I brewed a chocolate milk stout almost 4 weeks ago and I had intended to bottle this evening. I realised that I don’t have any bottle caps and I have visitors arriving tomorrow and won’t get a chance to bottle for another 2-3 weeks. Is it ok for me to leave it in the primary bucket sitting on the yeast for that long or do I need to rack it to a secondary (something I’ve never done before)? If I do need to rack it, my carboy is a 6 gallon and there will probably be quite a bit of head space for a 5 gallon batch, will this cause any problems?
If it were me, I would leave it. I feel the risk of any off flavors from the yeast is less than the risk off flavors from oxygen in the headspace.
Don’t rack it, leave it as is. I’ve lost count of the batches I’ve left on yeast that long over the years. There is benefit to leaving beer on yeast beyond the end of fermentation - namely giving the yeast a chance to reduce unpleasant compounds (such as acetaldehyde and diacetyl) to below noticeable levels, and in short age out ‘green’ flavors and aromas. Leave it !
Me too. Leave it. There will be more benefits and no harm.
Thanks, that’s a relief. 
So why do we go to a secondary in the first place?
Many of us don’t secondary, except when adding fruit or dry hopping or extended aging.
There are a lot of things in homebrewing that continue to be done because “that’s how it’s always been done”. A lot of what we do was initially modeled after how pro brewers work, even if it’s not needed at homebrew scales. I’m guessing the whole secondary thing is because pro brewers typically use a secondary bright tank to help clear their beer. It’s not really needed at the homebrew level, and may actually cause more harm than good.
+1 to being lazy. Sometimes it pays off = decreased oxidation risks as well as decreased infection risks.
+1 to not using a secondary because it’s how things were always done. But I do use one after fermentation is complete for fruit beers and dry hopping with good results.
I wouldn’t fear leaving it in the primary that long. Nor would I fear racking it.
John Palmer and many others recommend not using a secondary…
https://www.homebrewersassociation.org/forum/index.php?topic=15108.msg191642#msg191642
Thank you very much good sir! The amount of knowledge I’ve picked up in the few weeks I’ve been on here is insane!
What’s the ABV%? How is it being stored? I’ve personally left brews on Primary for 4 -5 weeks with no issues but I usually keep them cool when I do.