Slight vinegar? and Sulfite question

[Rocco]

My Malbec/Cabernet 2015 spring from chile seemed to be coming along nicely. In the fall I separated what I had( 21 gallons) into a 6 gallon carboy and a 15 gallon flex tank.

I racked today.

The 6 gallon tank(which had one french oak wine stick in it) is amazing. The 15 gallons in the flex tank has a slight off taste(maybe vinegar but not overly so). Do you think the flex tank allowed too much oxygen exposure? Im not sure what happened but what do you suggest. I hate having 3/4 of the batch ruined--I won't want to serve it given the other 1/4 is so good.

Do you think sulfite will correct? Another difference is I didn't have oak in the 15 gallons--do you think adding oak will help?

Also, people keep telling me differently. I used to measure pH and add sulfite accordingly but it seemed more work than necessary.

Should I add 1/4 or 1/2 tsp per 5-6 gallon carboy of Kmeta? And is it the same dose generally whether the carboy is 5 or 6 gallons?

 

[JohnT]

Are you sure that you cleaned that flex tank thoroughly?
If this is acetobacter, then I would definitely add k-meta.

I do not think that the wood would make that much of a difference in the tartness/vinegar taste.

Another thought: Have you adjusted PH or added any acid since you racked? Is it possible that you over adjusted your wine in the flex tank?

 

[Rocco]

Sulfite dose HELP!

Are you sure that you cleaned that flex tank thoroughly?
If this is acetobacter, then I would definitely add k-meta.

I do not think that the wood would make that much of a difference in the tartness/vinegar taste.

Another thought: Have you adjusted PH or added any acid since you racked? Is it possible that you over adjusted your wine in the flex tank?

I really cleaned the flex tank----easy clean, sulfite and star san......

Same batch and adjustments to both.

pH is around 3.55.

Can you help me with the sulfite dose? In the past I used a chart aiming for 0.5ppm molecular, measured pH, the weighed out the amount etc etc.

I know why I should do this exactly and why I should measure SO2 as the formulas aren't exact and some may get bound up etc.

But I'm realizing my equipment is not so accurate to make this relevant and fractionated teaspoons seems silly right?

My pH meter could be off 0.1, my scale could be off, plus some of the crystals are left on the scale, my measuring spoons aren't precise depending on how I level it and my SO@ accuvin strips aren't all that accurate.

Can't I just put a close dose in that should cover it? Honestly--1/4 tsp in 5 gallons vs a little more or less for my purpose shouldn't matter right? Can those small differences affect taste?

So can you help?

I have a Malbec/Cab and a Cab/Sangiovese that need a top up dose---some tell me 1/4 tsp k meta in 5 gallons, some say a half...I would be happy to go heavier if it won't affect taste?

I have to do an initial dose for my barbera sangiovese that just completed MFL? How much do you think. pH is around 3.5.....

 

[derekjames100]

My container says 1/2 tsp k meta gives 60 ppm in 5 gallons wine. So 1/4 tsp should give around 30 which would be a reasonable target

 

[salcoco]

A 1/4 tsp per 5 gallons is a good standard.

 

[Thormo]

Typically the head space in a flex tank will have a VA odor because the gas will not cover the sides that are now unprotected with wine. Pull the wine out, taste it, and clean the unprotected sides with PBW and Starsan

 

[derekjames100]

Typically the head space in a flex tank will have a VA odor because the gas will not cover the sides that are now unprotected with wine. Pull the wine out, taste it, and clean the unprotected sides with PBW and Starsan

I don't understand

 

[Turock]

It's important to be able to TEST for free SO2 instead of just guessing if there's enough. Acetobacter is everywhere, but it can't produce vinegar during a ferment because of the inhibiting effects of CO2. Vinegar is an oxidative process. So the way to avoid vinegar problems is to limit headspace after the ferment is complete and to use sufficient doses of sulfite.