Floating Junk ….. Is This Ok?

[Dave_W]

Strawberry Watermelon Racked to this jug August 31, has some “gunk” at the top. I just noticed today that my airlock had lost enough star San to expose the wine to some potential oxygen.



Is this “normal” or is it something growing because of oxygen?

pH was 3.8 when racked and ABV was 10.5%.

I did not dose with any sulfites at racking, I have since learned that I probably should be. My notes from racking indicate it had floaties prior to racking, which looked like residual watermelon pulp.

 

[winemaker81]

That looks like yeast residue. Nothing to worry about. Oxidation is a slow process, so it's unlikely that O2 is your problem.

Add K-meta. One option for small batches is to dissolve 1/4 tsp K-meta in 5 to 6 Tbsp water, then add 1 Tbsp of the solution to each jug.

I use water in airlocks. It doesn't matter what anyone uses, as long as there is sufficient liquid to block air.

Check your airlocks at least weekly. When the liquid in one is getting low, I replace it and the stopper. The used airlocks and stopper soak in One Step and are dried prior to next use.

 

[Dave_W]

That looks like yeast residue. Nothing to worry about. Oxidation is a slow process, so it's unlikely that O2 is your problem.

Add K-meta. One option for small batches is to dissolve 1/4 tsp K-meta in 5 to 6 Tbsp water, then add 1 Tbsp of the solution to each jug.

I use water in airlocks. It doesn't matter what anyone uses, as long as there is sufficient liquid to block air.

Check your airlocks at least weekly. When the liquid in one is getting low, I replace it and the stopper. The used airlocks and stopper soak in One Step and are dried prior to next use.

Thank you, I plan to rack it this weekend to a new jug so I’ll add the K-Meta during the racking.

 

[wineview]

I’ve seen that before. Not often but I have seen it. I simply pull the bung and drop in 1/4 tsp kmeta. Unlike Bryan, I use a kmeta solution in my airlocks. There have been times when some of the liquid accidentally dripped into the carboy due to meteorological pressure. I feel a kmeta solution is acceptable dripping into the wine.

 

[Rice_Guy]

With a pH of 3.8 and being watermelon I would expect that you taste flavor degradation, not an acetaldehyde burn but it just isn’t true to the juice.

On my part I will add some meta every time I do a manipulation of a carboy. A country wine (low tannin) is likely to have zero ppm of measured free SO2, you are guessing there were floaties, to put the question to bed I take a paper towel strip with a spatula and pull it out. This is followed by a spatula dosing a “pinch” of meta on the surface which I just cleaned.

 

[Dave_W]

With a pH of 3.8 and being watermelon I would expect that you taste flavor degradation, not an acetaldehyde burn but it just isn’t true to the juice.

On my part I will add some meta every time I do a manipulation of a carboy. A country wine (low tannin) is likely to have zero ppm of measured free SO2, you are guessing there were floaties, to put the question to bed I take a paper towel strip with a spatula and pull it out. This is followed by a spatula dosing a “pinch” of meta on the surface which I just cleaned.

If I’m understanding you, basically wipe the bottle to get rid of the gunk then wipe it again with some kind of-meta solution?

Oh, and should my pH have been lower for watermelon?

 

[Rice_Guy]

1) yes wipe the gunk out. This could also with the tip of a steak knife or Q tip.
2) if I think it was growth/ a solid film I will gently pipette a few ml of alcohol followed by sprinkling dry K meta powder on the area. My intention is to have a high concentration of treatment on the infection.
If it looked like brown apple or choke cherry pulp I wouldn’t bother with the alcohol, but dose meta because of the dry airlock.

A trick for lazy airlock monitoring is to put two drops of glycerol in then your Star San/ or meta sanitizer. I don’t use water I would rather a fruit fly drown in a sanitizer.

 

[Raptor99]

Oh, and should my pH have been lower for watermelon?

I would lower the pH to 3.6 or lower. If the pH is too high won't keep as well, and the Kmeta is not as effective.

 

[Dave_W]

Thank you all for the suggestions. It was definitely floating gunk, was not stuck to the jug at all. It was time to rack it off to another jug anyways, so I transferred it and dosed with K-Meta. I will check and adjust pH tomorrow.

Loving the AIO wine pump also!

 

[Rice_Guy]

There are SO2 calculators as winemakers.com. The answer is based on pH, lower pH produces higher levels of free SO2 . My experience in sampling is that on no tannin whites and country wines the test number often is one drop of titrant pushes over the machine low reading, ,, ie it is basically zero ppm.

My pH target on low tannin wines (natural antioxidant) is pH 3.3 to 3.2

The baseline assumption of 0 ppm SO2 each time works. I haven't found research on the topic to suggest a scientific rationale, so I assume that the figure arrived from decades of practical experience by winemakers. 1/4 tsp per 19-23 liters was the figure when I started winemaking 4 decades ago, and I've seen nothing that indicates it's wrong or should be changed. Since it works, I don't bother with relatively expensive SO2 testing, as I see it as a pointless expenditure.

I have adopted the model of adding 1/3 the K-meta dosage each month when I open barrels to top them, because the barrels have to be opened and there is air exposure. I have no intention of doing the same for carboys, as there is no reason to open them. Every 3 months is sufficient.

As to the 3 month rule, SO2 gets used up as it neutralizes things, including oxidation caused by sunlight. Replenishing it is a time-proven rule.

Regarding detection? I've known a few people who could detect SO2 at an estimated 150-180 ppm. I couldn't detect it nor could most people. I've never met anyone who could detect SO2 below that -- it's very likely some folks can, but they don't drink my wine so I don't worry about it.