Blackberry Ph help needed

[toddrod]

So today I was finally able to check my blackberry must's Ph with my digital Ph meter. I calibrated the meter as directed and then checked the pure juice (that has been fermenting for 3 days on the pulp). The reading was 3.29. Now I split the must (after straining out the pulp) up into 3 gal each and added 3 gallons of sugar water with a SG 1.090 to each batch. This will work out to 4lbs/gal of fruit. I checked the Ph again and it is now reading 3.15 after I diluted it. I rechecked the reading of my meter with control solutions and it was dead on.

So, my question is how can the Ph go down after dilution. From my chemistry class in college it should have come up, esp when the sugar water Ph was 5.2. I am so confused right now. I am using 71B as the yeast.

 

[BernardSmith]

Several questions: How confident are you that the pH of the chemicals you use to calibrate your pH meter are reliable? How confident are you that the first pH reading you took was reliable? How confident are you that the terminal was clean when you checked the pH a second time? Did you strain the pulp before or after taking the pH reading? How long did you wait after adding the sugar before you took the reading? What impact does fermentation have on the pH?

 

[toddrod]

1. Fresh opened pack of Hanna control solution
2. Brand new, out the box, tester that was calibrated
3. I rinsed it very well under running water. Tested the juice and then tested again with control solutions
4. Pulp was strained out of the juice before testing
5. 4 days
6. I have no idea.

 

[ibglowin]

pH usually gets lowered after fermentation.

You can't get an accurate pH on ANY solution if it is loaded with a gas. In this instance your loaded with CO2. You have to either wait till its finished and degassed or try and degas the sample you pull. Not always easy.

At this point don't panic. Just let things finish out and then check your pH once you are sure its finished and fully degassed. You can make adjustments after things have finished and settled out.

 

[gordini]

Yes, doing a pH reading during ferment is not accurate. If it is absolutely necessary, you need to thoroughly degass the sample. A vacuum pump is needed. A drop of 0.14 at this stage is not alarming. I would be more worried it it went the other way. Clean and recalibrate the pH metre and then use it on a sample of known pH. Not having confidence in your equipment is frustrating.

 

[Turock]

It's important for you to understand that PH adjustments need to be made to the must before you adjust the brix and add the culture. Get the pectic enzyme in on the first day. On the second day, stir the must very well. The pectic enzyme will have broken down some of the fruit so that your PH reading of the fruit is more accurate. Adjust according to the results of the PH. If PH is too high,add acid. If too low, add calcium carbonate. Don't adjust PH with water. It will only dilute what would otherwise be a very good wine. If you follow this procedure on all your musts, your wines will be much improved. Adjustments at the primary are always easier and your wines come out much more balanced.