Just use plain (unflavored) Knoxx gelatin from the Walmart or your local supermarket. You don't need much, about 1 teaspoon of the powder per 5 gallons, pre-dissolved in a cup of hot (not boiling) water, before adding.This gelatin. I don't have it but I have seen it a dozen times so I assume next time I'll dump some into my fermzilla before transferring from 23c to 6c.
Example instructions: How to Clear Your Beer with Gelatin - Wine Making and Beer Brewing Blog - Adventures in Homebrewing
next time I'll dump some into my fermzilla before transferring from 23c to 6c.
You don't always need gelatin to clear, just cold temps and time will do it, the colder the better, such as -1°C. But gelatin helps when in a hurry or after a week cold crashing it's still hazy. Now Wheat beers (Hefeweizen, (Belgian) WitBier, many American Wheat beers, etc.) are traditionally hazy, keep that in mind.
Cold crashing, beware!!!
In light of things shrinking due to cold, make sure when cold crashing your fermenter is either:
a) not closed, or
b) has positive CO2 pressure, or
c) an expansion/contraction device.
Otherwise it will start to implode...
You can achieve this by one of these solutions:
a) leaving your airlock connected (S-shape preferred), so some air can get in when needed, or
b) leave CO2 in there under (slight) pressure (by use of a spunding valve during fermentation, or pressurized with a CO2 tank), or
c) using a Mylar (party) balloon, filled with CO2, connected to your airlock or a tube, to supply CO2 to your fermenter during chilling.
Now it's also important to prevent your beer from oxygen (air) exposure after fermentation has started. This becomes more important when fermentation has slowed or has ended as there is not enough or no more CO2 being generated to drive off any oxygen that (inadvertently) got in.
So be aware of this while tinkering with beer, and during cold crashing. Solutions b) and c) can protect your beer from oxygen ingress during cold crashing.
Although these are more advanced techniques, they're not all that difficult to apply, and can make a big difference to your final beer.