Have a batch of "customised kit" (+hops, OG upped to 1052 with DME) which was in primary using fermentis safeal S-04 ~20c. However went in yesterday (day 3) and found the fermenting bucket lid a couple of feet away from the bucket, and the beer exposed to the elements (my garage!). Very interesting spiral foam formations breaking through a crust - so must have been off a while!

Washed lid and replaced, and this morning no obvious nasties/colonies growing, primary subsiding, and beer tastest like, well nearly fermented beer. (no vinegar or other unfamiliar flavours - just bleedin hoppy!

Should I carry on and bottle as long as all seems well at the end of primary, or just dump it? My only keg is full - so no quarantine secondary or easy option possible.
Also - can you fit a airlock to a fermenting bucket - I am guesing this is the sensible thing to do, and would allow for a blowoff tube etc - is there a standard way of doing this? (My DIY skills tend to go a bit awry without careful instruction).
I am hoping any nasty spores werent hop-heads and perished a bitter death!

Many thanks