Specific Gravity of Fruit

Discussion in 'General Wine Making Forum' started by Chris Pittock, Feb 8, 2019.

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  1. Feb 8, 2019 #1

    Chris Pittock

    Chris Pittock

    Chris Pittock

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    This is a technique type question and something that I have been wondering about for a while.

    When I make wines from juices, tinned fruit or packaged fruit, the sugar content is listed on the labels so I can work out how much sugar to add to get the results I want. If I am using just juices I can take a hydrometer reading to check I have the S.G. I want.

    However, if I use picked or loose fruit I don't know how much sugar is contained so I have to guess. If I add this fruit to juices and/or water in a fermentation bin, using a hydrometer right at the start won't tell me how much sugar is still in the fruit as it won't have been released. Therefore I risk adding too much or too little sugar. In fact last year I did add too much sugar and ended up with an extremely sweet wine. I ended up blending with another very dry wine, which happily worked very well.

    Is there a way I can do better than just guess the sugar content of a given fruit?
     
  2. Feb 8, 2019 #2

    dralarms

    dralarms

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    Freeze the fruit and thaw or steam juice the fruit. Wine makers take a sampling by taking a few grapes and squeezing the juice out and measuring the sugar content using a refractometer
     
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  3. Feb 8, 2019 #3

    Stressbaby

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  4. Feb 8, 2019 #4

    mainshipfred

    mainshipfred

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    I'd buy the refractormeter, they are really cheap and will make the testing much easier.
     
  5. Feb 8, 2019 #5

    Rice_Guy

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    There are tables of what is typical / average. , , In the US I could pull out a hard copy of “USDA hand book 8” or for less extensive info go to a nutrition textbook / CD nutrient calculator program / weight watchers web site. The EU should have similar available.
    Crops will vary and generally speaking be higher sugar the longer they are on the plant. I will juice at least 50 ml of any ingredient I debate using, to find an actual value.
    For tinned/ packaged foods the nutrient info should equal handbook 8.
     
  6. Feb 8, 2019 #6

    salcoco

    salcoco

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  7. Feb 8, 2019 #7

    salcoco

    salcoco

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  8. Feb 8, 2019 #8

    Chris Pittock

    Chris Pittock

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    Thanks guys, that's been very helpful. Are those refractormeters I've seen on eBay any good and easy to use?
     
  9. Feb 8, 2019 #9

    mainshipfred

    mainshipfred

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    I'm sure some are better then others but mine was $25.00 I think and works just fine.
     
  10. Feb 8, 2019 #10

    salcoco

    salcoco

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    there are digital and analog versions . the should be temperature compensating. Amazon should also have some. they are internally used to measure the sugar of fruits, grape and a wine must. they can also be used to monitor the fermentation although alcohol will cause a distortion of the reading. there are spread sheets on the internet that can be used to calculate the real specific gravity. since they only need a drop of fluid to make a measurement they are a lot more handy than a hydrometer.
     

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