The second experiment posted on Bubble-Logger.com blog we wish to compare the use of vitality starter vs. directly pitch of 5g dry yeast. For both batches we make use of 5g dry yeast and for our Vitality starter this was started 24h prior to direct pitching. To give the vitality starter best conditions we make use of a stir plate.
The Bubble-Logger did for both batches seems to either under and over estimate BPM, and hence, the SG was way off. This sometimes happens and in this case the under-estimate (low yeast amount = direct pitch) was linked till the SS Brewtech Mini fermenter is hard to get airtight (last time I use these and the get back to my pal). The over-estimate (High yeast amount = Vitality starter) was showing a behavior it detected double amount of blops during the high kreuschen. Every time a blop was made and released a small tiny one followed and was likewise detected. This seems to be an issues very much connected till inferred detection and has not been seen in the sound version. This behavior of double bubbles is connected til the pressure was very low and hence a tiny appendix bubble follow the main bubble and where this tiny bubble get detected by inferred we can control/remove this in sound version by the sensitivity of the sound sensor though the pontiometer setting.
At the time I stopped logging both batches was hovering at 1020, and even I guess they will fall a bit more in SG, the data is fine to use for this experiment. There clearly show the activity of the yeast amount (e.g. the vitality starter hold more yeast as better treated) do involve on the activity, intensity and time to take off. The direct pitch yeast did start 12 hours later, and was more slow in intensity, and “completed” (reached 1020) nearly 1 day later.
If we instead of the BPM start look at the “Sum BPM/L” we can more clearly see the vitality starter yeast is holding an exponential behavior/growth, whereoff the direct pitch shows a much more lag-full behavior.
Looking at the temperature we can also here see it seems the activity have been severely higher at the Vitality starter yeast.
So even the SG estimate failed here, both the BPM and the “Sum BPM/L” can help indicating when to start to take SG measurements and or increase temperature. In these case both brews are reaching FG after 3 days, and as activity go down and the “Sum of BPM/L” is no longer increasing it is time to take first hydrometer measurement.