Acid Reduction with Water (Amelioration)
and Juice-Wine Blending  

Fall Bright, The Winemakers Shoppe
www.fallbright.com Dundee, NY, USA, 607-292-3995 

Grapes grown in the northeastern part of the USA (Finger Lakes Region, NY) tend to be high in acid as opposed to grapes grown in California, USA. Cold climate grapes often need the acid adjusted (usually reduced) prior to fermentation. Depending on the variety, acid reduction via water is a consideration. Any (non chlorinated) potable water used needs to have sugar added adjusting it to 21-22% sugar. To calculate the acid reduction using water, a winemaker uses straight math. Water TA is 0. Take an average, after adding the TA (total acid) of the juice and the TA (0) of the water. Double-check with a follow up acid test and re-check the brix. 

A winemaker should use water sparingly with French Hybrids and Vinifera. We recommend 10 to 15% use of water or less or none. The American varieties such as Catawba and Concord with their robust flavors and higher acids can benefit from amelioration. In some years we have calculated and recommended up to 40-50% water for Catawba. Surely the body will be a little thin but the wine will still be OK.

The harvest of 2009 left us with high acids that seasoned vineyardist have never seen. We ameliorated a Traminette with 25% water and still had a balanced wine with a sweet finish.

Another means of adjusting acid is to blend a high acid juice with a low acid juice. One typical blend is Catawba and Niagara. Niagara tends to have a lower acid if allowed to ripen too long. Blends of Gewurztraminer and Riesling are popular for acid correction. Gewurztraminer tends toward a lower acid and a higher pH when allowed to ripen fully to obtain its varietal spiciness and if picked a bit early or even on time, Riesling will compliment with a higher acid.