paulraphael

Ok, I just did a taste test. I figured out a way to blind test myself. Did two rounds of triangle testing, each with two samples doubled (so I tasted 7 samples in each round and wrote down my impressions). First impression: blind taste tests mess with you. In round 1, sample E tasted "overwhelmingly sweet. couldn't taste other flavors." Sample F tasted "very fresh dairy flavors. illusion of vanilla." E and F turned out to be from the same batch. So take my impressions with a grain of rock salt. Overall, comparing my notes from the two rounds, the winner was 75°C at 30 minutes. It had the most natural dairy flavor. Cooking a full batch sous-vide, I'd probably increase to 40 minutes, since it takes a while for the mix to come up to temperature. Coincidentally, this is the temperature Jeni Britton uses, and she uses her pasteurization to denature the milk proteins for emulsification. She cooks for 2 hours, but I believe her goal is a more cooked flavor. This test revealed very minor differences. I'm going to enlist my girlfriend for another round of this. Her palate might be a bit better than mine. Details: this was a 15% milkfat mix, 2 yolks per quart, 0.2% stabilizer. 10% nonfat milk solids, 25% total nonfat solids. Milk and cream were from pasture-fed cows, sold by the 'natural by nature' coop.

Well, it sounds tasty. I suspect the issue is the coconut oil. It's a really tricky fat to have in a frozen dessert, just like cocoa butter. It's 100% solid at any ice cream temperature, unlike milk fat, which is in so many different phases that between 5°C and -10°C you're just increasing the proportion of solid fat. I use coconut oil to make homemade magic shell. Would be interesting indeed to try that in a paco jet.

Sorry to hear. No experience with that. I suspect the problem is the opposite of drying out—it's taken on moisture and glued itself together. Atomized glucose is spray-dried glucose syrup, and so I'd expect it to readily take on humidity from the air. Or from from whatever additional water you add. Not sure what you could do besides physically grind it up, and maybe dry it in a warm oven. Or else convert it back into syrup and use it that way. Let us know if you take one of Laiskonis's classes at ICE. He's a great teacher.

It's not at all non-stick. I've had calphalon stuff since before it was calphalon. It sticks about the same as stainless steel, which is to say, you're dependent on cooking technique to keep it from sticking. It's not as good a cooking surface as stainless. But the thick aluminum cooks well for lots of things; it's conductive and pretty quick. I really like my 20+ year old 5qt anodized rondeau. It's beat to hell but does a lot of things well, and the surface is unimportant. I wouldn't get a nonstick soup pot under any circumstances.

You don't need a circulator to reheat something cooked s.v. ... just a thermometer. Heat a big pot of water to approximately the right temperature (err on the low side) and toss in the bagged food. If the food is thick it can take a while, so you may need to turn on the heat briefly a couple of times. But often the thermal mass of a stockpot of water is enough. You just need to warm the food to the center. Follow by searing if that's would you'd normally do. Edited to add: I sometimes do this at home just because the circulator might be busy or I might not be in the mood to set it up. My hot tap water is pretty consistently 53°C. This is great for reheating a lot of things without any need for a thermometer. The searing step adds some additional heat.

Anyone in the NYC area want to participate in a taste test? I've prepared 5 identical batches which will be cooked differently: 72C 60 minutes 75C 30 minutes 60 minutes 80C 15 minutes 30 minutes No flavorings. Made with organic milk from pasture-raised cows. Right now I'm testing for flavor only; I can fine-tune texture with other variables. I only have facilities to spin one batch of ice cream in a 24 hour period, so this will be a tasting of unspun mix. If anyone wants to come over in the next couple of days to offer an opinion, I'll sweeten the deal with cocktails.

That's become a standard for us too. The local food coop carries a brand that comes boneless and pre-vacuum packed. Couldn't be easier.

Interesting. I think I've only had one leak ever. If you decide to double-bag, is there any reason you could reuse the outer bag indefinitely? It's only coming in contact with food if the inner bag fails.

Thanks for the link on dextrose. The interesting tidbit in there is that perceived sweetness is different in ice cream than in other contexts (no reason given). But their tests showed that the usual figure of dextrose being 0.7 times as sweet as sucrose isn't correct; in ice cream it's more like 0.83%. Meaning, for equivalent sweetness, you need 1.2 times as much dextrose. Less the most of us assumed. The data on people's preferences don't strike me as very useful. These are in situations where all else is kept equal, so people were judging based on sweetness and rate of melting and body ... all qualities that can be controlled by other means. Here are the conclusions with some of my annotations: The following conclusions apply to ice creams sweetened with sucrose as compared with those in which one-fourth of the sucrose is replaced with dextrose. 1. Consumer tests show that hydrous dextrose has a sweetening value which is 83 percent as effective as sucrose in ice creams, and anhydrous dextrose has a value equal to sucrose. [interesting!] 2. The use of dextrose in ice cream does not affect the time to freeze and whip the mix. 3. When 25 percent of the sucrose is replaced with dextrose the drawing temperature will be approximately one degree lower. 4. Dextrose imparts as desirable flavor and body to batch- frozen ice cream as does sucrose. When dextrose ice cream is frozen on the Vogt continuous freezer, the stabilizer content must be reduced in order to avoid a sticky body. [so, no significant flavor difference. Possible differences in body can be compensated for by reducing stabilizing ingredients] 5. Dextrose ice cream melts slightly faster at room temperature, which possibly accounts for the greater refreshing qualities of high- fat ice creams having one- fourth of the sucrose replaced with dextrose. [This is the expected result of the lower freezing point and increased scoopability] 6. Dipping the dextrose ice cream at lower temperatures than the sucrose ice cream helps to minimize dipping losses. 7. Dextrose imparts slightly more color to the mix, slightly lowers the pH, and decreases mix viscosity.

If you're in a town with a Whole Foods, they often have a small selection of Valhrona and Callebaut chocolates in bulk. Prices are decent and of course you don't have to deal with shipping.

Yes, you can, although with the drawback that you're actually making a very high-sugar ice cream. Dextrose is both less sweet than table sugar, and has nearly double the freezing point suppression. So your final blend that gives the hardness and the sweetness you like will be a much lower sugar ice cream. It's possible that the formula with trehalose, just by adding a lot of extra nonfat solids, is improving the texture. But I'd bet that milk solids would accomplish this more effectively. The proteins have emulsifying capacity, and the lactose has exceptional water binding capacity.

That's cool ... definitely an odd one. I bet the bread starch makes significant stabilizing and solids contributions. You might be able to cut down on gums and egg and any added dry milk. It must be begging for some salted butter.

Interestingly, this exact question with trehalose has been addressed (it's the only trehalose / ice cream article I've seen so far): http://onlinelibrary.wiley.com/doi/10.1111/j.1365-2621.2006.01484.x/full It suggests that this sugar is not what's responsible for the lack of iciness.

I've never seen trehalose used in ice cream before. Does trehalose have water binding properties that you're aware of? Does it come in syrup form? Usually alternate sugars are used for their increased freezing point suppression. You can predict this quality with the molecular weight of the sugar; the lower the number more it depresses freezing point. Trehalose is a disaccharide like sucrose, and has a molecular weight that's very similar. So you wouldn't predict any freezing point effect. The only sugar I know that has a significant effect on iciness and texture is trimoline. It has pretty strong water binding properties (and a low molecular weight, so it's useful generally). It's pretty typical to use this for 10-20% of the total sugar weight. It's a little bit sweeter than sucrose by weight, so between sucrose, dextrose, and trimoline, you can fine tune the sweetness and the freezing point independently. For ice crystal control I use a blend of hydrocolloids. I don't get a noticeable increase in iciness over the course of two weeks. But ... I'm working on getting the ice cream smoother on day one. The holy grail in texture is (sad to say) industrial ice cream, and mine isn't that smooth. My KA ice cream maker can freeze a batch in around 15 minutes, which is pretty quick ... I won't be able to afford anything that goes faster. So that's a small disadvantage over, say, a high end Carpiggiani machine that works in 5 or 6 minutes. But the other industrial advantages are a blast freezer (-40 or lower, to flash harden the ice cream), and homogenization of the mix (Jo, you are the victor here!) I'm working on how to get the best flavor textural results possible without high end equipment. Presumably if Santa brings me a Carpigiani machine or a homogenizer, things will only get better, but I'm enjoying the challenge of seeing how far things can be pushed in their absence. It's amazing how there is to learn at every turn.

I like the magnetic ones. They're easy to use and easy to clean. And you can trim them for a perfect fit. They're a bit heavy, but I only hear this complaint from pros who have to transport a whole lot of knives. I usually just have three or four in my knife roll and the weight isn't noticeable.

What's the advantage of the KA heat mixer bowl over a laboratory magnetic hot plate? I've seen ones with thermostats for under $200.

I've already searched for an attachment designed for it. No hits. BTW, in the homogenizer world, the rotor-stator is called a generator (don't ask me why). Seems like homogenizers today are like immersion circulators were 5 years ago. Priced for the lab market. An attachment for a Bamix would an interesting project for someone with access to a CNC machine. Or maybe we can convince Anova to get to work ...

If anyone has a Bamix (I don't) I'm wondering if the whisk attachment would make a reasonable poor man's homogenizer. Some models go up to to 17,000 rpms.

The cooking issues guys say they circulate detergent water.

I'd be interested to know if there's an effect on final texture if you homogenize at the beginning of cooking rather than at the end. Maybe I can commission a batch.

There are a lot of issues with nonstick pans, but it's beyond my imagination why plastic would be one of them. But yeah, unless you're doing lots of egg cookery, or delicate fish with the skin on, there isn't much justification for nonstick. a metal surface almost always gives better results.

It's all based on PTFE and it's all disposable. If you really need a nonstick pan, best to get a cheap one. Restaurant stores are a safe bet.

I'm sure someone will volunteer to buy the O.P.'s circulator

Dave Arnold and Nils Sorensen on Ziplocs for sous-vide: The advantages of the Ziploc are: you don’t need to buy a vacuumfood can be bagged hotfood can be removed from the bag and re-bagged easilythe process is very gentle on foods and doesn’t change food textures the way vacuum bagging canit’s just as effective for cooking as vacuum bagging for most itemsThe disadvantages of the Ziploc are: not as convenient for bagging a lot of items as the vacuum machineZiplocs cost more than vacuum bagsdoesn’t provide some vacuum benefits –fast marination, extended storage, oxygen removal.Dave's summary, which mirrors my experience: "While I love a commercial vacuum machine, about 90% of what a cook wants to accomplish with low temperature cooking can be achieved without a vacuum machine. When Nils was at restaurant Aquavit he did a lot of low-temperature work with a circulator, but didn’t have a vacuum machine. Back then restaurants weren’t required to have a HACCP plan; he didn’t have a commerical vacuum because they cost too much. Today many home cooks use the Food Saver vacuum for low temp. I don’t use my Food Saver any more. I use Ziploc bags, without a vacuum. I find Ziplocs easier than the Food Saver – I don’t have to hunt down the special bags, I can easily bag sauces (a pain with the Food Saver), I can bag hot foods (foods to be vacuumed need to be cold – more on that in the next primer installment). My Food Saver has been relegated to potato-chip-bag-resealed." At cookingissues.com

Preparation with ziploc bags is pretty easy, and in many cases preferable to vacuum sealing. And there's no reason they can't be used for cook/chill. I do it all the time. They're a bit pricey, but some people wash them in the dishwasher and reuse.