Sulfite addition to high PH Cab Franc?

[HanksHill]

Want to make sure my calculations are correct before dosing a wine with this much sulfite. I ended up getting some CA Cab Franc grapes that were a little hot. PH right now after Malo is 3.91, measured with a Vinmetrica. Temp in the room is 70 right now from Malolactic, alcohol is about 14 or so. By my calc that would require something like 71ppm to protect? I've never had anything that high before and don't want a sulfur stench, but also don't want oxidized, spoiled wine. Also it's worth noting I added about 50ppm at Crush and it's at about 6ppm free SO2 right now

I've got some Cab Sauv that is perfect - about 3.31ph, 12.8% alc that I plan to dose the normal 25-30ppm and re-measure in a week or so.

Thoughts?

 

[winemaker81]

K-meta to produce 71 ppm should not produce a stench. You need to go a LOT higher than that.

What does the wine taste like? If it's flabby, add a bit of tartaric acid to improve flavor. Once you're satisfied with flavor, check the pH again.

Go light on acid additions, as it's far easier to add more than it is to take some out. Normally, if the pH is high, the wine will be flabby, but it's not a guarantee. I suggest going by taste, not by the pH meter, as the meter won't be drinking the wine.

 

[HanksHill]

K-meta to produce 71 ppm should not produce a stench. You need to go a LOT higher than that.

What does the wine taste like? If it's flabby, add a bit of tartaric acid to improve flavor. Once you're satisfied with flavor, check the pH again.

Go light on acid additions, as it's far easier to add more than it is to take some out. Normally, if the pH is high, the wine will be flabby, but it's not a guarantee. I suggest going by taste, not by the pH meter, as the meter won't be drinking the wine.

It honestly tastes a little harsh, but I think that could be from alcohol as opposed to acid. I was getting BRIX readings all over the place depending on where I sampled from and how much I stirred at crush, I don't think the grapes were terribly consistent, so I kinda assumed in the middle. Definitely a bit jammy. How much tartaric acid would you recommend adding per gallon? I have 21 gallons in a VCT.

 

[winemaker81]

It honestly tastes a little harsh, but I think that could be from alcohol as opposed to acid. I was getting BRIX readings all over the place depending on where I sampled from and how much I stirred at crush, I don't think the grapes were terribly consistent, so I kinda assumed in the middle. Definitely a bit jammy. How much tartaric acid would you recommend adding per gallon? I have 21 gallons in a VCT.

Grapes are not consistent; every grape in a cluster is different. I mix things well, then take brix/sg readings from 3 places. Most of the time they're close, but not always.

IMO? Stir the wine well -- I use a drill-mounted stirring rod, get the wine moving, and switch directions after 30 seconds. Stir for 2 minutes. Then check the SG and pH tomorrow, after the wine has melded. The most common word on this forum other than "the" is "patience".

Given the pH, the harshness is youth and ABV, not acid. While acid is not out of the question, at that pH it's far less likely.

Use an online calculator (there are many) to determine how much tartaric acid to reduce your volume of wine from pH 3.9 to 3.8. Use small increments, and use your tastebuds to determine if you should add more. If in question, stop! Give the wine a month and taste again.

The greatest mistake anyone can make is rushing things. Other than H2S, winemaking is a procrastinator's hobby!

 

[HanksHill]

Grapes are not consistent; every grape in a cluster is different. I mix things well, then take brix/sg readings from 3 places. Most of the time they're close, but not always.

IMO? Stir the wine well -- I use a drill-mounted stirring rod, get the wine moving, and switch directions after 30 seconds. Stir for 2 minutes. Then check the SG and pH tomorrow, after the wine has melded. The most common word on this forum other than "the" is "patience".

Given the pH, the harshness is youth and ABV, not acid. While acid is not out of the question, at that pH it's far less likely.

Use an online calculator (there are many) to determine how much tartaric acid to reduce your volume of wine from pH 3.9 to 3.8. Use small increments, and use your tastebuds to determine if you should add more. If in question, stop! Give the wine a month and taste again.

The greatest mistake anyone can make is rushing things. Other than H2S, winemaking is a procrastinator's hobby!

Thanks - I should mention the wine is dry, what I meant was the BRIX was inconsistent at crush so I made a guess as to what it was at the time on average so as to ascertain what the final alcohol level would be. I'm guessing by the taste that it was on the upper end of my readings. But right now, there's no sugar left in the wine to the best of my instruments' abilities. I will add some tartaric acid with a little distilled water to drop from 3.9 to 3.8 - that would appear to need a free SO2 target of 56 as opposed to 71?

 

[Cap Puncher]

If it tastes balanced, I’d leave it alone. If you are worried about the pH, blend some of your cab sav with the cab franc to bring it down. Blending trials between the cab Franc and the cab sav would be worth your time and effort. I bet blending portions of the 2 will make a better wine. IMO, a better option than tartaric acid and diluting flavors with distilled water.

The 71 free ppm of sulfite does not scare me. As it ages it will drop, especially if you are using a barrel. Some of the sulfite will bind as well so the 71 free ppm you are putting in probably won’t be enough to get to 0.5 M. After adding, Mix.In give it 24 hrs. Stir lightly again and measure the free ppm. It may bleach the color temporarily, but it will come back.

 

[HanksHill]

If it tastes balanced, I’d leave it alone. If you are worried about the pH, blend some of your cab sav with the cab franc to bring it down. Blending trials between the cab Franc and the cab sav would be worth your time and effort. I bet blending portions of the 2 will make a better wine. IMO, a better option than tartaric acid and diluting flavors with distilled water.

The 71 free ppm of sulfite does not scare me. As it ages it will drop, especially if you are using a barrel. Some of the sulfite will bind as well so the 71 free ppm you are putting in probably won’t be enough to get to 0.5 M. After adding, Mix.In give it 24 hrs. Stir lightly again and measure the free ppm. It may bleach the color temporarily, but it will come back.

I ended up adding a little tartaric acid with maybe 4-5oz of distilled water - maybe it was in my head but I thought it really improved the taste of the wine, plus got the pH down to 3.77 which allowed for a little less sulfite as well. Will check it end of next week for free SO2 and go from there.

 

[winemaker81]

I ended up adding a little tartaric acid with maybe 4-5oz of distilled water - maybe it was in my head but I thought it really improved the taste of the wine, plus got the pH down to 3.77 which allowed for a little less sulfite as well. Will check it end of next week for free SO2 and go from there.

The difference is probably not imaginary. With a high pH, the wine was probably at least a bit flabby, and a bit of tartaric perked it.

Wait a month, and try an experiment -- remove half a liter of wine, and add enough tartaric to reduce that amount of wine pH from 3.8 to 3.7. Taste. Repeat a few times, dropping the pH, to see what tastes best. Make the decision based on taste, not pH. The amount of K-meta necessary to achieve a desired level of free SO2 is the least important thing now.

Another thought is to do what @Cap Puncher suggest -- pull a small sample and blend in some CS. You may find that adding 5% or 10% CS will produce a much better result.

 

[NorCal]

Grapes resulting in high pH wines in our area is the norm for me. I’ll try to adjust all I am comfortable with up front, shooting for 3.6. Sometimes I’ll start with 3.9-4.0 and have to settle with 3.7-3.8 wines, after a pound of tartaric goes in the bin. I found that making additions post ferment is playing with fire and I’ve made more wine worse than better. The first number of years, I’d make my additions to the graph, often 70-80 ppm.

For the past 5 years I’ve been backing off the curve and never exceed a 50 ppm addition. One thing driving that decision is that the wine is consumed within 3-5 years. Haven’t had a bottle show signs of premature aging or spoilage yet.