pH drift: Apple products

[Rice_Guy]

Many of the wines I did in 2022 had a percentage of fresh/ unpasteurized apple juice in them. That seemed OK since juice would have more fruit impact than formulating country wines with water. BUT now that I am clearing out the carboys I am seeing all the pH numbers have drifted up. Everything starts between 3.2 and 3.5. Now I have readings as 3.84, 3.90, 4.18, 3.86, etc. on the first couple I acidified back to 3.5, added meta and bottled ,,, Above 4 I tossed based on flavor.

Best guess is that I have wild Malolactic fermentations doing this. Other guesses? ? ? (I am not set up for chromatography/ never intentionally ran MLF on grape). (yes pH is recalibrated and I tried a new probe). Another trend is a low level bitter note (Lallemand notes this could be glycerol being metabolized by wild LAB)

Back to the present, I have looked at the 2023 carboys. They aren’t as bad as 2022 but have drifted up as pH 3.6, 3.64, 3.62 with gravities as .995, .994?
What would you do to salvage 2023? ,,, What would you do to prevent drift in 2024? ,,, Am I missing something about apple?

 

[Hazelemere]

Many of the wines I did in 2022 had a percentage of fresh/ unpasteurized apple juice in them. That seemed OK since juice would have more fruit impact than formulating country wines with water. BUT now that I am clearing out the carboys I am seeing all the pH numbers have drifted up. Everything starts between 3.2 and 3.5. Now I have readings as 3.84, 3.90, 4.18, 3.86, etc. on the first couple I acidified back to 3.5, added meta and bottled ,,, Above 4 I tossed based on flavor.

Best guess is that I have wild Malolactic fermentations doing this. Other guesses? ? ? (I am not set up for chromatography/ never intentionally ran MLF on grape). (yes pH is recalibrated and I tried a new probe). Another trend is a low level bitter note (Lallemand notes this could be glycerol being metabolized by wild LAB)

Back to the present, I have looked at the 2023 carboys. They aren’t as bad as 2022 but have drifted up as pH 3.6, 3.64, 3.62 with gravities as .995, .994?
What would you do to salvage 2023? ,,, What would you do to prevent drift in 2024? ,,, Am I missing something about apple?

Apple acid is malic acid. If you ferment apples you don't want malolactic fermentation. 70 ppm total sulphite will prevent it. If the wines are balanced leave them alone. If they are flat add citric acid.

 

[Rice_Guy]

I thought it would risk less metabolic chemistries if I went with reagent grade phosphoric acid.
Running a sulphite calculator at pH 3.9,,, wow I didn’t want to add that much.

 

[Hazelemere]

I thought it would risk less metabolic chemistries if I went with reagent grade phosphoric acid.
Running a sulphite calculator at pH 3.9,,, wow I didn’t want to add that much.

I am a professional chemist and don't understand what you are saying. Try saying it a different way. To start with post absolutely everything that you did from start to finish i.e. fruit, how you processed it, yeast, fermentation conditions, all additive and doses with enough detail so that anyone could reproduce exactly what you did with your fruit. If you do that I or someone else can probably help you.

 

[BigDaveK]

I've been dealing with a similar issue so I'm just thinking out loud and adding my very crazy two cents.

I often have changes in pH of .2, a good number of .4, and 3 of .7! Some is due to normal fermentation and I'm fine with that. The others? Wild MLF? It would have to be rampant and I'm not ready to accept that just yet. What's left?

Crazy idea #1 - could some fruits have elevated levels of potassium (from the soil) that release K+ ions during fermentation/aging making the wine more alkaline?
Crazier idea #2 - could kmeta under the right conditions release K+ ions?

Like I said, thinking out loud. I'm not a scientist but I do have a lab coat and goggles.

 

[winemaker81]

A wild MLF is certainly a possibility, and I've had pH change radically from pre-fermentation to post-fermentation. If it were me, in the future I'd add 3/8 tsp K-meta after fermentation completed.

 

[MiBor]

My opinion is that the pH shift you describe is consistent with malolactic conversion. I don't think anything else can explain it, short of instrument malfunction. You must have a strain of MLB that's present in your wine making area, that converts slowly, without much CO2 release.

If it was my wine I would try to put some of the malic acid back in, based mostly on taste, using lab grade D-malic that doesn't get converted by Oenococcus oeni. It could be a fun activity to bench test the malic addition ratio with some of the wine club members.

I think you really have to figure out how to overcome this problem, because that MLB strain is not going away any time soon and every batch of wine you make at home will be afected by it. Higher k-meta additions may work to stop the conversion, but you'll be doing an excessive "mummification" of wine instead of keeping it as natural as possible. Maybe lysozyme is the answer, or sterile filtering. You'll have to try and find out what works for your wine.

 

[Rice_Guy]

@Hazelemere todays batch.

* mixed 2023 crop HoneyGold and Macintosh from my garden, experiment crush with the Vinters club’s apple crusher, free run juice 1.072 (~9.6 potential) pH 3.4, add pectase
* Sep 28 add Fermaid O and TR-313 ~. 50F
* add about 1.7Kg apple with 50% Prairie Fire crab apple (tannin source)
* at 1.060 add Fermaid O 4 gm
* re-press approx 1 gallon out of pulp and add to the primary, 71F
* at 1.024 rack to a six gallon (Oct 2)
* add more pectase, still cloudy
* Jan 15 sample at 1.005 / pH 3.82/ TA 0.92%, >> add 27.3 grams phosphoric, >> add another 10.2 gm phosphoric acid >> pH 3.5 / TA 1.06%
* Jan 22 filter with a #3 BonVino pad

 

[Rice_Guy]

of keeping it as natural as possible. Maybe lysozyme is the answer,

This is what I was wondering about ,, ??? Lysosome is available in town so I got 50gm this afternoon. Have no experience with the product though.
Option B, traditional method, drop the pH to 3.2 and load it up with meta. (so far I am using phosphoric acid since it shouldn’t get metabolized)
Option C, pasteurize
Option D, Lallemand suggests I order a kilo of Bactiless which isn’t available in town and I have no experience with.

The frustration / fear is I have used Prairie Fire as a smooth tannin source in almost everything since 2022. How do I stop this this year.

 

[Hazelemere]

@Hazelemere todays batch.

* mixed 2023 crop HoneyGold and Macintosh from my garden, experiment crush with the Vinters club’s apple crusher, free run juice 1.072 (~9.6 potential) pH 3.4, add pectase
* Sep 28 add Fermaid O and TR-313 ~. 50F
* add about 1.7Kg apple with 50% Prairie Fire crab apple (tannin source)
* at 1.060 add Fermaid O 4 gm
* re-press approx 1 gallon out of pulp and add to the primary, 71F
* at 1.024 rack to a six gallon (Oct 2)
* add more pectase, still cloudy
* Jan 15 sample at 1.005 / pH 3.82/ TA 0.92%, >> add 27.3 grams phosphoric, >> add another 10.2 gm phosphoric acid >> pH 3.5 / TA 1.06%
* Jan 22 filter with a #3 BonVino pad
View attachment 109620

How much and when did you add sulphite to how many gallons? What form and when? What yeast did you use?

 

[ibglowin]

The way this thread reads (at first) is that your having issues with iPhones and or iPads! LOL

Just a thought but have you considered your pH meter is in need of cleaning (probe)? Maybe even an entire pH meter swap out if need be.

What about a loss of carbonic acid from CO2 after AF is complete which would make the pH shift up slowly.

 

[MiBor]

Option D, Lallemand suggests I order a kilo of Bactiless which isn’t available in town and I have no experience with.

Lodi Wine Labs sells 100g of Bactiless for about $42+shipping, if you want to go that route.

Bactiless100g

 

[Raptor99]

I have not experienced spontaneous MLF as far as I know. So I am curious about it. I normally treat my fruit must with Kmeta before starting fermentation. The standard dosage is usually 0.44 g Kmeta/gal. Would that be enough to kill off any wild MLF bacteria?

 

[Hazelemere]

I have not experienced spontaneous MLF as far as I know. So I am curious about it. I normally treat my fruit must with Kmeta before starting fermentation. The standard dosage is usually 0.44 g Kmeta/gal. Would that be enough to kill off any wild MLF bacteria?

31 ppm of total sulphite is what you are getting if you are using Imperial gallons. That won't kill MLF bacteria. When your fermentation stops if you treat with bentonite that number goes to zero or close to zero. If you don't use bentonite it still drops. I usually approximate "free" sulphite as 1/3 of total sulphite for a wine with normal acidity. So unless you added more sulphite ferment the MLF have everything they need i.e. low alcohol, room temperature and low total sulphite to work on your apple malic acid. If you got the total sulphite up to say 70 ppm (~23 ppm free) you should be able to stop MLF especially if you cool the wine or boost the alcohol. You have inadvertently created a perfect environment for MLF. The ratio between free and total sulphite drops as the pH goes up. If you want to salvage your wine sulphite it now and get it cold for a while without having it or your airlocks freeze. That should stop the MLF.

 

[Rice_Guy]

I have not experienced spontaneous MLF as far as I know. So I am curious about it. I normally treat my fruit must with Kmeta before starting fermentation. The standard dosage is usually 0.44 g Kmeta/gal. Would that be enough to kill off any wild MLF bacteria?

In ‘22 I was using 0.2gm Kmeta per gallon with a target pH of 3.2 to 3.3 at 12% ABV. In ‘23 I started to think red grape on this forum will let 3.7 go, cider folks live at 5.5% ABV, ,,, so I “got lazy” and let pH 3.5 / less than 11% ABV go while increasing to 0.3gm meta per gallon. ,,, I am not currently monitoring free SO2. . I haven’t found a good reference on where the rules are that cider folks work against for quality. ,, I have heard fermented cider can go wild/ it is a learning curve.

@Raptor99 , the symptom is pH is creeping up. This symptom is pushing me to set up malic acid chromatography as a diagnostic. I find it interesting that TA hasn’t drifted down which we would expect from O onei.

 

[Rice_Guy]

Lodi Wine Labs sells 100g of Bactiless for about $42+shipping,

Thanks, have some ordered, ,,, (fingers crossed)

 

[Rice_Guy]

this subject is a rabbit hole; From a Lallemand, Importance of Malolactic Fermentation

I pick up bitter notes on many of these wines

 

[Rice_Guy]

I am scratching my head about bitter flavor. It seems to mask other flavors in the end.

My worst pH shift so far has been a strawberry apple starting at pH 3.45 and this month up to 4.18/ with more bitter note that sugar would not mask.
* Jan 14, 2023, 5.6 kg strawberry,, thaw~ 1.033, add initial sugar for a calculated 1.080
* 1.6kg crabapple washed in apple (tannin source),
* 0.5gm Kmeta, 4gm Fermaid O, Bravo yeast (high glycerol/ no H2S type), 17C, Jan 16th
* Jan 19 press in nylon filter bag to remove pulp, 1.082/ pH 3.45
* add Bravo yeast again
* add apple juice to make 3 gallons (a low TA pail/ 0.21%/ 1.072 pH should be 3.4), add calculated sugar 2.6kg, Jan 22 measure 1.088 (freezer apple juice is treated with pectase and 0.2gm Kmeta/ gallon when pressed)
* Jan 28 1.055/ 17C, add 4gm Fermaid O
* Jan 31 1.037, Rack to a three gallon glass, add .44kg apple to fill carboy
* Feb 22, 1.005, rack off lees, 0.6gm Kmeta, noted nice strawberry aroma
* Jan 8, 2024, pH 4.18/ 0.996, add 0.8gm Kmeta, off bitter flavor notes
* Rack Jan 9th, 10gm phosphoric acid >> pH 4.02, still objectionable bitter note, bench test sugar, bench test acid blend
* ??? find WMT thread on lactic acid bacteria and start heading down the rabbit hole about wild fermentations,
* survey the WisVinters five members out of 60 have lysozyme, can’t find anyone who actually use it.
* add salt to two gallons and use to melt ice off the sidewalk. Neighbors can pick up the fruity/ berry aroma in that application. ;(

LEARNING at this point; pH needs to be monitored more/ the old way to control is with low pH and more Kmeta; as a diagnostic chromatography could be run; apple is different than grape it takes some learning curve; I need to be less sloppy if I am trending toward hard cider 8% ABV, it isn’t as easy as country wines at 12%

A guess low level bitter flavor note is on many white grape wines at the vinters club and in state fair contest, it would be interesting to run a three way test with lysosome vs Bactiless vs control on a white grape to see if bitter can be eliminated by being proactive and killing off wild LAB

 

[Raptor99]

I have been following this discussion with interest. I might need to do more careful monitoring of pH.

I found notes on a helpful presentation here: https://www.txwines.org/wp-content/uploads/2021/08/MLF-Management-ABotezatu.pdf. Some of the take aways for preventing unwanted MLF:
* Lower pH is better
* Lower fermentation/aging temperatures
* Higher alcohol levels
* Add 50-75 ppm SO2 pre-fermentation, depending on pH
* Maintain 0.8 ppm molecular SO2 post-fermentation
* Avoid leaving a lot of excess nutrients after alcoholic fermentation (feeds MLB)
* Consider using egg whites (contains Lysozyme)

These factors are mutually reinforcing, so they are most effective in combination.

 

[Hazelemere]

I have been following this discussion with interest. I might need to do more careful monitoring of pH.

I found notes on a helpful presentation here: https://www.txwines.org/wp-content/uploads/2021/08/MLF-Management-ABotezatu.pdf. Some of the take aways for preventing unwanted MLF:
* Lower pH is better
* Lower fermentation/aging temperatures
* Higher alcohol levels
* Add 50-75 ppm SO2 pre-fermentation, depending on pH
* Maintain 0.8 ppm molecular SO2 post-fermentation
* Avoid leaving a lot of excess nutrients after alcoholic fermentation (feeds MLB)
* Consider using egg whites (contains Lysozyme)

These factors are mutually reinforcing, so they are most effective in combination.

Don't add all of the sulphite at once. e.g. you can do 30 then 20 then 10 and 10 (3 rackings) and you should be fine. If you use bentonite then assume you are at 0 after bentonite.