A few months? You’ll get plenty of chlorophyll and other undesirables pulled that way. If you just want the flavor and essential oil you can freeze your plant material and the everclear, combine while still as cold as possible, shake for a few minutes… Maybe try a little bit and see if that might save you some time and give a better tasting extraction.

95% ethanol is pleanty strong enough for a quick extraction imho

Will Everclear freeze (in a typical home freezer)? Or does this require going out for dry ice?

Pure ethanol freezes at -173 C. Everclear is closer to -50 C. You’ll definitely need dry ice to freeze it unless you have an industrial deep freezer.

Edit: i reread your comment and the op. Op isn’t saying freeze the ethanol solid. They’re saying put the ethanol in the freezer with the basil so that they both cool down. The ethanol will remain liquid but be colder. You get a better extraction with fewer contaminants that way.

I have been my own alcohol based tinctures using different herbs both culinary and medicinal. I made 4 oz of a basil tincture last summer with some of extra basil using a similar method. (I used 151 proof EverClear since we can’t buy the 190 proof here and I did mine in an exact 1:2 (w/v) ratio instead of the more traditional folk method like you used here.)

It shouldn’t only take 4-5 weeks to get full extraction and it is delicious. I have been using it in cocktails and taking a dropper full when I want the benefits of basil. (Most for digestion when feeling gassy or ate too much. But I do take it when I am feeling a bit of a cold coming on as well). It is super fun and nice to have a few tinctures around. I have almost a dozen now and its nice to have. If I have one recommendation is try to get an old cheap metal Potato Ricer which allows you to squeeze all of liquid out of your basil leaves when they are done. It is worth it.

I would love to know where you found this method? I have read a lot of herbalism books and went to school for Chemistry and nothing I have seen would suggest this. In fact my organic chemistry knowledge is screaming that making things colder make everything run slower. By freezing something you may be rupturing the cell walls but the ice crystals are shredding and denaturing all of the compounds you are extracting. As a general rule things move fast at higher temperatures since the average speed of the molecules increase which has more energy to react. If you wanted to get this done faster you would need to heat the solution not freeze it. Especially since OP is using the standard Folk Tincturing Method method which works great if not fast. I have seen modifications that start with the solution below boiling and then let sit for time but that is generally done with things like honey which is easier to pour that way. I haven’t seen it with alcohol since that will reduce the alcohol content since the alcohol will boil before the water.

I know when making a cocktail you want to put the herbs in the cocktail shaker first and then muddle in some liquor. This will allow the cell walls to rupture and the alcohol will pull out all of the flavor. After you add ice and shake with the rest of the ingredients. The solid ice will continue to break the material and the additional water will extract additional materials while chilling down the drink which provides a better flavor. But you don’t freeze it.