Potassium Bicarbonate/cold stabilization basic questions

Discussion in 'Wine Making from Grapes' started by NorCal, Feb 3, 2019.

Wine Making Forum

Help Support Winemaking Talk by donating:

  1. Feb 3, 2019 #1

    NorCal

    NorCal

    NorCal

    Super Moderator Super Moderator

    Joined:
    Apr 18, 2014
    Messages:
    2,581
    Likes Received:
    2,327
    Gender:
    Male
    Location:
    Placer County, CA
    For the first time in my wine making career, I am dealing with a wine that is too tart to my liking. Normally I’m struggling with 4.0, flabby pH wines, but this year’s Viognier is tart to the taste. The flavor is good, but the finish leaves my tongue sweating like a faucet. Tastes like a light, fruity Chardonnay with a Sauvignon Blanc finish.

    @4score and I crushed 1,000 pounds, initial brix were 23.7, pH 3.5, went through mlf. We did not measure TA, which is what I’m assuming what I’m trying to address now. The Potasium Bicarbonate was ordered at noon yesterday and is out for delivery now (on Sunday!). Amazon is pretty amazing.

    I've tried a sample with backsweeten (.6 g/l), which is currently in the fridge to try later today and perhaps avoid this altogether. I’m a little concerned about in bottle refermentation if I went this route.

    I will be adjusting solely to improve the flavor and really don’t care about the pH/TA numbers. I’ll be doing bench trials.

    Questions
    How many g/l should I adjust at a time, in order to have a noticeable impact?

    Is the acid/base interaction immediate or does the wine need to be cold stabilized for the compound to fall out?

    Once I find the minimum amount to add to my batch, how long and at what temperature is necessary to cold stabilize the wine?

    Any other helpful hints?
     
    Ajmassa5983 likes this.
  2. Feb 3, 2019 #2

    mainshipfred

    mainshipfred

    mainshipfred

    Junior Member WMT Supporter

    Joined:
    Feb 25, 2017
    Messages:
    2,800
    Likes Received:
    1,646
    I can't help with the bicarbonite but in regard to cold stabilization aren't you hovering on the increased/decreased threshold for the acid adjustment being at 3.5 ph?
     
    NorCal likes this.
  3. Feb 3, 2019 #3

    Ajmassa5983

    Ajmassa5983

    Ajmassa5983

    Just a Guy

    Joined:
    Oct 26, 2016
    Messages:
    3,068
    Likes Received:
    2,327
    NorCal I’m am doing this exact thing right now! Also using potassium bicarbonate. And this will be my first time removing acid from wine using antacid chems.
    My current numbers are theoretically good so this one is also being done by taste. (I added tartaric from 3.9 to 3.6 last year but was too much)
    I read both potassium carb and bicarbonate require cold stabilization. The carbonate has chemical components that can accept two protons H+ whereas bicarb already has one so can only accept one——- which means that carbonate is more reactant and thus more sensitive to jacking up the ph in the process. Which is why I decided on using bicarbonate.
    I copy and pasted this in my notes from an old WMT thread but I never saved the link

    (This guide is also interchangeable with potassium bicarbonate it said)
    “As with tartaric acid, for the purpose of testing for the proper additions of potassium carbonate, make a 5% solution. Put one litre of wine into a refrigerator and chill to about -3 or -4°C. Set up a few glasses with 100 ml of the chilled wine. Using one as a control, add 1, 2, 3, etc, mls. of the solution which will be the equivalent of 0.5, 1.0, 1.5, etc, g/l. Refrigerate for two hours or so stirring regularly - 7 or 8 times. Let the samples warm up to cellar temperature and taste to determine the amount to add to the batch. It is necessary to taste the wine after the potassium carbonate has been added to the glasses in order to determine whether there is a resulting flabby taste. I have found that some wines, particularly aromatic wines lose their crispness when potassium carbonate is used even in very small amounts".

    This is the bench trial test I am currently preparing for right now.
     
    NorCal likes this.
  4. Feb 3, 2019 #4

    NorCal

    NorCal

    NorCal

    Super Moderator Super Moderator

    Joined:
    Apr 18, 2014
    Messages:
    2,581
    Likes Received:
    2,327
    Gender:
    Male
    Location:
    Placer County, CA
    If the pH goes up and TA goes down and the taste improves, that works for me.
     
    Ajmassa5983 likes this.
  5. Feb 3, 2019 #5

    Ajmassa5983

    Ajmassa5983

    Ajmassa5983

    Just a Guy

    Joined:
    Oct 26, 2016
    Messages:
    3,068
    Likes Received:
    2,327
    FWIW I’m not making a 5% solution. I just calculated the additions in 1/2g/L increments based on 100mL samples. That comes out to be .033g of kbicarb.
    Also I should let it be known I have no idea what I’m doing. Totally wingin it here. And regurgitating info I found that I decided to use. I am suggesting nothing. And I’m open to any insight/advice/recommendations that anyone is willing to offer. *shoulda done bench trials the first time around. The wine is 20 gal of a super Tuscan blend from 2017 grapes. And sweetening is not an option. Already at 1.000sg
    IMG_0187.JPG
     
  6. Feb 3, 2019 #6

    Ajmassa5983

    Ajmassa5983

    Ajmassa5983

    Just a Guy

    Joined:
    Oct 26, 2016
    Messages:
    3,068
    Likes Received:
    2,327
    I can’t speak for NorCal but my wines ph is 3.6. My meter reads one decimal point. So whichever direction it moves is up to the wine gods. (Gut tells me under 3.65 by watching how the meter dials in before stopping). My thought is that whichever way it moves will not be drastic enough to cause concern.
    As far as after trial, dosing and CS, I don’t have many options. Will transfer into carboys and place into milkcrates, wrapping something to insulate and sticking in the garage for I’m guessing at least a month(?) I hope to maintain <40° (Varying info online for this)
    And I found that link I mentioned. https://www.winemakingtalk.com/thre...otassium-bicarbonate-post-fermentation.56253/
     
    jsbeckton likes this.
  7. Feb 3, 2019 #7

    stickman

    stickman

    stickman

    Veteran Winemaker

    Joined:
    Jun 16, 2014
    Messages:
    1,120
    Likes Received:
    837
    @NorCal did you try chill proofing a sample of the wine as is? If not, it may be worth a try to see how it tastes. Try the freeze overnight - thaw - decant - procedure. If you do end up adding potassium bicarbonate, it would be best to get a sample and raise the pH to 3.6 and then do the freeze thaw overnight procedure and then taste. The reason for this is that the greatest acid precipitation will occur at 3.6 pH.

    The neutralization part of the reaction is fast, but the tartrate precipitation is slow. If you add potassium bicarbonate and taste during a bench trial, you'll only be tasting the drop in acidity due to the neutralization, but the potassium bitartrate that has not yet precipitated will still be contributing to the acid taste.

    After adding the potassium bicarbonate, the wine will be saturated with carbon dioxide, therefore degassing or sparging with nitrogen is recommended to strip the wine of the majority of the CO2, otherwise, there will a significant increase in perceived acidity due to the CO2. The saturation concentration of carbon dioxide at 50°F is about 2,000 mg/L, or the equivalent of 3.6 g/L T.A. as tartaric acid.
     
    Rice_Guy and Ajmassa5983 like this.
  8. Feb 3, 2019 #8

    Ajmassa5983

    Ajmassa5983

    Ajmassa5983

    Just a Guy

    Joined:
    Oct 26, 2016
    Messages:
    3,068
    Likes Received:
    2,327
    That bench trial I reposted which says to chill the wine first, then make additions followed by 2 hours of chilling and stirring then allowing to warm up to cellar temps before tasting —- I’m assuming that is to mimic the CS to a degree.
    Does that sound plausible? If not, what is your opinion of how much more effect precipitation has on the taste after neutralization?
    *sorry for the piggyback NorCal. I was about to start similar thread when I saw your post.
     
  9. Feb 3, 2019 #9

    NorCal

    NorCal

    NorCal

    Super Moderator Super Moderator

    Joined:
    Apr 18, 2014
    Messages:
    2,581
    Likes Received:
    2,327
    Gender:
    Male
    Location:
    Placer County, CA
    No worries, I welcome the collaboration.
     
    Ajmassa5983 likes this.
  10. Feb 3, 2019 #10

    stickman

    stickman

    stickman

    Veteran Winemaker

    Joined:
    Jun 16, 2014
    Messages:
    1,120
    Likes Received:
    837
    I think one way or another some attempt needs to be made to precipitate the tartrates before a final tasting, I can't speak for the other CS procedure, but the overnight freeze thaw is about as good as can be done without chilling for weeks etc. The cold stabilization accounts for about 25% to 50% of the calculated acid reduction.
     
    NorCal and Ajmassa5983 like this.
  11. Feb 4, 2019 #11

    sour_grapes

    sour_grapes

    sour_grapes

    Victim of the Invasion of the Avatar Snatchers

    Joined:
    Sep 19, 2013
    Messages:
    9,445
    Likes Received:
    6,928
    Sounds like @salcoco to me!
     
  12. Feb 4, 2019 #12

    Ajmassa5983

    Ajmassa5983

    Ajmassa5983

    Just a Guy

    Joined:
    Oct 26, 2016
    Messages:
    3,068
    Likes Received:
    2,327
    I found it and posted the link a few posts back. Was from member @Tnuscan. And the bit about the H+ protons was paraphrased from @ibglowin lending to my kbicarb decision.
    I kinda took a little bit from everyone, using @NorCal’s thread and @Stickman’s deep freeze suggestion too. Group effort lol. Thanks to all for the help.
    I’ve got (x4) 100mL trial samples prepared and in the freezer now.
    1. Control
    2. .5 g/L using .03g Kbicarb
    3. 1 g/L using .06g Kbicarb
    4. 1.5 g/L using .1g Kbicarb

    I’ll bail out now NorCal. Threads all yours!
    IMG_0192.JPG
     
    stickman likes this.
  13. Feb 4, 2019 #13

    NorCal

    NorCal

    NorCal

    Super Moderator Super Moderator

    Joined:
    Apr 18, 2014
    Messages:
    2,581
    Likes Received:
    2,327
    Gender:
    Male
    Location:
    Placer County, CA
    @Ajmassa5983, don’t you dare leave me now. I’m preparing my samples as we speak. However, the best I can do, due to business travels is prepare the samples tonight and put in the fridge for 24 hours. I’ll then do my tasting, knowing that even more acids could drop out with time.
     
    stickman and Ajmassa5983 like this.
  14. Feb 4, 2019 #14

    Ajmassa5983

    Ajmassa5983

    Ajmassa5983

    Just a Guy

    Joined:
    Oct 26, 2016
    Messages:
    3,068
    Likes Received:
    2,327
    Sounds good. Maybe my results will lend some more insight for you then since I’m freezing.
    For reference this was a 2017 Tuscan field blend that had a high ph. Adjusted with tartaric. Numbers good. Taste not so much. Been aging and procrastinating on this acid removal for a while now.
    Ph 3.6. Then read 3.5 after shaking the crap outta it. TA 6.6.
    Gonna thaw, check levels and taste either tomorrow or Tuesday.
     
  15. Feb 4, 2019 #15

    NorCal

    NorCal

    NorCal

    Super Moderator Super Moderator

    Joined:
    Apr 18, 2014
    Messages:
    2,581
    Likes Received:
    2,327
    Gender:
    Male
    Location:
    Placer County, CA
    200 ml samples are in the fridge.

    I realized that our numbers mean different things. I used the amount of bicarbonate added vs. calculated g/l reduction in TA.

    I made a solution with .6 grams of bicarbonate for the samples as follows:
    0 - 0 grams
    0.5 - .1 gram
    1.0 - .2 grams
    1.5 - .3 grams

    Not sure why I was expecting more of a CO2 reaction.

    86E4C864-2B34-4176-B4CE-30E1CFCBBBEC.jpeg
     
    Last edited: Feb 5, 2019
    Ajmassa5983 likes this.
  16. Feb 4, 2019 #16

    Ajmassa5983

    Ajmassa5983

    Ajmassa5983

    Just a Guy

    Joined:
    Oct 26, 2016
    Messages:
    3,068
    Likes Received:
    2,327
    Took a min to figure this one. I used fermcalc for the rate .66 g/L addition to remove 1g/L of acid while you used .1g/L rate. I moved in .33g increments compared to your .5g increments.
    Kinda confusing with different sample size and rates but still same basically. Biggest difference is our 1.5g/L removal sample—yours with .15g/L to my .10g/L. Just more data for us. A wide range and a narrow range.
    Plus I’m throwing projections out the window anyway. This ones all about taste
     
  17. Feb 4, 2019 #17

    montanarick

    montanarick

    montanarick

    Member

    Joined:
    May 15, 2015
    Messages:
    67
    Likes Received:
    32
    Location:
    Montana
    potassium bicarbonate will increase Ph. Since it's already at 3.5 not sure why you'd want to do that?
     
  18. Feb 4, 2019 #18

    NorCal

    NorCal

    NorCal

    Super Moderator Super Moderator

    Joined:
    Apr 18, 2014
    Messages:
    2,581
    Likes Received:
    2,327
    Gender:
    Male
    Location:
    Placer County, CA
    If it is a choice between a wine with good numbers but doesn't taste good or a wine that tastes good with numbers that aren't as good, I'll pick the latter.
     
    stickman and cmason1957 like this.
  19. Feb 4, 2019 #19

    Ajmassa5983

    Ajmassa5983

    Ajmassa5983

    Just a Guy

    Joined:
    Oct 26, 2016
    Messages:
    3,068
    Likes Received:
    2,327
    There’s a weird chemical anomaly when using potassium bi/carbonate combined with cold stabilizing. Regardless of lowering TA the ph will move down if under 3.65 and up if above.
    But for me- acid was added to ideal numbers. But was too much for the taste. So as long as numbers stay in relatively safe ranges after removal the most important thing is to dial in the taste
     
  20. Feb 4, 2019 #20

    Ajmassa5983

    Ajmassa5983

    Ajmassa5983

    Just a Guy

    Joined:
    Oct 26, 2016
    Messages:
    3,068
    Likes Received:
    2,327
    Right now I’m thawing samples and will freeze again in the morning and remove in the afternoon.
    I assume length of freeze time makes no difference but not sure. Is there any acid activity happening while the wine is frozen or is it simply the ‘freezing/thawing’ process that mimics CS?
     

Share This Page