Well, color me very surprised. I am about 40-something hours into the experiment and at least 2 of the batches have reached my expected terminal gravity (plus or minus a gravity point). Here is how things stack up so far:
- Batch A | Half Pitch Rate: 1.065, showed some slight signs of fermentation within 4 hours, but minimal bubble and churn visible.
- Batch B | Control Pitch Rate: 1.065, showed solid and strong fermentation within 2 hours, at 4 hours significant production bowed the top of the container with pressure. No krausen in the blow off tube however
- Batch C | Double Pitch Rate: 1.065, showed strong fermentation within 1 hour of pitching. Significant blow off with krausen in the tube by 2 hours
- Notes: careful re-hydration seems to have caused very short lag times combined with pitching at warmer temperatures. Ambient temperature between vessels was about 78F. Room temp at 72F.
- Batch A: 13 brix / 1.044, steady fermentation, but nothing exciting. Very little krausen on glass. Replaced blow off with airlock.
- Batch B: 10.75 brix / 1.028, steady fermentation, pressure released and no bowing in the lid. Replaced blow off with airlock.
- Batch C: 9 brix / 1.018, well ahead of the others, however strong fermentation has slowed to a steady pace. Still churning in jug. Replace blow off with airlock.
- Notes: ambient temperature taken between vessels at 71F.
- Batch A: 8 brix / 1.011, still steady but slow fermentation, but is catching up to the others.
- Batch B: 7.5 brix / 1.008, slow steady release of gas. Near final gravity already
- Batch C: 7.5 brix / 1.008, same as B at this point.
- Notes: Surprised that we reached more or less terminal gravity at less than 2 days.
I should note that I am using a refractometer for the brix readings and converting the reading to SG in BeerSmith – so take those with a grain of salt. The OG was taken with a calibrated hydrometer. However, I intend to let this ride at least a week and will continue to use refractometer readings to confirm we have reached final gravity in each batch. I am also guessing that at this small scale, time frames may be affected – this is certainly not real world testing in 5 gallon or 7.5 barrel batches side by side. If I had thought ahead properly – would have also taken pH readings…