How quick does the coffee flavor last

I recently brewed 10 gallons of a coffee stout. The batch was split between two carboys. After 15 days I added the same amount of cold pressed coffee concentrate to each carboy. I kegged one 5 days later(day 20) and the coffee came through perfectly and tasted awesome. I bottled the other carboy on day 30. I tasted one a week later on day 37 and while it was under carbonated it had no coffee flavor at all. The kegged version still has coffee flavor.

I did not do a secondary for either batch. I assume the coffee flavor got pulled down to the trub. That is the only thing I can think of.

Any other ideas as to why the coffee flavor did not come through in the second carboy?

Edit: I used 12 ounces of ground local coffee to cold press. I let it sit in the fridge for 12 hours with just under a gallon of water.

the coffee flavor cant really get pulled down and settle out like yeast. Ive found that it can fade with time though not as quickly as hops. Ive had better success using whole beans in teh primary to get a very smooth and rounded coffee flavor. This also seems to last longer IME

I used espresso beans just dumped in to primary on my recent stout. Its been in bottles for 5-6 months and still tastes like a nice cup of iced coffee. I guess it's mellowed a little, but definitely not completed dropped out. I've never done it a different way.

m00ps said:

the coffee flavor cant really get pulled down and settle out like yeast. Ive found that it can fade with time though not as quickly as hops. Ive had better success using whole beans in teh primary to get a very smooth and rounded coffee flavor. This also seems to last longer IME

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I do the same and completely agree. I like to give my beans a course crush, then add them to a sanitized bag, and "dry hop" in the keg per say. The coffee aroma/flavor tend to stay with the keg until it kicks. Ill do 24-48hrs for coffee presence, or a few more days for a more pronounced coffee flavor.