can vary in accuracy and are also meant for dry measure. That said, measuring by volume instead of weight still isn't going to give you very accurate readings on your glucometer. There's a good reason a gram scale is recommended.

[jrgagne99]

Sorry, that was a typo. I have edited my first post to indicate 1/4 cup water (59 grams), not 1/2 cup. 1 tsp of water is 4.9 grams, so 1 tsp syrup (density ~=1.33) is about 6.5 grams. These are close enough for argument's sake.

My question isn't really on the method, but rather on the findings, and what other people have observed over the years.

For example, does RO'd sap generally result in syrup with low invert levels? In general, are folks seeing low invert levels this year? Do reds usually produce low invert syrup? You get the idea...

[GeneralStark]

I have not had a chance to test any of the syrup I produced this season but I am not surprised by your results. I do typically see low invert (less than 1%) in syrup that I have purchased from producers that ro to high concentrations.

Considering that this was a colder sugaring season, in my location anyway, I suspect that my syrup will have lower invert than last year. One batch of dark syrup produced last year at the every end had invert readings over 8%. That was impressive though not totally surprising.

[jrgagne99]

Bump...

Has anybody done their invert testing this year? Are your invert levels high, low, or just average?