first extract in a while

i rarely do extract batches, but since my friend wanted me to teach him how to brew, i though an extract would be easiest to teach. and of course the brew he wanted to do was Midas Touch. the recipe I got showed an OG of 1.086. but after we were done on brew day our OG was 1.070 ish.

Just need a reminder on how efficiency works with extract batches. there were no specialty grains or partial mash involved so i figured my OG should be the same as the original recipe showed. how can your efficiency change while doing extract batches? (i know lots of sugar would come from the honey and muscat concentrate for midas touch clones, just dunno how much.)

If I remember right, the grape juice is added in secondary. So that might complete the listed OG.