Question:
Thanks! – Hide quoted text — Show quoted text – <snip I’d say, degas a small batch (by either heat or vacuum, just to drive off the dissolved CO2), cool it and add 2g/l of tartaric to see what it tastes like and where the pH moves to. If it still seems flat, add another gram/liter. I’d tend to go more by taste in this case than pH. After all, you’re planning to _drink_ it – not feed it to your pH meter! Sounds like a plan. I don’t have access to a microwave, so my next question is how hot and for how long? (To degas, that is.) Heat to boiling. Yair Margalit recommends a few seconds; I usually wait a minute or so. Use a measured volume of wine, and after the wine cools after boiling, bring it back up to the same volume (boiling tends to reduce the volume by around 10%, so if you don’t add back that much water, your TA reading will be 10% too high). Dave As for the taste of the wine, it’s not bad as it stands. I’m mostly concerned about longevity and the potential for spoilage. It will be interesting to do as you suggest and see how the taste of the sample changes, though. Thanks, K- —
Response:
Martin, Are you saying that at ph 8.2 that is when you get the color change to indicate the t/a? If this is correct then you should be able to get more accurate t/a readings using a good digital PH meter, by using them in conjunction with each other. I hope this is correct as I have problems just relying on my ability to recognize the point of color change. I really do not trust my t/a readings.
Frank: You’re right, that’s what I’m saying. I use a digital meter and phenalthaline (sp?) solution for my titrations. The color change occurs at pH 8.2. Try it on a white must. In addition to increased accuracy, using both also helps to show what we should be looking for in terms of color change. By the way, once you get to pH 7.0 go drop by drop, because changes from that point on occur very rapidly. Salud, Martin J. Crane
Response:
<snip Heat to boiling. Yair Margalit recommends a few seconds; I usually wait a minute or so. Use a measured volume of wine, and after the wine cools after boiling, bring it back up to the same volume (boiling tends to reduce the volume by around 10%, so if you don’t add back that much water, your TA reading will be 10% too high). —
Dave picked up a good tip here been tracking a mfc ,( one used at beginning of fermation, first time used this kind) after initial TA reading, my measuraments have been way off, driving me crazy! thought I lost the wine! before I done anything. you use distilled water to add back to sample, right? it doesn’t bother results, amount of water+wine? just factor that in? going to try this tommorrow! thanks
Response:
- Hide quoted text — Show quoted text – <snip Heat to boiling. Yair Margalit recommends a few seconds; I usually wait a minute or so. Use a measured volume of wine, and after the wine cools after boiling, bring it back up to the same volume (boiling tends to reduce the volume by around 10%, so if you don’t add back that much water, your TA reading will be 10% too high). — Dave picked up a good tip here been tracking a mfc ,( one used at beginning of fermation, first time used this kind) after initial TA reading, my measuraments have been way off, driving me crazy! thought I lost the wine! before I done anything. you use distilled water to add back to sample, right? it doesn’t bother results, amount of water+wine? just factor that in? going to try this tommorrow! thanks
This can also be done by boiling the water used for the TA titration, and adding your 5ml’s of wine while the water is still hot enough to ‘boil’ off the carbonic acid in the wine. An ice bath will quickly return the sample/water to room temp. latron clyde
Response:
- Hide quoted text — Show quoted text – <snip Heat to boiling. Yair Margalit recommends a few seconds; I usually wait a minute or so. Use a measured volume of wine, and after the wine cools after boiling, bring it back up to the same volume (boiling tends to reduce the volume by around 10%, so if you don’t add back that much water, your TA reading will be 10% too high). — Dave picked up a good tip here been tracking a mfc ,( one used at beginning of fermation, first time used this kind) after initial TA reading, my measuraments have been way off, driving me crazy! thought I lost the wine! before I done anything. you use distilled water to add back to sample, right? it doesn’t bother results, amount of water+wine? just factor that in? going to try this tommorrow! thanks
Hi, What’s an "mfc?" Anyway, no, don’t "factor in" the water you add, just add it. The idea is to measure (accurately) the volume of juice you boil, boil away 10% or so, then add water to get back to your original volume. No factoring necessary. Dave
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Dave, alittle off this thread, but as I think of it, is your winery commercial? If so, how may I get some? Jim L.
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Dave, alittle off this thread, but as I think of it, is your winery commercial? If so, how may I get some? Jim L.
Hi Jim, I make wine at home, but I’m also the assistant winemaker at one of the Finger Lakes (NY) wineries, King Ferry Winery. Whether or not our stuff would be available in your state depends on what state you’re in. Thanks for asking! Dave
Response:
– Hide quoted text — Show quoted text – <snip Heat to boiling. Yair Margalit recommends a few seconds; I usually wait a minute or so. Use a measured volume of wine, and after the wine cools after boiling, bring it back up to the same volume (boiling tends to reduce the volume by around 10%, so if you don’t add back that much water, your TA reading will be 10% too high). — Dave picked up a good tip here been tracking a mfc ,( one used at beginning of fermation, first time used this kind) after initial TA reading, my measuraments have been way off, driving me crazy! thought I lost the wine! before I done anything. you use distilled water to add back to sample, right? it doesn’t bother results, amount of water+wine? just factor that in? going to try this tommorrow! thanks Hi, What’s an "mfc?" Anyway, no, don’t "factor in" the water you add, just add it. The idea is to measure (accurately) the volume of juice you boil, boil away 10% or so, then add water to get back to your original volume. No factoring necessary. Dave
Thanks Dave! Mfc is melolatic fermentation culture or mlf sorry! will try it again. can I use more distilled water, using a ph meter, to make it easier to read. distilled water doesn’t effect the result? thanks phil please remove . from e-mail adress to stop spaming!
Response:
Seems to me that in measuring T/A there is no need to add back the water. You are measuring the amount of acid present and boiling only causes water to evaporate, not the acid. Consequently, the amount of water is material only to the depth of color for identification purposes and has no effect on the color change point. Whether you leave it as is or add another 10 or 20 cc’s of water, the end result will be the same. Bob B
Response:
Seems to me that in measuring T/A there is no need to add back the water. You are measuring the amount of acid present and boiling only causes water to evaporate, not the acid. Consequently, the amount of water is material only to the depth of color for identification purposes and has no effect on the color change point. Whether you leave it as is or add another 10 or 20 cc’s of water, the end result will be the same. Bob B
Depends, I think. If you’re takingan aliquot of the wine, you want that to be of the proper concentration (i.e., if you boild the wine to 90% of its original volume and don’t re-dilute it and take an aliquot, you’re taking ~10% more acids in your aliquot than you otherwise would). On the other hand, if you do what was suggested earlier, and take an aliquot and dump it into boiling water, then if 10% boils off, you don’t care. Dave —
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David I’m not a chemist (and you are) but if all you have driven off is water then adding water back does not make any difference to the total amount of acid (in g/l) present. That amount of acid is still there. Providing your original sample size is used in your calculation if you dilute or concentrate it, it won’t make any difference in the calculation. You will still have titrated the amount of acid present in the original sample. Am I right or am I as confused as I think I am? What might be of more concern is that if the total volume reduces by 10% then it won’t just be water that has been lost but volatile acids also. That means the figure acheived will be more representative of fixed acidity rather than total acidity (which is all titratable acids excluding CO2 (I think). :-^~ Little Podge – Hide quoted text — Show quoted text – Seems to me that in measuring T/A there is no need to add back the water. You are measuring the amount of acid present and boiling only causes water to evaporate, not the acid. Consequently, the amount of water is material only to the depth of color for identification purposes and has no effect on the color change point. Whether you leave it as is or add another 10 or 20 cc’s of water, the end result will be the same. Bob B Depends, I think. If you’re takingan aliquot of the wine, you want that to be of the proper concentration (i.e., if you boild the wine to 90% of its original volume and don’t re-dilute it and take an aliquot, you’re taking ~10% more acids in your aliquot than you otherwise would). On the other hand, if you do what was suggested earlier, and take an aliquot and dump it into boiling water, then if 10% boils off, you don’t care. Dave —
**** Dave Breeden
Response:
David I’m not a chemist (and you are) but if all you have driven off is water then adding water back does not make any difference to the total amount of acid (in g/l) present. That amount of acid is still there. Providing your original sample size is used in your calculation if you dilute or concentrate it, it won’t make any difference in the calculation. You will still have titrated the amount of acid present in the original sample. Am I right or am I as confused as I think I am? What might be of more concern is that if the total volume reduces by 10% then it won’t just be water that has been lost but volatile acids also. That means the figure acheived will be more representative of fixed acidity rather than total acidity (which is all titratable acids excluding CO2 (I think). :-^~ Little Podge
It does matter though. Let’s take an example: I’ve got 100 mL of wine that’s 10 g/L (high, but not impossible, and makes for easier math). If I boil away 10 mL of water, than I’ve got 1 g of acid in 90 mL of water, or ~ 1.1 g/100 mL, or 11 g/L. So if I boil it and reduce it by 10% without re-diluting it, I’m increasing my TA by about 10%. I’m pretty sure that we agree about this, and are just talking past each other at this point. And yes, you would be driving off not only CO2 (which you want) but volatile acidity as well, but my assumption is that, unless I can taste otherwise, VA is so small a part of TA that it doesn’t matter. The only real way to test for VA as a part of TA that I’d really trust is HPLC, which is lovely and relatively easy, but has VERY high initial costs. Dave
Response:
Dave I think so too. My point is that you take the value from titrating that 90 ml sample but express it as the amount of acid in a 100 ml sample you will still get the right result. You don’t physically have to add the water back to the sample to do the titration properly. I’m digging myself a deeper hole here aren’t I? If a wine has a VA at anything up to about 0.7 g/l acetic then I reckon most people would not recognise it as being volatile but that equates to 0.875 g/l tartaric and that could represent a pretty good slice of someones TA value. However, most of us are used to seeing TA rather than FA values so I guess we all take a similar approach and don’t worry. I like enzymatic determination of acetic myself. The cost per test is higher than HPLC but capital outlay is lower. Little Podge matter though. Let’s take an example: I’ve got 100 mL of – Hide quoted text — Show quoted text – wine that’s 10 g/L (high, but not impossible, and makes for easier math). If I boil away 10 mL of water, than I’ve got 1 g of acid in 90 mL of water, or ~ 1.1 g/100 mL, or 11 g/L. So if I boil it and reduce it by 10% without re-diluting it, I’m increasing my TA by about 10%. I’m pretty sure that we agree about this, and are just talking past each other at this point. unless I can taste otherwise, VA is so small a part of TA that it doesn’t matter. The only real way to test for VA as a part of TA that I’d really trust is HPLC, which is lovely and relatively easy, but has VERY high initial costs. Dave
**** Dave Breeden
Response:
Martin, Are you saying that at ph 8.2 that is when you get the color change to indicate the t/a? If this is correct then you should be able to get more accurate t/a readings using a good digital PH meter, by using them in conjunction with each other. I hope this is correct as I have problems just relying on my ability to recognize the point of color change. I really do not trust my t/a readings. — Frank Cerrone
– Hide quoted text — Show quoted text – I am currently making a Zin from fruit, and have been frustrated with trying to use test strips to measure pH and color indicators to measure TA. I finally broke down and bought a pH meter. The measurements I got surprised me. My Zin, which has been dry for about 1 1/2 weeks now, has a pH of 4.2 and a TA of .55%! I was floored by this, as the supplier of my grapes had indicated the pH should be in the 3.6 neighborhood. What’s worse, M/L is underway and as I understand it this will lower the acidity of the wine even further. Question: what is the best type of acid for me to be adding in this situation, given that I need a *big* reduction in pH without shooting the TA through the roof? I assume that the answer is tartaric, but would like some verification from the ng. Thanks, Kevin Before I made any additions to the wine, I’d check to make sure that the pH meter is properly calibrated, especially if the wine tastes about right to you without any adjustments. If you’re not absolutely sure, you could take a sample to a high school or community college chemistry lab for comparison purposes. Your TA is in the neighborhood — did you use your pH meter to titrate or did you rely on color change? Try titrating again using both the meter and the phenothaline solution. Color change should occur at pH 8.2. If it doesn’t, the meter may be out of whack. Also, since you’re measuring shortly after fermentation, first boil the sample in a microwave for a short time to get the residuaI CO2 out. That can mess up your readings too. I found out the hard way that your measurements are only as good as your instruments and your technique. Salud, Martin J. Crane
Response:
This is correct. I have already tried it on a couple of wines I’m making, and the difference in accuracy is phenomenal! K- – Hide quoted text — Show quoted text – Martin, Are you saying that at ph 8.2 that is when you get the color change to indicate the t/a? If this is correct then you should be able to get more accurate t/a readings using a good digital PH meter, by using them in conjunction with each other. I hope this is correct as I have problems just relying on my ability to recognize the point of color change. I really do not trust my t/a readings. — Frank Cerrone I am currently making a Zin from fruit, and have been frustrated with trying to use test strips to measure pH and color indicators to measure TA. I finally broke down and bought a pH meter. The measurements I got surprised me. My Zin, which has been dry for about 1 1/2 weeks now, has a pH of 4.2 and a TA of .55%! I was floored by this, as the supplier of my grapes had indicated the pH should be in the 3.6 neighborhood. What’s worse, M/L is underway and as I understand it this will lower the acidity of the wine even further. Question: what is the best type of acid for me to be adding in this situation, given that I need a *big* reduction in pH without shooting the TA through the roof? I assume that the answer is tartaric, but would like some verification from the ng. Thanks, Kevin Before I made any additions to the wine, I’d check to make sure that the pH meter is properly calibrated, especially if the wine tastes about right to you without any adjustments. If you’re not absolutely sure, you could take a sample to a high school or community college chemistry lab for comparison purposes. Your TA is in the neighborhood — did you use your pH meter to titrate or did you rely on color change? Try titrating again using both the meter and the phenothaline solution. Color change should occur at pH 8.2. If it doesn’t, the meter may be out of whack. Also, since you’re measuring shortly after fermentation, first boil the sample in a microwave for a short time to get the residuaI CO2 out. That can mess up your readings too. I found out the hard way that your measurements are only as good as your instruments and your technique. Salud, Martin J. Crane
Response:
I am currently making a Zin from fruit, and have been frustrated with trying to use test strips to measure pH and color indicators to measure TA. I finally broke down and bought a pH meter. The measurements I got surprised me. My Zin, which has been dry for about 1 1/2 weeks now, has a pH of 4.2 and a TA of .55%! I was floored by this, as the supplier of my grapes had indicated the pH should be in the 3.6 neighborhood. What’s worse, M/L is underway and as I understand it this will lower the acidity of the wine even further. Question: what is the best type of acid for me to be adding in this situation, given that I need a *big* reduction in pH without shooting the TA through the roof? I assume that the answer is tartaric, but would like some verification from the ng. Thanks, Kevin
Response:
I am currently making a Zin from fruit, and have been frustrated with trying to use test strips to measure pH and color indicators to measure TA.
Forget test strips. They are _useless_ for winemaking – even white winemaking. The resolution is only to 0.3 pH units, and that’s ‘way too broad a range. My Zin, which has been dry for about 1 1/2 weeks now, has a pH of 4.2 and a TA of .55%! I was floored by this, as the supplier of my grapes had indicated the pH should be in the 3.6 neighborhood. What’s worse, M/L is underway and as I understand it this will lower the acidity of the wine even further.
You’re going to have to add tartaric to this wine, or it’ll be flatter than a pancake, and the spoilage organisms will be uncontrollable – unless you add salad-bar size doses of sulfite, which I don’t recommend. Don’t overreact, though, or the wine will taste awfully "doctored". I’d say, degas a small batch (by either heat or vacuum, just to drive off the dissolved CO2), cool it and add 2g/l of tartaric to see what it tastes like and where the pH moves to. If it still seems flat, add another gram/liter. I’d tend to go more by taste in this case than pH. After all, you’re planning to _drink_ it – not feed it to your pH meter! Tom
Response:
- Hide quoted text — Show quoted text – I am currently making a Zin from fruit, and have been frustrated with trying to use test strips to measure pH and color indicators to measure TA. I finally broke down and bought a pH meter. The measurements I got surprised me. My Zin, which has been dry for about 1 1/2 weeks now, has a pH of 4.2 and a TA of .55%! I was floored by this, as the supplier of my grapes had indicated the pH should be in the 3.6 neighborhood. What’s worse, M/L is underway and as I understand it this will lower the acidity of the wine even further. Question: what is the best type of acid for me to be adding in this situation, given that I need a *big* reduction in pH without shooting the TA through the roof? I assume that the answer is tartaric, but would like some verification from the ng. Thanks, Kevin
Hi Kevin, It would have been best for you to buy the meter earlier. I know that doesn’t do you much good now, but for next time, you’ll want to adjust the pH before adding yeast. Fermentation can, and usually does, raise the pH level of the wine. Tartrate formation can raise the pH of the wine if the starting point is above 3.65. However, if you keep the pH comfortably below this (3.4 range for reds. 3.3 for whites), the pH will tend to drop from tartrate formation which, incidentally begins during fermentation, from the increase in alcohol. It is also generally excepted that acids added prior to fermentation end up softer on the pallet. I’ve had many (high potassium) wines that would hold or even lower pH during fermentation. But what to do now. Adjustments prior to cold stablilizing(CS) should be tartaric, and you’ll do no good to the pH situation if you don’t get it below 3.65 for the reasons stated above. Starting at 4.2, this may send your TA off the charts. (Note that TA can drop only a couple of points from CS) With a small volume of wine, I would tend to just take my chances and drink the stuff early; Have a party. The main reason to monitor pH is for longevity. Contamination becomes more likely and color will be lost sooner. But if it has too high of a TA, it may sit in your cellar for a very, very long time. One last thing, your subject line has confused me (not that that’s a difficult task), but your pH, as reported, is high; not ‘VERY low’. Also TA is only low if it _taste_ low. latron clyde
Response:
<snip I’d say, degas a small batch (by either heat or vacuum, just to drive off the dissolved CO2), cool it and add 2g/l of tartaric to see what it tastes like and where the pH moves to. If it still seems flat, add another gram/liter. I’d tend to go more by taste in this case than pH. After all, you’re planning to _drink_ it – not feed it to your pH meter! Sounds like a plan. I don’t have access to a microwave, so my next question is how hot and for how long? (To degas, that is.)
Heat to boiling. Yair Margalit recommends a few seconds; I usually wait a minute or so. Use a measured volume of wine, and after the wine cools after boiling, bring it back up to the same volume (boiling tends to reduce the volume by around 10%, so if you don’t add back that much water, your TA reading will be 10% too high). Dave As for the taste of the wine, it’s not bad as it stands. I’m mostly concerned about longevity and the potential for spoilage. It will be interesting to do as you suggest and see how the taste of the sample changes, though. Thanks, K-
–
Response:
Hi Kevin, <snip Also TA is only low if it _taste_ low. latron clyde
Clyde, Thanks for the advice. I’m certainly learning the value of having good tools at hand when you want to do a good job of winemaking! Based on your advice and that of others, I will add acid to a sample and see what happens to the taste as well as pH and TA. After all, I’d rather have a drinkable wine with little shelf life than an undrinkable one that will be around forever! K-
Response:
<snip I’d say, degas a small batch (by either heat or vacuum, just to drive off the dissolved CO2), cool it and add 2g/l of tartaric to see what it tastes like and where the pH moves to. If it still seems flat, add another gram/liter. I’d tend to go more by taste in this case than pH. After all, you’re planning to _drink_ it – not feed it to your pH meter!
Sounds like a plan. I don’t have access to a microwave, so my next question is how hot and for how long? (To degas, that is.) As for the taste of the wine, it’s not bad as it stands. I’m mostly concerned about longevity and the potential for spoilage. It will be interesting to do as you suggest and see how the taste of the sample changes, though. Thanks, K-
Response:
- Hide quoted text — Show quoted text -I am currently making a Zin from fruit, and have been frustrated with trying to use test strips to measure pH and color indicators to measure TA. I finally broke down and bought a pH meter. The measurements I got surprised me. My Zin, which has been dry for about 1 1/2 weeks now, has a pH of 4.2 and a TA of .55%! I was floored by this, as the supplier of my grapes had indicated the pH should be in the 3.6 neighborhood. What’s worse, M/L is underway and as I understand it this will lower the acidity of the wine even further. Question: what is the best type of acid for me to be adding in this situation, given that I need a *big* reduction in pH without shooting the TA through the roof? I assume that the answer is tartaric, but would like some verification from the ng. Thanks, Kevin
Before I made any additions to the wine, I’d check to make sure that the pH meter is properly calibrated, especially if the wine tastes about right to you without any adjustments. If you’re not absolutely sure, you could take a sample to a high school or community college chemistry lab for comparison purposes. Your TA is in the neighborhood — did you use your pH meter to titrate or did you rely on color change? Try titrating again using both the meter and the phenothaline solution. Color change should occur at pH 8.2. If it doesn’t, the meter may be out of whack. Also, since you’re measuring shortly after fermentation, first boil the sample in a microwave for a short time to get the residuaI CO2 out. That can mess up your readings too. I found out the hard way that your measurements are only as good as your instruments and your technique. Salud, Martin J. Crane
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