I use the cheapest I can find. Cheap vodka is just bitter (unfiltered) vodka. In a hoppy brew who cares? I once took cheap vodka and ran it through my Brita water pitcher. I used a new filter and ran the vodka through it three times. The vodka was smoother. I then ran water through the vodka-filter pitcher just to see what it would taste like. The water was Bitter, Bitter, Bitter. The difference between cheap and expensive vodka is filtering. It’s not worth it to filter vodka this way on a large scale!
I use a French press to make hop-vodka. I have a small press. I use 1/3 of an ounce of Amarillo hops (my favorite) and mix in vodka to dissolve the aroma oils. After ten minuets or so I press out the vodka and repeat this with water rather than vodka. Again I press out the water hops mixture and add it to the vodka hops mixture. I then dump out the hops into a plastic bag to freeze and reuse for bittering hops in some "odd beer" on other day.
I repeat this whole scenario three times to use the whole ounce of hops. I put the water-vodka mixture in a booze bottle. I use a Jack Daniels bottle? I set this in a refrigerator for a few days to let things settle. Even though it looks like a clear yellow liquid, it's not! After things settle down I carefully put the bottle (upright) in the freezer. In my case the water-vodka mixture turns to slush-ice in a couple of days. The hop residue is on the bottom of the bottle in a greenish band.
I then invert the square bottle into a coffee cravat that just holds the bottle securely and high enough off the bottom to allow the thawing vodka to drip into the cravat. The water which is frozen acts as a filter to the hop gunk now at the top of the inverted bottle. The first drippings are the purest but I try to gather all the vodka (and some water) into my “supreme hop vodka”. The later dripping’s are still good and I use them too. In fact I let it melt until it looks like the ice filter may collapse and dump in the hop gunk into my “hop water” The hop-water is great. I may dump it all in a keg of simple ale to kick it up a notch.
The supreme hop vodka stays in my refrigerator until I need a drop or two in a beer. You don’t need much. Half a shot glass would be more than enough. It doesn’t have a hoppy smell out of the cold bottle but in a brew, instant hop hit! You could even make a Bud taste good! Not that anyone here would have that stuff at home.
Sorry for the length of this. If anyone has questions contact me.