I know, when using extract, that efficiency is pretty well spelled out. You use this much LME or DME and you will get this OG and this FG. Yet, I have seen my efficiency go through the roof on my last two batches. Last night I bottled a ginger saison that I assumed would go down to 1.014, but it actually got down to 1.006, which threw my ABV up more than I wanted. The batch before that was expected to be a bout 9.6 ABV, a DIPA, but turned out to be 10.63. Now, the culprit may be the change in yeast. Previously I was using Wyeat, but on these two batches I used US-05 for the DIPA and Dan-star Saison. Are these two yeast creating this efficiency boost or could there be another culprit? I am not complaining, but I did not hope for a saison in the 7.5 ABV range. Any help would be greatly appreciated.