Please explain discrepancy in ABV for my still

[BamaDave]

Last week I made a sacrificial run, which wasn't much of a sacrifice except for a few dollars, with 1/2 gallon 190 everclear and about 4 gallons water. I ran a little fast, started out a good stream but trimmed the heat back to around 5 drops/second. I caught separate glasses at 150ml which most of them came in between 65 -75 % ABV for most of the run. This is a pot still, you can see pictures and details of the run under my post in the "Firsts" forum. So anyways, tonight I decided to make my run with my all grain wash that I had fermented a few weeks ago. The only physical change I made to my still was, I broke the column down, which is about 3' tall and packed the entire thing with copper mesh. Not took tight, just the way I have read here. I thought that would bump up the ABV just a slight amount and add a little reflux to the run. I also brought the temp up a little slower this time in hopes I wouldn't get the initial pouring stream when it started. That worked fine and when I saw a trickle I started the condenser water and backed the temp way down to about 3 drips/second. I thought this would make for a cleaner run and make it easier for me to make the cuts.

To my question, my first 150ml came in at 64% and most all of them ranged between 50 - 60% no matter how much tweaking I did. What happened between the last run and this run to cause the ABV to drop so much? I assumed with the packing and running a little slower I would have been pushing 80% or at least stayed in the same range. I never thought I would have dropped the ABV.

Any help is greatly appreciated!

I will post all the details of my run under the firsts forum as well for my first all grain run but it will be tomorrow. I am flat busted tonight.

On the good side, I took a few swigs of jars 6-9, which I thought were right in my hearts and that was some amazing tasting corn whiskey! Much much better than I expected.