Another big hiccup for Low Oxygen Brewing is people think they must have a dissolved oxygen meter, and while we feel they are invaluable in the brewhouse, it can be quite the expensive for a brewer wanting to try these methods out for the first time. I am here to talk you down from the ledge: its going to be ok! There is another solution that we find works well.
Sulfite test strips are available through Amazon (of course) and we have put them though their paces and are happy. Here is the link to them:
The only caveat is that you will need to raise pH to between 6-9 pH, which is simple enough with usually just a pinch of baking soda. They are an easy way to read DO, without actually having a meter. A sample of your strike water will show you that your starting amount of sulfites from your NaMeta dosage. You can then take readings thoughout the brewing process: dough in, end of mash, sparge, lauter, boil, etc. You can see where your various points of O2 ingress are, your “holes” so to speak, and use these to help you fix them. We recommend you aim for 10 ppm or less of sulfites remaining post boil (zero would be perfect), other wise you may run into some excess sulfur issues. Using these will make it easy to dial in your sulfite dosing. Its also interesting to use on the cold side to see the sulfite content (via sulfur) of the beer from the yeast. The aim here is 10 ppm or so from yeast. This will help you cold side for antioxidants.
Here are some samples from various parts of the process. They are very easy to read and use. I would not consider them “cheap” however, but at the price point of ~$30 its considerably cheaper than the DO meter at ~$250!
Starting dose of strike water:
Before Oxygenation (post boil, post chilling, post trub separation):