Slow long Hefeweizen fermentation?

I brewed up a Hefe last weekend, its been in the primary for 4 days. I have noted weak activity overall. I expected it to damn near need a blow-off tube as I freaked out Monday thinking my ceiling was going to be painted.

Anyhow I only have about 1 inch of krausen after 4-days. The yeast are swirling around well enough and trub is forming at the bottom. Obviously its alive and kicking, but it seems a lot less lackluster than I thought. My ambient room temps are right on 65'F. So I got a longer ride then most, my main question is, since this is fermenting out at such a low temp for this style what kind of flavor differences should I expect? I'm guessing it will lack much of its "banana" overtones.

It really depends on the yeast. Most German-style HWs like fermenting about 70-72F and produce a great banana flavor.

The lower temps usually produce a clovier brew.

If you prefer the banana flavor try moving it to a warmer spot.

what yeast are you using? you'll still get plenty of banana in the 60s if you are using WLP300. i ferment mine in the low 60s.

don't worry about your fermentation. let that puppy sit for few weeks and do its thing.

WLP051 California Ale V Yeast

From Northern California. This strain is more fruity than WLP001, and slightly more flocculent. Attenuation is lower, resulting in a fuller bodied beer than with WLP001.
Attenuation: 70-75%
Flocculation: Medium to High
Optimum Fermentation Temperature: 66-70°F
Alcohol Tolerance: Medium-High

I have never used that yeast, I am assuming this is an American Wheat then?

What ratio of wheat did you use and what is your other malt? I am trying to decide on 50/50 wheat/2row or if I should use a different ratio

you probably won't get any banana at all with that yeast. you need a good german hefeweizen yeast for that.

it'll be a nice, clean american hefeweizen. i'd be interested to see what malts/hops you used, too.