Page 12 - Grapevine May-June 2019
P. 12
In The Winery
or longer and re-approach in the same fashion Calculation:
by smelling each wine individually and select the
glass or glasses that smell the best. In my opinion there is no truly reliable calculation
for this test to determine quantitatively how much
7. After determining that the wine is actually copper sulfate to add. In most cases it is best to
changed and changed for the better, have the add small quantities of copper sulfate to a wine
person that added the copper sulfate to the nearing the range of 1.0 gram per 1000 gallons to
glass reveal the glass that was treated. as low as one-half a gram per 1000 gallons to clean
up small defects. This is a good starting point.
8. Mentally extrapolate after collecting all the data From experience, you may start to recognize a wine
whether the addition of copper sulfate had a that may need more Copper Sulfate to combat
positive impact on the wine or not. Be aware more pungent aromas. This chemical is a strong
not to select the copper sulfate addition wine oxidizer so use limited amounts. Overuse could
– just because it is different. The wine should have serious downsides to your wine.
smell better – not just different.
Removal of Copper After Use
9. Once an addition is deemed helpful, proceed
to making the adjustment in the cellar as refer- In most cases, only small amounts of copper sul-
enced below under calculation. This test is not fate are used to clean up a wine so we rarely need
quantitative. to address lowering the copper content in the
wine. Please recognize when larger quantities have
This test is sometimes known as a triangle test. been used. Use an outside laboratory to actually
measure the amount of residual copper in your
Spicing it Up! wine. In many cases, for white wines treated prior
to protein fining with bentonite, they may clean up
Once you and your assistant get comfortable on their own. The author has seen copper levels
with the test, he or she can be instructed to switch drop significantly after protein fining and filtering
around the treatment regime to perhaps treat two of white wines. Many years ago, wines may have
of the three wineglasses. This will keep the person needed a “Blue-Fining” but one rarely has those
smelling the wines on their toes to actually identify issues in today’s winemaking plus they are not per-
what wine smells better and to truly focus on the mitted in the United States.
improved wine.
The Future
Referencing the fact that a spit cup was listed
under the “Tools needed” list above, one should According to some scientist we need to more
have their spit cup ready. This should be used if closely look at nutrients and their role with the
by habit one should accidentally taste the wines. yeast. In some cases too much or too little nutri-
Remember, technically, Copper Sulfate is a poison ents may cause Hydrogen Sulfide production and it
so winemakers should resist tasting our trails and is thought to link into the micronutrients. Nitrogen
only focus on the aromas. issues may not be the driving factor here. This will
help us stay away from using copper sulfate, which
One can build on this test to correct Mercaptans, does have adverse affects to the wine in addition to
also. Mercaptans are Hydrogen Sulfide based com- cleaning the wine up sensorialy. Until that time we
pounds that have transformed to a more compli- need to address the problem in a fashion we can,
cated chemical compound. Ascorbic acid trials may such as copper sulfate. Stay tuned.
need to be tested for effectiveness in these cases.
Reference other sources to review this process as it Other Helpful Tips
will not be covered at this time.
• Caution is expressed not to confuse a change in
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