Milk chocolate bubble trouble

[Edward J]

Got myself a head scratcher.

Making solid milk 50 gr (2 oz) chocolate bars, but am plauged with bubbles on the back. It's a fairly fluid couverture, 34% cocoa butter, 38% cocoa solids. I fill the mold, vibrate for about 45 seconds, lay a sheet of plastic over the back and scrape smooth.

At first, it looks great, but after a few minutes bubbles appear under the plastic, and when it hardens, these appear as large blisters.

I do the same with a 70% dark with no troubles. I do the same with the same milk couverture and chopped nuts with no troubles.

Any suggestions?

[gap]

At the risk of being shot down in flames could all of the vibrating be causing the bubbles given the fluidity of the chocolate? Maybe just try a couple of test moulds and bang them on your bench. If the problem disappears, you could try vibrating for 10-15 seconds instead of 45. Just a thought, no basis for it.

[Edward J]

It's worth a shot, try it tommorow.

[Lior]

Isnt 45 secs a long time? I actually have never timed myself-never though of that! Now I wonder how long I do it for?

editted to add-really cute topic title!!

Edited July 8, 2011 by Lior (log)

[nanefy]

OK, I'm a pure amateur here and please feel free to ignore what I am about to say, but I know from having worked with silicone, that to get rid of all air bubbles (assuming you don't have a vacuum chamber) you pour the silicone from a decent height, in order to stretch out the bubbles and they pop - now in my mind (bearing in mind I am certainly no chocolate expert) could this not work with chocolate too???

[Chocolot]

Are you sure on your percentages? 34% cb, 38% cocoa solids. Never seen a milk chocolate with those numbers.

[Edward J]

Yup.

Cocoa butter solids 38%

Cocoa butter 34%

Lindt "Extra au Lait"

Nice stuff, but very fluid.

Mentally back tracking here. The other night I filled the melter, and set it around 45 C to melt overnight. Next morning, tempered with about 1/4 more couverture, then let it rest for maybe an hour. But when I think about it, the tank had a lot of bubbles in it. I wasn't stirring excessively either.