Kinda new to the homebrew thing but im on about my 8th batch 3rd batch all grain. So my problem is everything is going fine beer tastes ok when the beer is done fermenting and We keg or bottle it it is gold in color but it ends up turning to a darker brown later on within about 3 weeks or so we use paint strainers to try and catch anything that we happen to suck up durring transfer is oxidation causing this? Right now we are using buckets to ferment but i did just order a Spikes 15gal conical with the temp kit. Would cold crashing help this and if so how long do I cold crash for?