Residual Sugar Testing

Discussion in 'Yeast, Additives & Wine Making Science' started by Ajmassa, Dec 5, 2019.

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  1. Dec 5, 2019 #1

    Ajmassa

    Ajmassa

    Ajmassa

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    I was on Vinmetrica’s website to order som fresh reagents and saw they have a new kit available for residual sugar.

    The description on the site breaks down all the ins and outs of the method used— which is specifically for “reduced” sugar. (With an extra step to test sucrose if desired) They do a great job detailing the test and explaining the science involved. $89 for the reagents and $140 for reagents with labware

    “Specifications:
    -Sensitivity and range: detects down to 0.5 g/L reducing sugar in a 2 mL sample; upper limit is determined by dilution (samples with more than about 25 g/L can be diluted as needed)
    -Accuracy: 0.2 g/L reducing sugar”

    https://vinmetrica.com/product/new-residual-reducing-sugar-assay-kit/ Adjustments.JPG
     
  2. Dec 5, 2019 #2

    mainshipfred

    mainshipfred

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    I don't know how true or accurate this is but I was told a diabetes test kit from a pharmacy can also test residual sugar.
     
  3. Dec 5, 2019 #3

    Ajmassa

    Ajmassa

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    I remember reading something about that as well. I completely forget the name. But I remember reading it was product available at pharmacies but unfortunately it’s no longer sold or possibly discontinued.

    Still waiting on that handheld digital sugar meter to be invented!
    Also the variable capacity carboy!

    However the “laser cutter” hand tool i always envisioned is almost ready! I’ll be handing over my money when they get them powerful enough to at least cut Sheetrock. But making progress. Check it out https://torchexpro.com/pages/tactilax
     
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  4. Dec 5, 2019 #4

    stickman

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  5. Dec 6, 2019 #5

    sour_grapes

    sour_grapes

    sour_grapes

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    I didn't realize that those roadside signs that say "CASH for diabetic test strips" were posted by winemakers! :D

    [​IMG]
     
    Last edited: Dec 6, 2019
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  6. Dec 6, 2019 #6

    Ajmassa

    Ajmassa

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    Nailed it! Thanks. Yeah there’s some old threads on here discussing it I remember now. Which is where I initially became aware.

    @sour_grapes —— that’s real? I’v never seen those signs in my life. Seems incredibly random lol
    “Cash for gold”, “we buy junk house”, “cash4junk”, “cash your junked cars” —sure.
    “Cash for unused diabetes testing supplies” —that’s a new one for me for sure!
     
  7. Dec 6, 2019 #7

    sour_grapes

    sour_grapes

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    Sadly, it is very real. I see these signs frequently -- moreso in rougher parts of town. For a long time, I ALSO thought this ploy seemed weird and random, but I eventually caught on (with some help from the googler). Evidently, the gig is that some diabetics get or buy strips heavily subsidized by their insurance, so they pay far less than retail. They then hold back on using all of them, and then sell the extras to 3rd party vendors. The vendors in turn sell them to diabetics who lack insurance altogether; the vendors sell them at less than retail, but (obviously) above what they pay for them.

    All of this is legal. Just a damn sad state of affairs.
     
    Last edited: Dec 6, 2019
  8. Dec 6, 2019 #8

    sour_grapes

    sour_grapes

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    Here you are, my friend. Not exactly Bustleton, but you could walk from there in a coupla hours if you had to:

    test strips.jpeg
     
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  9. Dec 6, 2019 #9

    1d10t

    1d10t

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    Location:
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    Decades ago there was a little shack of a store front in WVA that had a sign out front announcing they did PAP tests.
     
  10. Dec 6, 2019 #10

    Ajmassa

    Ajmassa

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    Hmmm. You tracking me?

    Adjustments.JPG
     
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  11. Dec 6, 2019 #11

    sour_grapes

    sour_grapes

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    Oh my goodness! That was a bit uncanny!
     
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  12. Dec 6, 2019 #12

    Ajmassa

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    I opened the post and happened to be right there! (Which is often) Lots of work at Temple’s Episcopal hospital at Kens. & Lehigh over the years, every holiday picking up a pound cake from Stock’s bakery, and just yesterday looked at a new job at one of those old monstrous Church’s right there on Allegheny, Nativity BVM.

    I should take more notice of my surroundings! But To my credit—there’s plenty of sights and experiences in the hood distracting me !
     
    Last edited: Dec 6, 2019
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  13. Dec 6, 2019 #13

    sour_grapes

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    My sister just LOVES Stock's pound cakes. I don't have much of a sweet tooth, so I am indifferent.

    Be safe!
     
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  14. Dec 7, 2019 #14

    jgmillr1

    jgmillr1

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    Getting back to the original topic here...

    As we all know, the issue with using either SG or refraction to determine the residual sugar is the alcohol confounding the measurement. What about getting rid of the alcohol? Just thinking here...

    So, what if you took a 100ml sample of wine, boiled it to evaporate the alcohol, cooled and reconstituted it back to 100ml, and then finally took the SG or refractometer brix measurement? Seems like that might work, but haven't tried it myself yet.

    Of course that still leaves behind the various dissolved acids which will definitely offset the measurement. So this technique may be most accurate for sweet wines and less reliable on wines under 10g/L residual sugar.
     

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