Dark layer at top question

I brewed my first batch, a Rogue Dead Guy Ale, on August 28th, racked it to secondary on September 29th, and today for the first time I noticed the top inch our so is somewhat significantly darker. It is the top layer oxidizing from possible oxygen in there or is it maybe more yeast settling? If it’s yeast settling, do I WANT this to happen before I bottle or do I want to bottle while more yeast is in suspension? I’ve attached pictures, but the difference in color isn’t quite as great in person, because the flash is really lightening the rest of the beer. Thanks in advance!

That looks to me like it is yeast settling and your beer is becoming very clear. You do want this to happen. When you rack this to your bottling bucket your siphon will be at the bottom and you will get some yeast moved over. Keep an eye on the line and you will probably see some chunks of yeast move over. If not you can move the siphon a little and it will stir up some yeast and suck it over. You really don’t need much for bottling and you don’t want too much or you will get a thick layer in the bottom of the bottle.

So you don’t siphon the same as you do from primary? You actually want the siphon at the bottom when you move it over to the bottling bucket instead of siphoning from the middle? Thanks for the help!

Yeah it’s just yeast settling and as they do so, the clear beer doesn’t reflect the light as much as yeasty beer so it appears darker.
When you syphon try to get as little yeast as possible, but if you do suck them up it’s no big deal. There will still be enough in there to carbonate.

What kind of siphon are you using? I use an auto siphon http://www.northernbrewer.com/shop/auto … -5-16.html
it has a cap on the end that goes into the beer and keeps you from getting down into the yeast and sucking all the trub over. Then when you are bottling you take the cap off and you can get almost every last drop out of the bottling bucket.

I have the autosiphon but I guess I figured it didn’t keep ALL of the trub out if you just put it at the bottom. Follow-on, if the dark layer is yeast settling out, than should the layer be getting thicker as more yeast settles? I marked the bottom of the dark layer but it hasn’t moved in 2 days…could it be something else? The current inch if darker beer developed within one day of racking to secondary but hasn’t budged in the days since…thanks again in advanc

The auto siphon with the cap on the end will do a fairly good job keeping most of the trub out. The reason for going into a secondary is to settle out the rest. All you are really doing is clearing the beer some, you really don’t improve the beer itself [there are lots of people on both sides of the ‘to secondary or not to secondary debate’ and NEITHER is wrong]. Personally I typically do a minimum of 3 weeks in the primary and then bottle or keg.
I cannot comment on the question of how fast the yeast will settle out, I stopped paying attention a couple of years ago. The beer will be good either way.