When it comes to bubbles from SB, I recently tried a new SB when I realized my regular one was downstairs. My “regular” one is a kitchenaid, and even though I burp it I was still getting air bubbles. The one I used that gave me no air bubbles whatsoever was a cheap Proctor Silex blender (one piece, no removable shaft). My theory is that because the blade on this SB is much smaller than my kitchen aid less air is being introduced. Perhaps not as good for cooking but great for soap making. I always snubbed my nose at the cheap blenders but now see the light.