PH & TA in Black Berry (Copuntry) Wine

The TA of wines naturally increases during fermentation due to the formation of acids (e.g. succinic, lactic, etc). In grape wines, with their predominantly tartaric acid composition and reasonably high level of potassium, this increase is offset by a reduction in acidity due to potassium bitartrate precipitation (as the alcohol content increases during fermentation, the solubility of potassium bitartrate decreases and it is precipitated). The decrease this causes is usually about equal to the increase in acidity that occurred during fermentation, resulting in a net increase in TA of 0-0.5 g/l.

In non-grape wines, the acid profile of non-grape fruits, however, is usually naturally dominated by malic and citric acids. Provided that no significant portion of tartaric acid has been added to a non-grape must and the predominant acids are non-tartaric, a significant acid reduction due to potassium bitartrate precipitation will not occur. (Likewise for grape wines with low K content etc). Thus, it can be expected that a non-tartaric must with a relatively natural acid profile will undergo a TA increase during to fermentation, and a subsequent drop in pH.

This means that non-tartaric musts should be treated with this in mind. A blueberry must TA of 4 g/l (as tartaric) is perfectly acceptable for a wine that will be dry - and should *not* be acidified (depending on style). I've never seen this information presented in any book on non-grape winemaking, and this fact represents perfectly the lack of advanced knowledge in the non-grape wine world. Ben

Improved Winemaking

You can reduce the TA and PH abit with MLF

MLF will reduce the TA but *raise* the pH. Perhaps that's what you meant.

Other options (aside from dilution and sweetening) are to use malic metabolising yeast for alcoholic fermentation, chemical deacidification, or carbonic maceration.

Ben

Yeah, I posted with out thinking it out.

First of all I would like to thank Ben for his post. You have confirmed my thinking although I am by no means an authority on this or any subject concerning wine making. So called country wines are the extent of my wine making. I will tell you how I attempted to solve the problem and only time will tell the results.

1. I added 6 grams of Potassium Bicarbonate to the #1 5 gallon batch and measured the following change. PH increased from 2.81 to a PH of

1. Added 15 grams of Potassium Bicarbonate to the #1 batch and measured the following changes. PH increased from 2.89 to a PH of 3.08. TA decreased from .675 to a TA of .57.
2. Added 5 grams of Potassium Bicarbonate to the #1 batch and measured the following changes. PH increased from a PH of 3.08 to a PH of 3.3 and TA decreased from .57 to a TA of .45. The wine had been stabilized for about two weeks prior to these changes but not clarified. By adding the Potassium Bicarbonate just a little at a time the foaming was minimal. I did not cold stabilize because I did not want any acid reduction, on an increase in PH. My understanding is that cold stabilization will reduce Tartic Acid and since the predominant acid in blackberries is Malic, that is the reduction I was looking for. Hopefully that is what I got. As I said before only time will, but I am happing with my PH and TA readings.(My years in maintenance made me do this.) I will post again in two or three months and give a final report. Once again, My thanks to Ben for his information and others for their posts. Aubrey

Sweetened to taste at SG 1012 and final PH was 3.38 with TA at .60. Taste at this time was excellent. final report after a few months to settle. I assume the change in PH and TA was the result of the water used to melt the sugar raising the Specific Gravity. At any rate, so far I am pleased with the final results. Aubrey

Hi Ben

Outstanding post. Thank you. This topic has been discussed for years in this group without anyone taking much notice (or so it seems). In all of nature the grape is unique in it's acid composition. The techniques for dealing with this is highly specialized and highly specific to grapes, and these techniques have little if any application for non-tartaric wines. Tartaric is seldom the best choice for adding to non-tartaric wines and MLF in a Malic (non-tartaric) wine can be devastating. Unfortunately, the great majority of the literature is devoted to "the grape" and these differences are not well covered in "country" literature. Thank you for raising the level of attention in this group about such things.

Frederick

Frederick,

Thank you for your kind words. I hope this kind of information can be shared and spread throughout the non-grape winemaking world, hopefully leading to a general increase in quality.

Ben

techniques

Unfortunately,

Ben

I hope this kind of information can be shared and spread throughout the _grape_winemaking world, hopefully leading to a_decrease_in getting "grape" answers to "country" questions !! A bit harsh, perhaps, but true none the less.

Frederick