The problem with the day was a lower than expected brewhouse mash efficiency. We'd accounted for 67%, but only wound up at around 64%. Now, 67% is nothing great, so getting even lower than that was quite disappointing (though not surprising - we always seem to get low efficiency). After reviewing the day, there are certain things that pop up that may have contributed to this underperformance.
1. Denatured enzymes
- Cause
- We were >10° too high for 10-20 minutes or so. A percentage of alpha amylase might have denatured in that time leading to lower saccharification. As a result, a lot of the grist in the bottom of the fermenters might actually be unconverted starches. This was likely the result of the probe measuring a cold spot.
- Fix
- Mix strike water well and then read temp before striking to ensure uniform and precise dough-in temperatures
- Cause
- I think that, regardless of the water-to-grist ratio of 1.7 qts/lb, the degree to which the grain was packed in the bags made that moot. It's likely that the alpha amylase didn't have adequate free range of movement within the bags to fully access and convert starches to sugars.
- Fix
- Use butcher twine to tie off bags at the top rather than tying the bag with itself, thereby greatly reducing internal bag volume.
- Cause
- The bags of grain were really hot when we sparged. We attempted to squeeze wort out as best we could, but we probably could have squeezed more wort out if they weren't so hot and burning our hands.
- Fix
- Possibly a dowel with a hook on the side into which the bag's knot gets strapped, then roll the bag up and let gravity squeeze it out. Or get heat safe neoprene gloves to just squeeze by hand.
 |
| Rolling up grain to squeeze it out |
No comments:
Post a Comment