it can be anywhere from 3.2 to 3.6 depending on starting PH and type of wine. most likely in error if right after fermentation as carbolic acid and co2 can cause a mis reading. wait util wine has stopped fermenting and clear before recording any type of ph reading.
The critical thing about a pH reading when a wine is aging is to determine how much SO2 to add to inhibit oxidation. I am not sure that there is an expected or desired pH after fermentation has ended. When you pitch the yeast too low a pH (below about 3.2 ) can inhibit or stall fermentation but if the wine is aging I think pH can be whatever it is.
the ph strips are not very accurate. I would purchase a hydrometer and measure your wine to see if fermentation is complete. once complete, taste tests will tell you more than numbers as to the adequacy of your wine for drinking. ph is a value to use for kmeta dosages, but I usually follow the practice of 1/4 tsp of powder per 5 gallons and that will suffice.
I agree with salcoco. I wonder if your question is less about pH and more about TA - and TA is all about taste and not the strength of the acids in the wine. You CAN use a pH meter to check the TA. pH and TA are not the same. Your taste buds are the best tool but the point at which the color changes when you use a TA test kit is always at the pH of 8.2 - and measuring the pH is far easier (IMO) than identifying the exact point at which the color in your test vial changes when you are titrating the reagent sodium hydroxide
Yes. Take a sample and shake the s++t out of it you get no more bubbles. Co2 gas can throw off the reading. Then test again and see what you've got. If your pH is really that high you should add some acid and bring it down to the 3.2-3.6 range. Not just for taste but to protect the wine also. Either acid blend or tartaric acid seems to be a favorite here. Good luck!
ps. you can get inexpensive pH meters off Ebay for $20. There are better ones out there (and more expensive) but even a cheap meter (calibrated) is much better than test strips. Mine has served me well.
Not exactly sure what that stuff is, but calcium carbonate is used to raise pH (less acidic) pre-ferment. What you need to do is lower the pH (more acidic) with either an acid blend or like I mentioned earlier, most here prefer tartaric acid. I would try to get the wine below 3.7 to protect it if nothing else.