Are starters that foam a lot normal?

[RegionalChaos]

I recently harvested some yeast from a bottle. This is my third starter. I made a small starter at first, then a few days later fed it a few pints of wort. It seems to have worked well. I have some good looking yeast on the bottom, the beer looks ok and the smell coming out of the starter is good (yet still on the sweet side). However, when I swirl the starter a few times (its in a half gallon jug) the sucker foams like crazy. It looks like there is a lot of co2 in there. I see a ton of bubbles. The head is easily 3 inches plus tall. Is this typical? The other starters I made didn't foam to this extreme. This starter has been hanging out in my bedroom at room temp (70-72 f.). I'm planning to let it finish out well (probably just another day really) and then throw it in a few pint jars and baby food jars for future use.

Does the foaming seem typical?

 

[Arneba28]

its probably just degassing a bit and a small amount of fermentation is still going on. I have had 1/2gal starters that needed a blowoff tube and foamed if I looked at them wrong...dont worry