paulraphael

I spent some time with this book when it first came out and found quite a few head-scratchers that I suspect are editing problems. I don't remember that exact formula. Have you worked out the math and then analyzed the results, to see if they match the intention?

Cheap alloy aluminum pans sit on 30,000 btu/hr burners in restaurants all day long. The worst thing that ever happens is they warp. I'd maybe worry if we were talking about magnesium.

I'd be interested in people's experience with surface treatments. I have an old aluminum griddle that I've seasoned like cast iron, with no special surface treatment. As could be expected, the seasoning flakes off pretty easily. A griddle gets rougher treatment than a pizza steel, but I'd still be curious about ways to improve the durability, either physical or chemical.

Certainly dextrose. Not sure about other non-sugar or non-caloric options. I've never done battle with sweetener crystallization.

Has anyone found a 1/2" aluminum slab for pizza, or priced one from a metal yard? Seems like a good idea. You'd need the slab to be at least thick as your steel (ideally thicker, if you're trying to match the heat capacity) but it would still be lighter. You'd want to season the thing like cast iron, to blacken it and increase its emissivity. Kenji's test of of copper vs. steel showed the copper to be inferior despite much higher conductivity. Uncharacteristically, Kenji made a dubious analysis of what was going on, but if you dig into the comments thread, you'll find some physics-minded people who correctly posit that the difference is in emissivity, and that a pizza steel / stone / oven deck heats primarily by radiation and not by conduction.

I don't believe it's about stabilizers. I think it's combination of cocoa butter (hardening the fats) and extra glucose (softening the frozen portion).

Ok. Here's a paper on using erythritol in ice cream. It says the hardness comes from crystallization of the the erythritol itself; the freezing point depression factor is actually three times stronger than that of sucrose. The suggested compensations are to combine with other sugar alcohols (sorbitol, sucralose, polydextrose). The complete sugar reduction is achieved by taking out the crystallisation inhibiting glucose syrup. However, due to erythritol’s strong crystallisation behaviour, a crystallisation inhibitor is indispensable. Several options from the polyol range were tested in the frame of the project. It was found that sorbitol, maltitol, xylitol and their mixtures, all perform quite well alongside erythritol. It was also discovered that all three indeed soften the ice cream structure. This creates a great toolbox where the polyol pair can be varied to modify product hardness and creaminess. The actual second polyol can be chosen according to individual preference as they all will harmonise with erythritol. Texture as well as sensory analysis revealed that the preferred polyol ratio should be in a range of three parts erythritol to two parts of the second polyol.

I don't know what's going on in your particular formula, but the inverse relationship between freezing point depression and molecular mass isn't just some pet theory of mine. It's a basic principle in chemistry. Chemists actually use it to calculate the molecular mass of unknown chemicals in solution.

Yes, it's exactly what I mean. I like chocolate ice cream with a strong chocolate flavor, which means using lots of chocolate. And this means adding lots of cocoa butter. It can make the ice cream too hard. If you take the usual steps with sugars to soften the ice cream, you can get a kind pudding-like texture that I'm not thrilled with.

I think there's a long, long road between "I don't like bad coffee" and "I'm a coffee snob." There's plenty of perfectly adequate, inoffensive tasting coffee will wake you up in the morning and put a smile on your face, but that won't have the qualities to satisfy an aficionado. Last month I was listening to a podcast by Matt Perger, a former world champion barista and roaster with many opinions (I may be showing my had here, regarding the snob continuum ...). He made an interesting point: tea, wine and beer have histories of many thousands of years, and for most of this time people were concerned with how to make them all taste good. Coffee has only been a beverage for a few hundred years, and almost all the study into making it taste good came in the last fifty. You could even argue that most of it is from the last 20. So coffee snobbery (or enthusiasm, or whatever you want to call it) has only even been an aspiration for a short while. It's new club, and it's evolving quickly. If you're intrigued, be sure to join before climate change wipes out all the good farms.

Sherry vinegars have potential. I concocted a ginger cocktail a few months ago with a bit of pedro ximenez vinegar, and I think it worked pretty well. There are different kinds, with different complexities and balances of sweet/savory/dry/fruity, and with with hints of fruit that range from raisins to pears to peaches.

A pair of heat-mouldable running shoe insoles.

I'm not familiar with pentose or any of its uses in food, but I need to correct what wrote above about sugar alcohols: they tend to have smaller molecules than the more common monosaccharides like glucose and fructose. So they have greater freezing point depression.

Anything dissolved in the water lowers the freezing point. Fat doesn't directly lower the freezing point, but since it doesn't freeze (or at least it doesn't harden to the same degree as water) it softens the ice cream by replacing water that could freeze. We focus on sugars because they have greater powers of freezing point depression than most other ingredients, with the exception of salt and alcohol. This is 100% a property of the size of the molecules. Smaller molecules (quantified as the molecular mass) have greater freezing point depression. This is why glucose and fructose each are more powerful than sucrose, which is a larger molecule made of one of each of the other two. And sugar alcohols, being larger molecules still, are less powerful than sucrose. Proteins are very large, and so are significantly weaker than any sugars. You're dealing with such an unconventionally balanced recipe that we can also look at just in terms of how little water is in there. There isn't enough of it to freeze and properly harden the ice cream.

It used to be made from PVC, which you can spot easily because it smells like a shower curtain. Most home plastic wraps have switched to low density polyethylene, which doesn't cling as well and is more permeable, but which doesn't off-gas and is less likely to leach anything nasty into food. Most commercial cling wraps still use PVC, so if you're watching a pastry chef pull it off of one of those 18" wide rolls, that's probably what you're getting. The biggest concern with cling wrap is the plasticizers that are used to help them cling and to give them the right degree of flexibility. In PVC the most common ones are phthalates, which have known health concerns. Polyethylene itself is inert with regards to food, and if it needs plasticizers at all, they're probably a much more benign crop of chemicals. But we don't really know what if anything is added. Personally I feel pretty safe around saran wrap. I'm not too happy with the idea of wrapping food in PVC and baking it. For what it's worth, BPA is a component in epoxies and polycarbonate. It was never used in flexible plastics like cling wrap.

My understanding is that it's the strong alkaline component of the dishwasher detergent that oxidizes the aluminum. There's definitely a difference between something that's been machine-washed once or twice vs. dozens of times. Sometimes restaurant stores sell used sheet pans for a couple of bucks each, and among them will be ones that were sent through the washer until the aluminum was matte-white, pitted, and coming off in flakes. There's a limit to what you could hope to accomplish on these with some BKF. If you could manage to remove the oxidized aluminum there wouldn't be much of anything left.

I'd think the bigger liability danger would be people doing cook-store techniques without knowing what they're doing. Most home cooks do so much cross-contamination and leave food out for so many hours at the wrong temperatures that it's hard to imagine a circulator adding to anyone's actual peril. In NYC it's the chamber vacuum sealers, not the circulators, that freak out the health dept. They're probably overreacting to something they don't understand, but they require any restaurant with a vacuum machine to implement an HACCP plan. I'd think if the s.v. instructions given by the library just need to advise people to store bags in the fridge for no more than a few days. This and don't cook for more than, say, 2 hours below 131°F. On the one hand it's better to be safe than sorry when it comes to consulting lawyers. On the other hand, especially with topics they don't fully understand, lawyers are likely to be very conservative and just advise against everything.

I wonder if klutziness could be a byproduct of being forced to do things right-handed by bad teachers. Maybe this comes up more for certain generations or demographics. A sinister proposition.

Rental equipment tends to get abused, so I'm thinking that the consumer circulators will have pretty short lifespans. The library should probably budget for replacing the things every few months. The alternative of lending professional circulators probably isn't too appealing, since they tend to be so much bigger and heavier. And they're equally vulnerable to death by drowning. I think it's a great idea, at least as an experiment. I would have loved this. I made my first forays into s.v. with borrowed equipment, but was lucky enough to know people who owned the stuff.

Interesting. I haven't had that kind of luck with sheet pans that have been assaulted by the dishwasher. No sense of the the oxalic acid magic happening with aluminum oxide. Maybe it's a slower reaction than with stainless steel.

Yeah, if you want to nit-pick everything.

FWIW, I've used ziplocs exclusively for the five or six years I've been cooking sous-vide. I noticed that Dave and Nils at cookingissues.com say they use either ziplocs or plastic wrap for most s.v. cooking, relegating their vacuum sealer to other duties (storage, infusions, instant pickling, etc.). I've had one bag leak ever. Now as a precaution, I double-bag for any long cook above 85°C. I think the biggest drawback of ziplocs is that they lose strength as they approach the boiling point. Some other caveats: they're not reliable if you reuse them, they're almost guaranteed to leak if you freeze the contents and then thaw, and you have to get the one's labelled "freezer bag," and that don't have the plastic slider to close them.

Interesting. I've never pulled off this particular kind of alchemy, even with BKF. Maybe you're actually abrading off the oxidized aluminum on the surface?

Yeah, I'm pretty sure that's the case. Last month I visited Michael Laiskonis's chocolate lab at ICE, and just about the only piece of equipment missing from this extremely shiny playground was a mill for grinding cocoa powder. They have a 100-ton hydraulic press to separate the cocoa solids, but nothing to refine them. So if you're wondering what to get them for christmas ...

I'm betting that Askinosie just isn't able to mill the cocoa as finely as the bigger industrial manufacturers. This is likely to be a problem for anyone trying to make chocolate ice cream with single-origin cocoa powders. There just aren't many of them, and they mostly seem to be available from small artisanal chocolate makers, who would likely have lower-powered milling equipment. I wrote to the people at Match Chocolate about this. They advertise SO cocoa powders, and warn in the descriptions that they're milled coarser than industrial cocoas. I asked if they were coarse enough to affect the texture of ice cream, and they said absolutely. They're hoping to upbgrade their equipment at some point, but it doesn't sound like any time soon. This is an issue for me, since I like to feature distinctive main ingredients in my ice creams. I'm much less interested in generic tasting-blends than in pure ingredients with interesting origin flavors. For chocolate, this mostly means using couverture, but this choice comes with a litany of texture challenges from the cocoa butter. I'm planning to start a new round of chocolate ice cream experiments soon. The approach I've been using, which needs a lot of work, is to mix an SO couverture (like Cluizel Villa Gracinda) with a good quality non-SO cocoa (Cluizel or Valrhona). The idea is to get some of the distinctiveness from the couverture, but to not use so much that texture problems are too noticeable. I'd like to switch to 100% SO cocoa powders, but don't know of any right now that are suitable. Callebaut advertises some on their commercial site; I haven't yet figured out how good they are or how to get my hands on them. Also I believe that non-Dutched cocoa would be ideal in ice cream. Unfortunately these aren't so popular with the great better chocolate makers. It would be nice to see some variety here.