Residual Sugar Testing

[mendozer]

I've never tested in years prior but I'm trying to be more precise as time goes on. All my materials show people using Clinitest tablets and using a color chart. But Bayer discontinued these and it seems urine analysis home kits are going to dip sticks vs tablets. I can't fine Accuvin Residual sugar anymore online either or near me.

how are people testing this now?

 

[Rice_Guy]

most of us don’t test for glucose, which is one of the residual sugars

a technical answer is that actual residual sugar is a lab test for reducing sugars, , humm think it was a permanganate reaction

 

[winemaker81]

I use the SG (before and after backsweetening) to roughly determine the RS.

 

[Swedeman]

I believe that Urine test strips only tests for glucose and not fructose. Accuvin Residual sugar test tested for both glucose and fructose. Why would you like to test for this?

a technical answer is that actual residual sugar is a lab test for reducing sugars, , humm think it was a permanganate reaction

I believe the preferred lab method these days is an enzymatic one with reducing sugar titrations coming next..

 

[Jim Welch]

I've never tested in years prior but I'm trying to be more precise as time goes on. All my materials show people using Clinitest tablets and using a color chart. But Bayer discontinued these and it seems urine analysis home kits are going to dip sticks vs tablets. I can't fine Accuvin Residual sugar anymore online either or near me.

how are people testing this now?

Germaine makes AimTab tablets now, just bought this box a couple weeks ago.

 

[mendozer]

it was suggested to me by a more experienced winemaker to ensure everythings done. I used to just taste and do before and after SG but that's not as precise for %
I'm expecting to get aimtabs but the place was closed monday so i have to wait

 

[Jim Welch]

I use this product so I can somewhat accurately know how many carbohydrates are in my wines. I am not diabetic nor have any medical reason to test, and I don't test until bottling time. There is a kit available that I purchased previously from piwine.com that includes a test tube to conduct the test in and an eye dropper to dispense the drops of wine into the test tube. I purchased that box pictured here as a refill for my kit.
If one has a test tube and eye dropper then that kit is not necessary.

Debbie Downer Disclaimer: I do not know if these are 100% accurate as a lab may be, but it is close enough for government work.

 

[TurkeyHollow]

View attachment 84978

So funny seeing your wheeled pooch photo-bombing your picture. Obviously a real ham!
I, too, am interested in testing for RS. I would just like the info for palate calibration. Some wines just have a sweet taste due to vanillans imparted from oak and I sometimes have difficulty distinguishing sweet flavor from unfermented sugar.

 

[Rice_Guy]

alcohol has a sweet flavor, all alcoholic beverages taste sweeter than a similar formula without alcohol. The purpose for formulating to a specific Titratable Acidity is to compensate for the sweetness from alcohol.
glycerol has a sweet flavor, the trace of natural erythritol has a sweet flavor.
vanillin in distilled water is an aroma without noted sweetness, ,,, and yes aromatics are synergistic with sweeteners to produce an impression

So funny seeing your wheeled pooch photo-bombing your picture. Obviously a real ham!
I, too, am interested in testing for RS. I would just like the info for palate calibration. Some wines just have a sweet taste due to vanillans imparted from oak and I sometimes have difficulty distinguishing sweet flavor from unfermented sugar.

HUMM? ? ,,, It always seemed that the reducing sugars was subtracted from the dry solids percentage as an indicator of if the juice was watered down.

 

[mendozer]

i was able to get those aimtabs today. Really easy, both were .01-.05%. I didn't have a test tube so i just used a shot glass

 

[whackfol]

Any update on the accuracy of Aimtabs or alternative? Are they the same or equivalent to Clinitest reducing copper test?

or

I noticed that Vinmetrica now has an RS test. Anyone tried it?

I am concerned with the cost per test. I have the first version of the Vinmetrica which tested only SO2. I really like it for its speed. However, my cost per test is fairly high due to expiration dates of the reagents ($5.40+). I perform about 8 - 10 test per year and a full set of reagents is now $54. The old Clinitest cost maybe a dollar or more and a bottle lasted for a few years if kept well.

 

[BarrelMonkey]

it was suggested to me by a more experienced winemaker to ensure everythings done. I used to just taste and do before and after SG but that's not as precise for %

I think it depends on what your goals are and whether the data are actionable or not. If it's just for the sake of interest, that's fine of course but I would only worry about getting accurate numbers if it's going to change your decision as winemaker.

I'm currently making my first (homemade) sparkling wine, and when I get closer to bottling I will want to know to a fair degree of accuracy what my residual Glu/Fru level is - so that I don't end up adding too much sugar and making bottle bombs. I will probably send it to my local wine lab for analysis. It's more expensive, of course, but I think in my case worth it. For my still whites, I won't bother with the numbers but will be guided by how it tastes. (However, these Aimtabs sound interesting, and if I can get some it might be instructive to compare with the official lab results...)

 

[Rice_Guy]

Well said,

I think it depends on what your goals are and whether the data are actionable or not. If it's just for the sake of interest, that's fine of course but I would only worry about getting accurate numbers if it's going to change your decision as winemaker.

I'm currently making my first (homemade) sparkling wine, and when I get closer to bottling I will want to know to a fair degree of accuracy what my residual Glu/Fru level is - so that I don't end up adding too much sugar and making bottle bombs. I will probably send it to my local wine lab for analysis. It's more expensive, of course, but I think in my case worth it. For my still whites, I won't bother with the numbers but will be guided by how it tastes. (However, these Aimtabs sound interesting, and if I can get some it might be instructive to compare with the official lab results...)

For a still wine, which stopped fermenting, what is the point? taste matters.
I wouldn’t bother for carbonated either (using heavy weight bottles) unless your target is above 2 atmospheres pressure, ,,, which would always be messy to open.

 

[BarrelMonkey]

I wouldn’t bother for carbonated either (using heavy weight bottles) unless your target is above 2 atmospheres pressure, ,,, which would always be messy to open.

Champagne (and many methode champagnoise/traditionelle wines) are typically bottled at around 6 bar (6 atm in round numbers) - I will probably be aiming for closer to 4 bar, so likely some safety margin but enough pressure that I would like to have the data. I'm not currently planning on disgorging but may try to work on my a l volee technique (which I concede is likely to be messy!)

 

[sjjan]

Great @BarrelMonkey that you are making sparkling wine. Are you going for the traditional method? No disgorging by freezing the necks?

 

[BarrelMonkey]

Great @BarrelMonkey that you are making sparkling wine. Are you going for the traditional method? No disgorging by freezing the necks?

I started a thread discussing my efforts so far here - I am definitely making a traditional method wine but haven't decided about disgorging yet. There are nice non-disgorged wines out there - often described as pet-nat, though I think that technically refers to bottling before fermentation has finished. But making a clean, disgorged product has appeal too. I'm not sure how I would freeze the necks in the absence of a commercial facility, maybe a salt/ice bath would do it?

 

[sjjan]

A salt/ice bath definitely works but make sure to also cool the bottles themselves before disgorging. There is quite a bit of info available on the internet on how to do this small scale. Then, depending on how many bottles to do, there are neck freezing devices that freeze 1-3 or larger quantities of bottles for you (the neck that is). See e.g. Bottle neck freezer for 10 champagne bottles 800W - Inderst

 

[winemaker81]

I'm not sure how I would freeze the necks in the absence of a commercial facility, maybe a salt/ice bath would do it?

I've seen recommendations for dry ice.