Exploding bonbons-what did I do wrong?

[patti_h]

I made bananas foster Bon bons for the favors for my parents 50th anniversary party favors, using the banana ganache recipe from M. Laiskonis' workbook. I made a dry caramel & added small thin shards of caramel into the ganache. They were completed Monday evening. On Wednesday I noticed a few had exploded so I replaced them in the boxes with another bonbon. Tonight I went to set them out & saw that every last one had exploded as in the attached photo. I made only one tray so I don't have a comparison. Any thoughts as to what I did wrong? I would prefer to avoid exploding anymore bonbons!

[HQAntithesis]

I've never heard of anything of the sort before -- how intriguing! Especially considering how, if anything, the ganache would retract. I had this thought the expansion might have been due to expansion of starch molecules or something but that's just silly. Banana ganaches simply would not work then.

My current feeling is, if the bananas were fresh, that there may have been some degree of fermentation that happened. Especially if you followed the instructions on the recipe because the bananas aren't heat treated at all (being added at 35C only). I may have miscalculated but I think that banana ganache recipe has a moisture content of 25% which is at the upper limit of acceptable water content for bonbons but if you combine that with using a fresh banana puree, that could essentially 'inoculate' the ganache Of course, that whole theory is debunked if the puree had been heat treated.

[Drewman]

My best guess is your outer shell was too thin and as the chocolate shell crystallized and shrank around the filling, the center burst out at the weakest point.

[Kerry Beal]

Yup - fermentation as mentioned by HQAntithesis. Yeasts react with the sugars to form alcohol and CO2.

[patti_h]

Well I'll be....never imagined that would happen. I just got finished cannibalizing two 12-piece boxes to refill all the orders I brought with me out of state this week. Next week I will be using Steve Lebowitz's bananas foster recipe he has posted here on eGullet! I have to say that this is one of the weirdest things I've had happen in the kitchen! But hey- it was a learning experience. Disappointing because that ganache had a great flavor, but Steve's sounds really yummy too.

I knew the eGulleters would be able to figure it out.

[Kerry Beal]

Might want to adapt the recipe to cook the bananas.

[Chocolot]

Did you smell and taste them to see if it was fermentation?

[curls]

When Joe made his banana's foster bonbon at the Woodbridge Chocolate Workshop, he cooked the bananas in butter and brown sugar. I held onto a couple of those bonbons for a few days and they did not shrink or explode. So I agree with Kerry, try adapting your current recipe to cook the bananas.

[patti_h]

Ruth- I did, and I think I could detect fermentation. Next time I'm using Steve's recipe- It was a learning experience though! People at my parents party ate the exploded ones and said they tasted great....but that was certainly disheartening to me!

[Tri2Cook]

I've never had a problem with the Laiskonis recipe but I've only done it with Boiron and Sicoly banana purees, never done it with fresh banana, so I'd be inclined to agree cooking your bananas would be a good place to start. I'm pretty certain I remember Michael Laiskonis saying on one of his blogs that he always uses commercial purees (when available in the flavor he's working with) for consistency in his products so I'm pretty sure that's what he would have used in the ganache recipe.

[patti_h]

That makes sense, although many of his recipes call for a fruit purée, 10% sugar, but this recipe called specifically for fresh bananas. I am quite certain the problem was on my end, Michael Laiskonis is pure genius! Also, if he was making this in the restaurant, I imagine they would be eaten before they ever had a chance to start to ferment.... I truly need to do some more studying. As soon as I quit one of my jobs!

[Tri2Cook]

It's possible we have different versions of his recipe. Mine just says "banana puree", it doesn't specify fresh or not.