Safale 05/Tartness

I just brewed up 10 gallons of a All-Grain Cream Ale. 5 gallons with Safale 05 and 5 Gallons with White Labs 01. I just sampled both to get my Gravity readings so I can keg. Both tasted like young beer. 11 days old. Both tasted good with no noticeable off flavors. Although the Safale 05 batch has a tartness not sour like vinegar more like a light citrus. Is this the start of something bad? Should I worry?

I fermented both in the 60-68 degree range.

Nope. My first beer was an IPA with 05 and when I was taking gravity readings it was tart and "green". It stayed like that until about 2-3 weeks after bottling, when it then decided to become glorious.

Give it time, good things will happen.