WineXpert Fresh Grape Winemaker Screws Up

[dfwwino]

I am about to bottle a VR Zinfandel and noticed it is too tart. In looking through my notes from last year, I noticed that I did acid testing prefermentation and added some tartaric acid. This is what happens when you've been making only fresh grape and fruit wines for 12 years before starting kits. As you kit winemakers probably know, acid testing prefermentation is a mistake for kits. According to Tim Vandergrift in an article in Winemaker Magazine:
Acid testing cannot be done in a pre-fermentation wine kit, as the acids are bound to the sugars in the must by the pasteurizing process, making the readings artificially low.


Apparently, I should not have done what I did. My reading was artificially low and I overshot the best acid level by making the adjustment. It would be nice if the kit instructions warned fresh grape winemaker's like me about this matter.





Edited by: dfwwino

 

[smurfe]

Bummer

 

[grapeman]

The biggest thing with a kit is to simply follow all instructions exactly as given. They have been formulated to give new winemakers an easy to make wine with no adjustments or real measureing except to test the SG to make sure it is within proper range. The average newbie doesn't have a lot of test equipment, so all adjustments have been made at the "factory".


Is it bad enough to use a little calcium carbonate on it? If so treat it as a fresh juice wine prior to bottling and it could improve.

 

[dfwwino]

It is out of balance, but not undrinkable. I am planning on doing a blending test with another red I am about to bottle. If I don't like the blend, I'll then taste some more samplesto see if it is truly too acidic and perhaps try calcium carbonate. I really don't like to use that if at all possible.


I normally do stick to the paint by number instructions. However, I had used pressed Syrah Grapes and mixed in the VR Zinfandel to create a second run wine with a kit. I wanted to make sure the grapes did not affect the acidity level of the juice. I should have waited until post fermentation. Edited by: dfwwino

 

[grapeman]

I want to assure you that you are the only one who ever modified things and screwed up a little! Way to go!

Who hasn't made a slight miscalculation along the way...

 

[dfwwino]

I was rummaging through my supplies and found potassium bicarbonate from a few years ago. If I recall, it is better to use this to reduce acid to avoid any chalky taste and for reducing acid near bottling. Presque Isle wine states:


Potassium Bicarbonate, powder, food grade, 150 grams (0.33 lb). Used to reduce the acidity of musts or wines. Avoid using if the pH is above 3.5, or if you need to drop the acidity more than about 0.3%. Only about 70% of the acid reduction potential is realized unless you cold stabilize after treating the wine. It increases pH more for a given drop in acidity than calcium carbonate, but can be used closer to bottling time. 3.4 grams per gallon will give a potential 0.1% drop in acidity.


It is my understanding that a teaspoon of potassium bicarbonate equals 3.3 grams. So I need to roughly add about 6 tsps to reduce my acidity .1%. I'll be doing some acid testing this week and see how high I am. I also plan to cold stabilize in my modified freezer. I'll let you know what happens.


Yes, I know this won't be my last miscalculation. Now there's a post worthy to make. "All time winemaking blunders." I could spend a few hours writing those down.

 

[dfwwino]

I added enough potassium bicarbonate to reduce the acidity of the Zinfandel to correct this mistake (6 tsp to five gallons)and cold stabilized in my freezer for over two weeks at 35 degrees F. I racked the wine this morning and the wine tastes outstanding. It is no longer too tart and I could not detect any difference in taste from adding the potassium bicarbonate to reduce the acidity. There was a solid, crusty film of acid at the bottom of the carboy that was left after racking. I hope to bottle this wine tomorrow night.


I fermented this VR Zinfandel as a second run on Syrah pomace full of RC-212 after pressing my Syrah from fresh grapes. Due to excess lees, the kit was reduced to five gallons. By the way, I could not detect any kit taste and it has much better body than a typical VR.Edited by: dfwwino

 

[Wade E]

Great job!

Glad to hear that it is fixed and even better that it is great.