Recent content by RPh_guy

Edit: nevermind.

Thank you. I hope we can now conclude the philosophy discussion.

I'm unable to understand that hobbists are happy with bare minimum effort to achieve subjectively adequate results? Wow, I must not be very bright. FYI Formol titration was invented in 1907. It's not new technology, and not particularly difficult or expensive when compared to the rest of the...

So, what's holding people back from testing? The titration is relatively simple, not much different than measuring TA. I suspect you could even use the phenolphthalein indicator instead of a pH meter. I think research is pretty clear that excessive or inadequate nutrient levels both have...

The sticky in this subforum says it's impossible to test YAN at home. :( I'm surprised no one here thinks knowing nitrogen levels is helpful. Are you guys also not testing pH, TA, or density? None of those tests are necessary either. If you already own & use any pH meter - then adding on YAN...

Do you use it for YAN testing?

.... The Vinmetrica test uses 37% Formaldehyde. From my understanding, the only function of the Vinmetrica device in this test (called a "formol titration") is to serve as a pH meter. Any pH meter will work fine for the test.

YAN = Yeast Assimilable Nitrogen, which includes both ammonia and amino acids (FAN) Along with pH, TA, and s.g./Brix, YAN is one of the most important aspects of a wine, and one that we can measure. Does anyone measure it? If yes, can you describe your process?

Your understanding is correct with regard to mercaptans and disulfides. However it's still unclear whether H2S contributes to forming these compounds. Copper sulfate is not any more toxic than Reduless if the product is used appropriately. However, if the powder form is more convenient, then...

This has only been theorized, never proven. Check out the article I linked in the previous post. Arguably copper sulfate gives greater control over VSC removal than Reduless because you can more easily do a bench trial. It's not toxic when used appropriately. Reduless allegedly has fringe...

= 0.68 mL/gal I measured 152ppm free SO2 with my AO kit, and added enough H2O2 to target 40ppm, with a 10% safety margin as the AWRI suggested (very slowly with gentle stirring). After that I let it sit for a couple hours. I couldn't detect any SO2 with my nose at that point so I went ahead...

Sulfite does not directly add a sulfurous taste. The sulfur taste is caused by H2S or other VSC like ethyl mercaptan. H2S may occur during fermentation or it may occur when adding sulfite too soon after fermentation. Sulfite - Modern Brewhouse wiki Hydrogen sulfide - Modern Brewhouse wiki...

This isn't correct. According to other sources, 0.67mL/ US gallon is appropriate (based on the chemistry), and the AWRI suggest a 10% safety margin, which comes to 0.60mL/US gal of 3% H2O2 to remove 10ppm SO2. I finally acquired some H2O2 and am ready to give this a go.

For those looking to learn more about H2S, I've covered this off flavor extensively on my wiki: Hydrogen sulfide - Modern Brewhouse wiki While bacteria can certainly produce H2S, I didn't come across any research specifically about MLF. Cheers

Thanks! I hope it's helpful. I have to wonder whether the tannins might appear to have an effect only because oxygen is behind introduced. Check out the section in the article about removal. The "nuclear option" of using aeration plus an unknown amount of copper may not always be the best...