High acid reds and high TA/high pH

[spaniel]

I've made several vintages of Foch and Oberlin Noir. Here in central Indiana, my issue is that our season stays so hot so late (often with humidity) that the grapes reach such a Brix that they will either start to rot on the vine or the wasps take them before the TA gets down to a reasonable level. So I am forced to pull them.

I've tried "acid eating" strains, malolactic, and cold stabilization. I have either a) failed to bring down the TA enough and ended up with a tart wine, or b) failed to bring down the TA enough AND taken the pH to the high end of range, ending up with a both tart and flabby wine.

I'm open to some pointers from those who may have dealt with this; there's a reason people focus on whites around here.

I have not yet resorted to trying Acidex or anything like that. I may try it this year. Thus far I've tried to deal with it in the wine, this year I would like to gather information and try dealing with it primarily in the must. Specifically any tips if I end up in a high TA/high pH situation again.

After a couple unfortunate crop losses I've got a great set of Marquette going, I don't want to waste it!!!

 

[NorCal]

What is your brix as well as pH, TA before and after adjustment?

 

[user 36973]

hey spaniel - I'm also in central Indiana and feel your pain about dealing with high pH/TA grapes.

Foch can have a high TA but often has some margin for deacidification. We've been getting Foch from NW Illinois the last few years and just planted an acre of it last year ourselves. I'm not convinced the grapes will sufficiently drop acid with additional hanging. Birds, sour rot, rain and fruit flies all pose greater risk to the grapes than higher acid, IMHO. I am growing its sister grape Leon Millot which can also have the same issues. I generally harvest it the first week of September.

Norton is the other problem child grape of ours that comes in with no pH headroom to deacidify. I haven't worked with Oberlin though.

Options that I've used are (in rough order of preference):
1) Blend in a low acid wine for final balancing prior to bottling. I find this to be a great option since you have complete control of the final blend for both flavor and acid. The blend also builds complexity into wines that may lack it to begin with. I love the french-american hybrid grapes but their flavor profile is simple, when compared with a Cab or Merlot.
2) Put the wine through malolactic while barrel aging.
3) De-acidify if possible but I don't allow the pH to top 3.75. Careful about how much the pH will increase with malolactic.
4) Cold stabilize the wine to drop out some tartrate crystals. Again watch the pH as this will cause it to rise if it is above 3.65.
5) Consider acid consuming yeast strains. Though I'm not convinced this is necessary when followed with malolactic. Also not sure if it is worth using an inferior yeast like 71B instead of a better red wine yeast.

Good luck

 

[spaniel]

What is your brix as well as pH, TA before and after adjustment?

A couple examples:

Oberlin Noir 2015
Must: 1.765% TA (by buret titration), 21 Brix, pH 3.13
Fermented with 71B, cold stabilized
Finish: pH 3.46, 0.88% TA
Used potassium bicarbonate and another cold stabilization. Didn't bother re-measuring numbers as my palate told me the pH went too high and the acid not low enough; gave up and drank it myself.

Foch 2015
Must: 20 Brix, pH 3.76, 1.04% TA. Brought Brix to 22.
Didn't want to add more acid to address the pH so I hoped for the best. Fermented with 71B, malolactic done and visually confirmed active, cold stabilized.
pH 3.80, 0.72 TA. Tart and flat. Decided to throw in the towel and use as a test batch for Acidex. Did that and cold stabilized.
pH 3.98, TA 0.70%.

 

[spaniel]

hey spaniel - I'm also in central Indiana and feel your pain about dealing with high pH/TA grapes.

Foch can have a high TA but often has some margin for deacidification. We've been getting Foch from NW Illinois the last few years and just planted an acre of it last year ourselves. I'm not convinced the grapes will sufficiently drop acid with additional hanging. Birds, sour rot, rain and fruit flies all pose greater risk to the grapes than higher acid, IMHO. I am growing its sister grape Leon Millot which can also have the same issues. I generally harvest it the first week of September.

Norton is the other problem child grape of ours that comes in with no pH headroom to deacidify. I haven't worked with Oberlin though.

Options that I've used are (in rough order of preference):
1) Blend in a low acid wine for final balancing prior to bottling. I find this to be a great option since you have complete control of the final blend for both flavor and acid. The blend also builds complexity into wines that may lack it to begin with. I love the french-american hybrid grapes but their flavor profile is simple, when compared with a Cab or Merlot.
2) Put the wine through malolactic while barrel aging.
3) De-acidify if possible but I don't allow the pH to top 3.75. Careful about how much the pH will increase with malolactic.
4) Cold stabilize the wine to drop out some tartrate crystals. Again watch the pH as this will cause it to rise if it is above 3.65.
5) Consider acid consuming yeast strains. Though I'm not convinced this is necessary when followed with malolactic. Also not sure if it is worth using an inferior yeast like 71B instead of a better red wine yeast.

Good luck

My Foch harvest date is exactly the same as yours.

I wish I could blend but thus far I have this issue with both (ie all) of my reds. Perhaps my Marquette will turn out on its first try and give me options.

I've tried everything else on the list, and now that I look at my notes, Acidex as well. I think I will try acid removal at the must stage this year and hope this has less impact on the flavor.

 

[NorCal]

Wow, I had no idea how challenging these grapes were. I'll stop complaining about our 26 brix, 3.9 pH grapes.

 

[stickman]

The acid adjustment issue is rather complicated and most of us have had to deal with it one way or another. Cold climate grapes have additional issues to consider. I stumbled across this document which may help with understanding how to deal with acid adjustment in general, but it also contains information specific to cold climate grape must adjustment. Just my opinion, but this seems to be a good write-up with technical as well as practical information.

View attachment MWP-Acidity-in-American-Wines.pdf

 

[spaniel]

The acid adjustment issue is rather complicated and most of us have had to deal with it one way or another. Cold climate grapes have additional issues to consider. I stumbled across this document which may help with understanding how to deal with acid adjustment in general, but it also contains information specific to cold climate grape must adjustment. Just my opinion, but this seems to be a good write-up with technical as well as practical information.

I've read a lot on this topic, and this is perhaps the most informative document I've seen. Thanks!!!

 

[spaniel]

Harvested a couple weekends ago. We had a weird year; lots of water in the spring and through the third week of July and then NOTHING. Very dry, air as well. So instead of having to pull grapes before they rotted I could let them hang about a week longer than normal. pH on all three reds (Oberlin Noir, Foch, and Marquette) was in the happy range. I could not measure TA as my NaOH had gone bad. Sugar not as high as I would have wanted ideally but I'm very happy that I have the potential to make decent red this year!

The Marquette had to get so ripe that I lost about 25% of the crop to over-ripe to get the TA down this far. Should have picked a week earlier but work didn't allow. The Oberlin was strangely uniform in ripeness, you could tell it was different than normal as all the grapes were perfectly the same color all down the row.