Checking the PH of a new batch

It has to be between 3 - 4 for a perfect sauce. Anything above 4 and it wont be shelf stable and could carry on fermenting leading to exploding bottles. Below 3 and the sauce will be too acidic and wont taste fantastic, it'll be too sharp and vinegary. Around 3.5 is the ideal. This sauce was actually 3.83 when I tested and although that's fine, it also demonstrates further fermentation is possible it so I've put it back in the fermentation bucket and am gonna leave it for another week. This is what it's like when fermenting, you can't rush things - you just have to be patient....