The stability of microfoam in my lattes seems to be greatly affected by the presence of crema in my espresso. I am wondering if anyone else has similar experience.

What happens is that all the brown areas on the top of my lattes grow large bubbles, but the white areas remain completely stable.

However if I remove the crema from before pouring the milk, the microfoam holds together in the brown areas as well as the white areas. The result is perfect, except that the contrast is not as good for pouring latte art.

I notice that the cafe where I buy my beans has a similar problem with bubble formation. The owner is quite clear that his beans are optimized for ristrettos, so perhaps it is something about his beans.

Regards,
Mike

P.S. I should also mention that I also get bubbles when I make hot chocolate. If anyone has good experience making hot chocolate, i.e., with stable foam, I would be interested to know what brand of chocolate you are using.

Try swirling the cup to smooth out the crema before pouring the milk. If that doesn't work, try pouring a little milk in the cup and then swirling. I saw a video of David Schomer doing that. He said he did it to get a nicer look.

Mike-R wrote:The stability of microfoam in my lattes seems to be greatly affected by the presence of crema in my espresso. I am wondering if anyone else has similar experience.

What happens is that all the brown areas on the top of my lattes grow large bubbles, but the white areas remain completely stable.

However if I remove the crema from before pouring the milk, the microfoam holds together in the brown areas as well as the white areas. The result is perfect, except that the contrast is not as good for pouring latte art.

I notice that the cafe where I buy my beans has a similar problem with bubble formation. The owner is quite clear that his beans are optimized for ristrettos, so perhaps it is something about his beans.

Regards,
Mike

P.S. I should also mention that I also get bubbles when I make hot chocolate. If anyone has good experience making hot chocolate, i.e., with stable foam, I would be interested to know what brand of chocolate you are using.

Maybe your brewing temperature is too hot? As for the cafe owner and his optimized ristretto beans, I suspect his bubble formation is more to do with his jabberwocky ability than his barista skills.

Is it light to medium-light roast?

Do you know the bean varietals in this espresso blend?

Ha, I've been thinking about this lately as well. It's not do to a certain bean or temp, its just how the creama reacts with the milk foam. It is really annoying though, but I guess its even more of a reason not to let your drink sit for to long.

This is relatively normal. In competitions the barista will often swirl the cup like you would steamed milk. You can also add a small amount of milk, then swirl/tap the cup to settle out the crema bubbles before you pour the entire drink. The other option is just drink faster.

Thanks everyone for the responses so far.

The beans are medium-dark roast with no visible oils. I'm not sure of the variety.

In regards to temp, I have the Mini Vivaldi II set to 95 degrees which works well for these beans.

I do normally swirl the crema, but I haven't tried to mix a bit of milk first. I'll give it a try.

I might try some different beans this weekend for comparison. I'll also try to take some videos and post.

Thanks again.

Mike

As promised, here is a video. Fast forward to the end to see the final bubbly conclusion.

http://vimeo.com/35008744

I have experienced this as well. I wonder if it could just be due to the fact that the when the foam mixes with the espresso (mostly water and crema is a lot less stable than milk foam), it produces a mixture with less stable foam characteristics where the surface tension of the bubbles isn't as strong so tiny bubbles merge to make bigger bubbles. Maybe similar to when you try to mix a liquid into whipped egg whites? not exactly the same effect but depicts how watery liquids don't mix with whipped/foamed proteins. I may or may not have had some bad pizza last night

Here is a comparison video of a latte made with the same beans but with the crema removed before pouring.

http://vimeo.com/35042526