Using Chux as a dry hop bag? First attempt dry hopping

[pat86]

Yeah I was going to ferment for 15 days as that is when I will next have time to bottle.

If I am to cold crash how many days before bottling should I do this and at what temp?

I currently have it at at 18 degrees.

Chill it after it has finished fermenting and not before - especially if you are bottling. Different yeasts take different amounts of time and while 15 days should be more than enough provided you have pitched enough yeast, oxygenated enough, etc you won't know for sure unless you get a stable gravity in the expected range.

Once it has reached terminal gravity, a few more days in contact with the yeast is beneficial to ensure yeast cleans up its byproducts. Then as cold as you can for as long as you like but to get noticeable benefit - try at least 48 hours. More is better

What Manticle said - you need to make sure fermentation is fully complete (otherwise you risk bottle bombs) - so get a stable gravity reading for 2 or 3 days in a row and then drop your temperature down to around 0C-3C. John Palmer also recommends a few days after F.G. sitting on the yeast to clean up. I haven't really experimented and couldn't tell you what kind of flavour difference this makes, but F.G. has usually taken 5-9 days for me, and I often CC on day 13-15. John Palmer > me.

I am sure smarter people know the freezing point of beer, but I had a FV get down to -1.5C by accident and it didn't freeze. I'm sure 2 degrees accomplishes the same thing, really, the colder the better. If your fridge only got to 10C I'm sure that would still be beneficial in terms of clearing and helping particles drop out. I am usually impatient so have CC'd for 1-2 days and right now have one that has been 15 days.