Dehydrated grapes

[John Campbell]

We have a small Zinfandel vineyard in Sonoma County. We have scarce water and the ten year old vines are dry farmed. There is some shriveling and raisining of some grapes. The Brix is measuring at 30.1! but the Ph is around 3.12. Would watering the vines now help reduce m and drop the Brix? Or is this something that needs to be addressed by adding water to the mist after harvest. I’m reluctant to harvest now with the low Ph. Obviously not the best viticulture practices this year!

 

[MrFrench]

Have you calculated the water required to reduce the brix, and it’s associated impact on pH?

 

[John Campbell]

Have you calculated the water required to reduce the brix, and its associated impact on pH?

I have not. I’m not sure how to do that absent knowledge of the weight of the harvested grapes and volume of the must.

 

[winemaker81]

Watering back will both lower the brix and raise the pH. I'm more concerned about the brix, as acid can be adjusted through various means.

What is your thought for a target brix? I did quick math regarding brix on the amount watered back

Brix:​	30.1​
5%​	28.6​
10%​	27.1​
15%​	25.6​
20%​	24.1​
25%​	22.6​

At the current brix, you'll need a LOT of water to get down to a normal level, say 24 brix. If you wait longer on pH, you're going to need even more water.

I don't have a clue what effect that much water will have on the pH, since pH is a logarithm, e.g., a curve, not linear.

My concern is adding that much water is going to make a thin wine, even if it's high ABV.

If the wine is acidic, you can do cold stabilization, MLF, yeast strain that eats malic (Renaissance Avante), potassium bicarbonate, backsweetening slightly, and/or blending with another wine.

Another thought is to NOT water it back -- make a Port from it. Although depending on your quantity, that could be a lot of Port. Also consider multiple batches exercising different techniques.

 

[MiBor]

We have a small Zinfandel vineyard in Sonoma County. We have scarce water and the ten year old vines are dry farmed. There is some shriveling and raisining of some grapes. The Brix is measuring at 30.1! but the Ph is around 3.12.

I'm a big proponent of the "when life gives you lemons..." approach when it comes to winemaking. If I had those grapes to make wine with, I would make the best Zin appassimento style that I could. The best part is that most grapes are already raisined and you don't have to wait for that to happen or come up with a drying rig. You can easily find details about this award winning winemaking process online.

Here is a short presentation of the appassimento process:





https://www.lodiwinelabs.com/products/pasteur-blanc?_pos=1&_sid=7c70a0b88&_ss=r&variant=24299993862

 

[Hazelemere]

We have a small Zinfandel vineyard in Sonoma County. We have scarce water and the ten year old vines are dry farmed. There is some shriveling and raisining of some grapes. The Brix is measuring at 30.1! but the Ph is around 3.12. Would watering the vines now help reduce m and drop the Brix? Or is this something that needs to be addressed by adding water to the mist after harvest. I’m reluctant to harvest now with the low Ph. Obviously not the best viticulture practices this year!

I'd ferment with EC-1118 yeast to 18% alcohol (i.e. port style) with 10% by weight water solution so all of the sugar ferments. Then blend it next year to try to get the alcohol below 15%. so it goes malolactic. You can try adding 71B to EC1118 this year but 71B will be overtaken by the alcohol at 14%. Make sure to add vitamin B containing nutrient to keep the EC-1118 alive. You'll end up with 16.8% alcohol. The other option is buy some Amador or Lake County zinfandel this year to drop the brix in which case I'd dilute the whole batch with 10% water. You can also dilute your zin with 15% water in which case your alcohol will drop to 15.6%. You can blend this year's zin with next years with no water added say 50/50 in which case water dilution drops to 7.5% If you get the alcohol down to something like 14.9% or lower you should get something decent. Good luck.