PH and Sulfites - Is there a direct connection?

[rickbw]

My son and I have started to embark on a winemaking mission. We have dove right in and have 4 batches started. Two reds and two whites. We bought the wine kits from our local homebrew / wine store and decided to buy the best kits we could get our hands on (Selection International and Grand Cru). Things are going well and we have read tons of info in these forums and read several publications.

My question is in regards to measuring and adding sulfites. I have watched the following video (found on this forum);

[ame]http://www.youtube.com/watch?v=-4FxcsjlWvQ&feature=channel&list=UL[/ame]

The video seems to state that you can calculate the amount of sulfites required by measuring the PH. Is this true? If so, it seems a much better way than paying $250 for a sulfite tester or attempting to use strips which are not reliable (especially on reds).

Any help would be appreciated - Thx.

 

[BobF]

Yes, there is a direct correlation. Measuring pH tells you how much free SO2 you need, but it doesn't tell you how much you already have.

I don't do many kits, so I'll let an experienced kit maker weigh in on measuring requirements for kits, or if the kit directions suffice.

 

[ibglowin]

Like Bob said yes, there is a direct correlation with pH and the AMOUNT of Sulfites needed in a wine to properly protect the wine from oxidation. The lower the pH the less amount of Sulfites are needed to protect it. You still need a way to measure sulfites if you don't just want to guess all the time if your wine needs more or not before bottling.

 

[rickbw]

So Mike, from your answer I'm assuming it is a legitemate process to check PH and then add proper amount of sulfite per the video (in other words you do not need an actual sulfite tester)?

 

[ibglowin]

Without a sulfite test of some sort you have no way of knowing how much sulfite is in the wine. The pH tells you how much is needed only. What your not picking up is that it is the amount of "free" SO2 that is important, there are two types. Free and Bound. Bound SO2 has reacted with O2 and has done its job. It is no longer available to protect the wine. You are measuring Free SO2 with a test. When you dump in your initial dose of Sulfite a whole bunch is going to immediately react with O2 and therefore not be available any more to protect the wine. This is why you need to test the wine. As you bulk age free SO2 levels will drop and you need to get the level back to where it needs to be just before bottling.