I bought 3 extract kits from NB in around October and brewed last one in January. The first 2 were brewed in late December and I did taste some extract twang in them. The last one came out 85% as good as the fresh batches that I've made of the same recipe. Maybe it is because I cold crashed it for longer but its definitely better.
I ran into some problems that prevented me from brewing for some time and that caused a long delay. From now on I plan to brew a kit within 1 month of getting it. I ruined one kit by breaking a thermometer in my pot and it was 2 months old and when I opened LME to use for a starter it had mold in it.
Old school or the new, doesnt mean a thing if your heart's not true!
Primary: 04/29 Pomegranate Nectarine Apfelwein, 05/23 Petite Saison
Kegs drinking: AHS Midnight Wheaten Stout 03/18 - 04/14 - 04/28,
Kegs conditioning: 01/29 - 04/29 Cranberry Apfelwein, 04/29-05/23 Petite Saison
RIP: 11/07-11/28-01/29-05/04-11/17 Flanders Brown Ale