Jim, First off, why press the honey out? Doesn't that destroy the combs? I found a small two frame extractor for $80 at a bee supply house near here. For a hobbyist, it's just the right size. The air bubbles you are seeing (or "foam" in its worse case,) come from dropping honey into a container. It needs to slide down a surface. You also get this when you pour it into jars, etc., if you don't pour down the side. It will persist for some time. Let it settle to the top and skim it off for your own table use.