Adjusting PH without knowing TA? (prior to primary ferment)

[Jay204]

Is this advisable if my pH is out of an appropriate starting range? I have a pH meter but I will not have sodium hydroxide solution in time for the crush (I have been unable to source it locally). I will be picking up the grapes, destemming and crushing them this Saturday, then pitching yeast Sunday.

I am ordering sodium hydroxide but it will not arrive until after the primary fermentation is nearly finished. Does it make more sense to adjust for pH anyway? Or to leave it be, even if the pH is below or above an ideal range?

 

[GreginND]

Generally, yes. It is always advisable to adjust acid pre-ferment if possible. I have done this many times. Are you trying to raise or lower your pH?

For context, I live in the land of high acid, so I'm usually trying to raise my pH with potassium carbonate additions before fermentation. I have done so many times without measuring TA mainly because my TA's are often screamingly high anyway, so I have no danger of getting it too low. The pH is most important to me for stability, yeast and MLF survivability.

 

[Jay204]

@GreginND I don't know whether or not I'll be raising or lowering pH yet. I'll find out Saturday when I'm able to test the must for the first time. But my understanding (which you reinforced) is that pH levels are more critical to stability than TA levels - so I should be adjusting pH if need be, even without knowing TA.

I just hope that if I'm adjusting pH levels I don't inadvertently adjust the TA in an undesirable way, since I won't know TA values at the start of the process.

 

[NorCal]

My experience is that preferment the wine is very receptive to adjustments. My fruit is typically high pH 3.7-4.0, so I'm dumping in a pound of tartaric into a macrobin of fruit trying to knock it down to the 3.6 level, but I try not to adjust more than .2 pH for fear of raising the TA too high. Not sure if this is valid or not, but a trusted winemaker from UCD told me that a 3.8 wine is microbial stable, so I'll stop there. I have made over 500 gallons of wine with this pH and have not had a spoiled bottle yet (6 year old bottle). It does cause me to use ample SO2, but I also keep that below 300ppm total SO2, which is below our state commercial requirements.

However post ferment is a completely different story. If I adjusted my high pH wine to 3.6 after fermentation, it would make the wine so acidic it would be undrinkable. If I do any post ferment adjustments, I toss the meters and do it to taste.

 

[mainshipfred]

My experience is that preferment the wine is very receptive to adjustments. My fruit is typically high pH 3.7-4.0, so I'm dumping in a pound of tartaric into a macrobin of fruit trying to knock it down to the 3.6 level, but I try not to adjust more than .2 pH for fear of raising the TA too high. Not sure if this is valid or not, but a trusted winemaker from UCD told me that a 3.8 wine is microbial stable, so I'll stop there. I have made over 500 gallons of wine with this pH and have not had a spoiled bottle yet (6 year old bottle). It does cause me to use ample SO2, but I also keep that below 300ppm total SO2, which is below our state commercial requirements.

However post ferment is a completely different story. If I adjusted my high pH wine to 3.6 after fermentation, it would make the wine so acidic it would be undrinkable. If I do any post ferment adjustments, I toss the meters and do it to taste.

Do you really keep your SO2 to near 300? That seems awful high to me. I realize you're dealing with total but still.

 

[cmason1957]

I seldom measure ta preferment. I almost always adjust ph to a reasonable value. I am generally dealing with hybrid grapes and know that the TA will be what it will be, but I have to get the pH down to 3.6, from the start of 4 or higher.

After ferment, if it is to flabby or tart, I might try to adjust the TA some.

 

[Rice_Guy]

* Why adjust?
* pH is like the wind on your hand as your dad drove down the road. We have low pH foods like Pepsi (2.5, with TA of 0.2) or real lemon (pH 2.4 with TA of 5.6). We enjoy the Pepsi or grapefruit (pH 3 TA 1.5) but not lemon juice or vinegar, even though they are in the same pH range. , , pH act as a catalyst which activates Kmeta or deactivates bacteria or destroys shelf life . . . . ie pH is controlling how well (safe) the ferment goes.
* TA is like the splat/power on the windshield (or your hand out the window). A bug we say noticeable, run the wipers but ignore it. A rain we ignore. A deer and we say oh sh*# and it stops us in our tracks, like straight lemon juice, , we spit it out, , or sugar it up. As cmaison says why bother pre ferment, TA is a flavor issue.
In the scheme of things I look at Chile juice buckets (0.2) and say low TA/ must be a hot growing region, but it makes wine. California buckets are in target and Midwest hybrid grapes are high (1.2 or so). Sometimes this is good as the cranberry here with aTA at 1 or Midwest grapes which score higher on aftertaste when judging state fair. . .

what depth of flavor do you enjoy? A guess is if you can enjoy the must flavor it is in a workable range, , , without waiting forTA chemicals

 

[salcoco]

adjust ph preferment and adjust TA post ferment based on taste.

 

[Jay204]

I appreciate all of the input! This makes me feel much better about not being able to calculate TA on crush day. I'll adjust for pH and worry about TA afterwards. Does it matter when I adjust the TA? ie. before MLF or post MLF?

For pH, as a general rule of thumb, should I be targeting a 3.5-3.8 pH range (according to the morewine manuals)? @NorCal do you usually target a 3.6?

 

[NorCal]

I appreciate all of the input! This makes me feel much better about not being able to calculate TA on crush day. I'll adjust for pH and worry about TA afterwards. Does it matter when I adjust the TA? ie. before MLF or post MLF?

For pH, as a general rule of thumb, should I be targeting a 3.5-3.8 pH range (according to the morewine manuals)? @NorCal do you usually target a 3.6?

If I can hit 3.6 pH pre-ferment by adjusting .2 or less with the grapes I get here in the Sierra Foothills, I'm a happy camper.

 

[NorCal]

Do you really keep your SO2 to near 300? That seems awful high to me. I realize you're dealing with total but still.

It is not that I keep the SO2 at 300, I don't exceed that number. Considering 4.0+ pH wine, the target free SO2 level is around 100 and aging my wine in barrels, consumes the free SO2 twice as fast as it does in carboys (measured it, same wine over same period), it adds up pretty quick. 50 pre-ferment, 90 post mlf, leaves 160 ppm over then next 9- 16 months. Say 50 ppm adds every 3 months, it can approach 300 pretty quick. Thus the driver to get the pH down around 3.6, where my target free SO2 level is 40-50.

 

[BI81]

Check out "The Inside Winemaking" podcast #67 https://www.insidewinemaking.com/#/067/ with Dave Nakaji, winemaker for Sebastiani Vineyards and Winery. He discusses his approach to pre-fermentation pH and getting to a 3.63, he doesn't factor or adjust to TA at all. It's a pretty interesting conversation.

 

[Jay204]

@BI81 - Perfect podcast to answer my question. Thanks!

 

[Ike64]

A couple of thoughts.
If your pH is too low, then you might have a hard time keeping the yeast alive until primary fermentation is complete.
If your pH is too low, then your sugar levels might be very low too.
I think chaptalization (adding sugar water) would be the best way to remedy both. Plus you get more wine!
For what its worth, I aim for pH of 3.3-3.4 and Brix of 24-25.