I have been experiencing separation of ganache and have sought in vain for answers. When I make ganache by pouring hot cream over chocolate, then stirring, all goes well. But when I temper the chocolate to 84-86 F. (for white) and add cream plus flavorings at 105 F., the emulsion seems to be forming, then breaks with a mass and a separate pool of yellowish liquid. An immersion blender doesn't help, nor does the food processor. The only technique that has worked is to heat several tablespoons of cream and slowly mix the broken ganache into it with a whisk. This has worked every time (so far), although the result does not have the silky texture it should have.
I use several books for making ganaches, but the technique is basically from Peter Greweling (Chocolates & Confections). He states that a slabbed ganache should always be mixed with tempered chocolate. It is his recommended temperatures that I am using. The issue has occurred when I use Valrhona's Opalys white, although sometimes that chocolate (tempered) performs perfectly and mixes without a hitch. The Valrhona bag gives 84 F. as the desired working temperature.
What could it be? Temperature is a consideration, but I am using a Thermoworks infrared thermometer and also a Thermapen to check it. I am tempering with Mycryo, which I use for small batches. The recipe I was using most recently was Greweling's "toucans" (passion fruit ganache), with the change of tempering the chocolate before mixing it with the cream and passion fruit pure (because I was going to slab the ganache).
Any help would be most appreciated.
updated by @jim-dutton: 04/11/15 22:10:49