Numbers from yesterday: #1 is basically 24hrs behind the Control. I think one of the interesting comparisons is #2 vs #1, where #1 shows a distinctly better attenuation profile - why is this? The difference was likely down to the absence or presence of yeast catalase which has been shown to act as a catalyst in the 2H2O2 -> 2H2O + O2 reaction. The actual dosage into #1 was 320ppm H2O2, or 0.032% in the 150mL starter. I said 160ppm but this was really the maximum potential O2, and it didn't necessarily get there. I gave it 40min in an unmixed situation to break down everything into O2, but a few web references (e.g. this one here, where the lowest was 0.09% or about 3x stronger) point to low concentrations like this taking potentially a number of hours to fully break down. I'm not picking up any yeast health issues at this stage from getting whacked with 320ppm H2O2 either, even though yeast is apparently only equipped to deal with ppb levels....... we will see in future tasting though. I will get a few of the CQ guys to have a taste and will probably throw a few around the Brisbane swap to get some feedback. I'm leaning towards another experiment comparing stirplate and stirplate + H2O2 in a split lager batch. I would hope that stirring and 4-6hrs would be enough time to decompose the H2O2 to O2, with any excess just leaving as O2 gas. This for me would be the real test as I want something simple to help push lagers along rather than having a wand, stone, O2 regulator and bottle getting used for 5min once a month and being unused in the shed for the rest of the time. It would be good to see an experiment with gaseous O2 into the wort before pitching to compare wort freshness vs H2O2 on a stirplate, as well as the attenuation comparison. Although H2O2 does have a higher oxidation potential than gaseous O2, I wonder how much wort freshness is being lost with oxygenation prior to pitching?