Jim D.

I haven't made the original Greweling recipe for a while (I developed a different version of it), but I do recall that it did not firm up enough, and I ended up having to add more chocolate/cocoa butter. So you did not have this issue?

The last time I tested a plain caramel (Notter's recipe, intended to be piped into molds), the water activity reading was 0.56. As I think is the case with pâte de fruit, the sugar more than counteracts any water present. With an Aw of 0.56, the product can last for practically forever. And I think one can rely on getting a reading in this neighborhood since a caramel doesn't form until a certain percentage of liquid has evaporated. So if you add more liquid, you have to cook the mixture until it reaches that magic point once again. That's why I have sometimes found it convenient to make larger batches of caramel and then reheat any leftovers to use on another occasion (how's that for tempting the caramel gods--who can be as fickle as the chocolate deities!).

I use cream for thinning out, but I don't see why passion fruit purée would not work. Someone on eG previously mentioned using water. Since it is the water that has evaporated during cooking, water does make sense.

Yes, they look a little offputting, but it really works! Thanks, Kerry, for this idea.

Chris, Yes, spraying was what Kerry originally suggested. As I said then, setting up my airbrush is too much trouble, compared to grabbing a paintbrush.

I thought I should update my experiments with controlling leaking from caramel fillings in chocolates. I tried Kerry's idea of covering the top (eventually to be the bottom) of the caramel by painting on a thin but complete layer of melted cocoa butter. I then closed the bonbon with a layer of chocolate spread twice (with a slight pause between applying the layers). I had tried the double-closing before, with some success. This time, with the addition of the layer of cocoa butter, I saw no leaking in any of the finished pieces. So, thanks to Kerry for leading me to what will now be my standard practice with caramel fillings or any filling that looks as if it might leak. A nuisance yes, but worth it, I would say.

To complete the record of my pistachio experimentation: Contrary to expectations, after a full day, the purchased pistachio paste mixed with an equal part of white chocolate firmed up enough so that it could be piped. It definitely tasted of pistachio. Also contrary to my previous impression, adding some toasted pistachios makes for a stronger pistachio taste, and because no liquid has been added to the mixture, the nuts do not get soggy. On the other hand, the homemade pistachio praline paste, while delicious on ice cream, tastes primarily of caramel. I look forward to trying Valrhona's product to see what they may have done with it.

I thought I should report on today's experimentation, the goal being to create a pistachio praline gianduja: I caramelized some sugar and glucose and added it to pistachio paste (both fairly close to the same temperature). It is, of course, not possible to let the caramel cool or it completely hardens. When the two are mixed, the caramel hardens into lumps. I melted this mixture over hot water, and most of the caramel eventually melted, but the overall texture was not acceptable as it contained clumps of caramel which only increased as the mixture cooled. Perhaps most significantly, the taste of the caramel mostly overpowered that of the pistachio, so the big clue was that pistachio is much more delicate in flavor than I thought (as @jmacnaughtan pointed out earlier). Second try was to make pistachio praline paste from scratch: I caramelized sugar and glucose, added toasted pistachios, poured the mixture onto a Silpat, then ground it to paste in a food processor. It was not (no surprise here) completely smooth. I added an equal amount of white chocolate and melted the two together to make a gianduja. The final taste was quite bland, with the taste of the Valrhona Opalys chocolate predominant. Third approach was simply to mix equal parts of the pistachio paste (no caramel added) and white chocolate, again to make gianduja. The taste is by far the best of the attempts, with a strong pistachio taste. I added some toasted, chopped pistachios with the thought that they might add even more flavor, but whereas they do add a nice texture, I did not perceive any additional flavor. The problem with the gianduja is the texture--it is nowhere near solid enough to use in a bonbon; I would guess that it would take double the amount of white chocolate to make it acceptable. Although I have not tried that option, I am fairly certain that we would once more be dealing with a faint pistachio taste. Oh well, it was an interesting possibility....

But my issue is that I already have some good and completely smooth pistachio paste, from which I now want to make pistachio praline paste--and from that, pistachio gianduja. It seems logical to me that I should make a caramel (just the caramelized sugar, not a full-fledged caramel with cream) and add it to the paste, but I'm not sure what will happen because I can't think of any analogous techniques. I am guessing that heating the pistachio paste may help prevent the immediate seizing of the caramel. Obviously experimentation is in order. Any insights would be appreciated.

Did you use any glucose? If not, that's what I would try.

Just a word of caution: It may well be my faulty technique, but several times (though not every time) when I made butterscotch (cooking brown sugar with the butter, rather than adding the butter later as is usual with a caramel), the finished product looked fine for a while but then separated into a brown sugar and a butter layer, and nothing I did successfully recombined them. So I would suggest you leave yourself some extra time to deal with any "mishaps."

I'm interested in trying that flavor, but don't see anywhere to order it. How would you suggest it be made? Make a caramel and add that to some pistachio paste?

Even though the Italian pastry chef across the street from me insists that gianduja is made only with milk chocolate, I have found I like the taste made with dark much better. Originally I bought bars of gianduja from Valrhona and melted them gently, but quickly discovered it is as much a pain to melt them (keeping them in temper) as it is make the stuff from scratch (not to mention the cost of having Valrhona make the gianduja). So I bought Cacao Barry's hazelnut praline paste and followed Peter Greweling's 1:1 (chocolate, hazelnut praline paste) recipe, which results in the equivalent of 1:1:1 (chocolate, hazelnuts, sugar). One time I accidentally purchased plain hazelnut paste (Cacao Barry) and discovered that I liked the taste of 1:1 dark chocolate to hazelnut paste (no added sugar) much better. Cutting the sugar this much is unorthodox, but it works and I have had no issues. The consistency of the final product depends on the consistency of the hazelnut paste (and how well I have mixed it up), but it firms up enough to cut and not so firm as to endanger guitar wires.

I have read this thread (and the other one on cross-contamination) with interest. I am making an effort to be more aware of sanitary principles. From other sites I am aware of the forbidding of the use of sponges (in favor, I suppose, of the cloths that Lisa Shock mentioned earlier). Indeed sponges are expressly forbidden in the food handling laws of my state. Having mixed up a bleach and water solution and given up my sponges for a day in favor of a cotton cloth, I have to ask why the negative views of sponges. If I soak a sponge and a cloth in bleach water for equal amounts of time (I have read that several minutes is best), what is the difference? I very much prefer sponges, especially those with the hard plastic back that is great for stuck-on bits. I will be interested in any insights.

Sounds like a good idea. Thanks. I just spent half an hour looking for the where missing magnets had landed, so I am motivated to solve the issue.

I'm adding to this old topic because I am having a new issue with some magnetic molds. The ones with plastic (as opposed to metal) bottoms are in some cases losing their magnets--that is, some of the magnets come out when I am removing the bottom (and stick to the magnets embedded in the bottom). I am concerned that I am going to misplace these loose magnets. There is no brand name on the molds, but I bought them at J.B. Prince (those of you who make chocolates would readily recognize them: one round with scalloped edges, the other rectangular with notched edges). Is there a food-safe glue that could be used to restick the magnets into the top part of the mold? Thanks for any advice.

This is a very relevant topic for me right now as my state allows home kitchens to be approved for the making of food items for sale after an inspection, and I just had my first conversation with the inspector a day or so ago. I must confess I had not really thought of all the contamination there might be, but he certainly brought it to my mind (cleaning surfaces with a bleach and water solution, for example). The alcohol wipes mentioned in this thread sound as if they might do the trick. Reflecting on what @dcarch said, I am the first to approve of a sanitary place for food prep--and I am going to have to teach myself some new and demanding procedures if I want to go through with this inspection--but aren't many sanitation procedures an illusion? After utensils are removed from a sanitizing cycle of a dishwasher or after a counter is wiped down with a bleach solution, how many seconds pass before they are subject to recontamination from what floats through the air of a typical kitchen?

Yes, I do that, overnight at least. I think with the recent apple caramels, I left them for two nights. I'm thinking that once the skin forms, Kerry's idea of spraying with cocoa butter would allow a stronger barrier to form. I probably wouldn't go through the lengthy process of setting up the airbrush for that (I'm working in a quite small space) but would use a paintbrush or even a small spoon instead. The firmed-up cocoa butter looks terrible, but nobody would see it eventually.

Yes, the leaking is from the cap (that is, the eventual bottom). It's not much but enough to make them stick to the containers where they are stored. I've tried the acetate sheet for sealing chocolates in the past, even thought it was the Holy Grail from a European video I saw, but when I did it, it made a huge mess and ended up with a thin layer of chocolate over the entire surface of the mold. Presently I have squares of acetate at the ready when sealing chocolates for the times when I have a little ganache sticking up that needs to be covered with chocolate. Maybe I could try something like that. The problem, of course, is that the little holes are too small to see.

If you think about the melted cocoa butter that is often called for in ganaches, it eventually hardens and thus firms up the ganache. The silk just isn't quite melted. I routinely use it when a ganache recipe calls for melted cocoa butter.

Thanks very much for your kind words.

I'll give that a try. And while I was just working out (have to do something to get rid of the results of those defective bonbons), I thought of EZtemper silk. That would certainly thicken up the caramel, but (my theory goes) the thickening wouldn't happen until after the caramel had been piped. Your thoughts?

I've found some random postings on this topic but not what I need. I make several different caramel fillings. One is Notter's salted caramel, and I've not had leaking issues with that. Another is a caramelized pineapple recipe from Wybauw, which used to leak quite badly until I started using Kerry Beal's recipe that calls for adding some chocolate. But my apple caramel does tend to leak and I am seeking any hints for solving the issue. I cook the caramel to 234-235F/112-113C. Cooking it much longer makes it quite difficult to pipe into molds later. So next time I'm going to cook it another degree or two and see if it's still pipeable. Last time I tried a technique I saw online: closing the chocolates and scraping in the usual way, then spreading another layer of chocolate and scraping again. This double layer seemed to help (not sure since there are so many possible factors), but still left me with perhaps 6-7 slightly leaky bonbons out of a 40+ total. I also passed a hair dryer over the filled molds before closing them to try to meld the bottom to the rest of the shell. I don't know whether that helped or not. I don't want to add chocolate as I think it would muddy the apple flavor too much. What are the thoughts on adding cocoa butter? One other bit of info: I make lots of other (non-caramel) fillings that are quite soft but have never had any leaking with those. It's just the caramels where the problem occurs. Any ideas would be most welcome.

Who knows, you may inspire a young entrepreneur out there to write a new app: WebImpulseSealer or perhaps a more inventive name. Should be wildly popular with eGullet members facing their annual clean-out-the-kitchen-junk struggle.

A definite possibility. My new impulse sealer arrives today and the bags (3 mil thick, recommended for freezing) are on their way, so I'll be experimenting. When I froze the individual chocolates, I put them on quarter-sheet pans, wrapped them in plastic wrap, then into bag.