How does the TA/pH adjustment process work?
The TA and pH Adjustment process makes use of an ultrafiltration membrane-based process coupled with ion exchange resin to reduce pH and TA effectively and efficiently. The key difference between this two stage process and direct wine on resin processing is the separation of the phenolics and anthocyanins from the wine prior to passing the permeate through the resin bed.
Why is this a big deal? The pH conditions within the resin are severe (as high as 14 in anion beds and as low as 1 in cation beds). Subjecting high molecular weight or delicate aromatic compounds to pH extremes by using ion exchange only is not desirable due to the potential side effects of the large pH shift on the chemistry of the wine. Direct resin contact was used extensively in the 60’s and 70’s, when quality was not as important as it is today or when membranes were in their infancy. Using membranes to first separate the wine into two streams drastically improves the quality of the end product.
Why reduce TA or pH?
We are seeing more and more vineyards producing fruit with high pH and TA conditions. The side effect of this high pH and TA juice are conditions ranging from stuck ferments to high sulfur levels and flabby wines. Adjusting the TA and pH to be more in line with ideal conditions is advisable and creates peace of mind during the winemaking process.
When can I process my wine or juice?
White juice can be processed straight out of the press or as finished wine. When running juice, we filter a portion of the juice prior to it being fed to the ultrafilter. Permeate exiting the ultrafilter is then passed through the necessary resin columns in order to decrease pH or decrease TA or both. The processed permeate is then recombined with the original wine. We can also process white wine after fermentation.
For red wine processing, we recommend working on the wine only. It is much more difficult to process red juice due to skin contact requirements. It is possible to work on a small portion of the juice, but not recommend due to timing and fermentation issues.