Extremely Quick fermentation

Ok so I brewed a pumpkin ale last weak with my buddy for his first brew. I used 9.9 lbs (LME)with only 1 lb of specialty and 3 lbs of puree pumpkin ( raw unsweetened), I always use a yeast nutrient and and i used WL American Ale yeast. Fermentation started real well (less than 15 hrs) but by the 4th day (eveningtime) there was still minor airlock activity and the Kraus was already 98 % gone. I have not tested the gravity yet because It is difficulty and i i dont want to risk contamination… i did pitch another yeast, a WL California Ale yeast but I did not introduce any oxygen because i know that some fermentation had occured and i did not want to risk oxidation… based on the brief info, does anyone think it was just a rapid fermentation or do you think i lost fermentation at some point. I did not have a highly roused Krauss at anytime during the brief fermenting period, maybe 1 inch the 2nd and 3rd day. … Please let me know what you guys think

Did you check the gravity before pitching the second yeast?

Sounds to me like the attenuative phase is done.

A warm fermentation will go quickly as well.

Have you taken a gravity reading? It might be done and thats the only way to know for sure. Sounds like you did not make a starter and you had a short lag and fast fermentation so my guess is you are fermenting way too warm. Any idea what the fermentation temp was? Keep in min  that fermentation can get was warm as 8+ degrees over ambient - and you generally want to keep fermentation temp under 68 degrees. So if you are fermenting in, say, a 70 degree room your temp is far too warm.

Yeah now that you mentioned it, it was warmer then usual in my fermenting room, probably above or around 70 degs. , also did not test the gravity yet, my plan is to rack it on Wednesday with my buddy and i will test it then… I appreciate everyones help, hopefully it turns out well. Thanks again

Do a search on swamp cooler - basically just a bucket filled part way with water that you rotate out frozen water bottles. Hard to make the best beer possible with temps that warm, but a little aging should round out the fusels and mellow out some of the excess esters. If you can’t manage cool fermentation temps during this time of he year you may be better off brewing saisons and other belgian style ales, which don’t produce as much fusels during warmer fermentation temps.