Also remember there will be some small amount of air in the fabric that comes out during the infusion process.  You always introduce a little bit through the resin feed  line initially.

Warren Penalver
Easy Composites / Carbon Mods - Technical Support Assistant

I used my resin trap to degas a small batch of resin in a cup. It formed a nice frothy head that subsequently clollapsed when I released the vacuum. The resin was still bubbling a bit after about five minutes of vacuum so I figure some of could be something other than air coming from the resin? A byproduct gas?

The mentioned effect has nothing to do with the oxygen bound in the water molecules. Although water molecueles break up from time to time this creates (small amounts of) oh- and h3o+ ions, and no oxygen.
I am talking about physical solution. Every fluid/solid solutes molecules of the surrounding atmosphere. This depends on the substances involved, and the partial pressures. If you reduce the pressure of the system, you reduce the partial pressure of the surrounding atmosphere. As a result the substances in solution leave the liquid.
In our infusion setup, we are talking mostly about water molecules (as far as I know), which solute quite well in epoxy resin.

Well water at a molecular level is a product of oxygen and hydrogen, so of course there will always be air in the ocean for fish to breathe - without the oxygen you wouldn't have water. It is possible to completely degass an epoxy - assuming of course that it is a 100% solids epoxy; solvents will outgass forever - it just generally takes quite a long time and in most cases takes up far too much of the workable pot-life. It is also mostly unnecessary, as once the resin has 'foamed' and then collapsed, there is only a small amount of air left in the resin. 

Thanks all. I have a small fiddly part to infuse this weekend. I'll use my runny slow cure resin and degas it in my resin trap after mixing to see what happens. Can't hurt but there are so many variables..

If you do a corret degassing (proper chamber, full vacuum) you'll notice that even a crystal clear resin still degasses quite a lot of air. Even if you just degas your resin without stirring and without adding hardener, there will be air inside your resin. This is a physical effect, and absolutely unavoidable. Think of  the ocean: fishes ares able to get oxygen of of the water. And there is no visible air trapped.
This small amount of air is might not be the problem in a infusion, as there is a pressure gradient through your part. Only the resin at the resin front is at vacuum strong enough to pull air out of the resin. But if you clamp of the resin line to early, you'll end up with your whole part under allmost full vacuum. And as the resin does not flow anymore, the small amounts of degassed air have no where to go, but to stay in the cloth. There the small bubbles collect and form greater ones, typically at the small gaps between crossing fibres.
I am 100% sure that more resin/later clamp of will solve your problem, but will end up in a slightly heavier part.
Alternatively you could degas your resin at a higher vacuum, than the final pressure in your cavity, to ensure that there will be no degassing.

If you're mould was porous, you'd definitely see evidence of air ingress during the infusion

As Hanaldo said, degassing is largely unnecessary to achieve perfect cosmetics. I too do infusions nearly every day and no longer bother using my degassing chamber as there has been no noticeable difference to parts even when starting the infusion very soon after mixing.

A lot of the trapped air will evacuate during the infusion process anyway and ensuring that enough resin has flowed to wet-out the stack is key to ensuring a perfect surface finish. Using resin breaks and making sure that every bit of your part has fully wet-out (even any excess peel ply near the exit) should ensure that your part comes out without voids, as appears to be the issue you've highlighted. Slowing things down is also helpful when using small-ish moulds

Thanks for all the feedback.

I guess degassing may depend on the resin and how you stir it up- if you trap a lot of air.   

I don't degas and have not had pinholes, but the resin I doesn't give me enough open time to degas.  I wonder if the extremely slow cure time played a part in creating the voids.  Anyway, it won't hurt to degas it next time.

What is your mold made of?  Is it possible that some pinholes in the mold surface allowed air to be drawn up from it?

I can definitely say that degassing could be a very important part of the infusion process. Maybe it might work for some people without degassing. Possible factors might be the resin, the mixing techniques, the shape of the final part, etc. At first, infusion worked quite well without degassing. There where some pinholes most times, but far less than in my wet laid parts. But as the parts became bigger and more complicated, the pinholes got more, so I tried degassing. Since then there never was a pinhole again.
You said, that the needle didn't move during cure. This implicates that you part was under full vacuum during cure. Without degassing I would recommend not to do that. The smallest bubbles become 1000 times bigger under full vacuum. If you don't want to degas, clamp of the vacuum line first, and let some additional resin soak in. Than clamp of the resin line. This should help a lot reducing pinholes.