Why was there not enough foam in my garlic foam with soy lecithin?

Question

This was my first attempt at making a foam using soy lecithin. I used 3 garlic cloves, 2/3 cup water, 2/3 cup milk. Then i used an immersion blender. I got a bit of foam on top but there wasnt a lot of it. It felt like a waste of a lot of milk. How much foam should I be expecting?

For now, I put the foamy mixture in the fridge, is there a way to salvage and get more foam?

Asked by moorecats

Answer

Just an idea... I've had problems making foam because of hard/basic tap water (a lot of chalk in the water) - making frape though, not garlic foam:) Foam will more easily form in soft water as you can easily test with a piece of soap. If you have hard tap water you could try using boiled water (some of the chalk in the water will react and leave a residue on the bottom of the pot) or bottled water with pH 7 (neutral). Another idea would be to add just enough acid for neutralisation but I imagine that could be a bit tricky and you'd risk the milk curdling so I wouldn't recommend it.

Answered by Heidi Larsen

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Does tiramisu firm up in the fridge?

Question

I am making my first tiramisu, using this recipe from Gourmet (with high ratings on Epicurious). My mascarpone mixture looks terribly soft to me.

As per recipe, I foamed 4 yolks with 80 ml sherry (I had no Marsala) and 95 g sugar at 55°C. The yolks were from recently bought M-sized eggs, there were no L-size in the supermarket. The volume increased a lot, but the foam itself was runny. I mixed in the 450 g mascarpone (the egg mass was still warmish), and it seemed to dissolve (I hope I didn't melt it). The result was still foamy and runny. Then I folded in the 240 g whipped cream. The final consistency is similar to egg whites beaten to stiff peaks. It is a foam, and not runny, but very aerated, and I suspect that, if left on a heap (instead of a bowl), it will flow flat over time. It is very unlike the cream layer in tiramisu I've had before.

Is this normal? Will the cream harden in the fridge? Will the ladyfingers soak up some moisture? (They are coffee-dipped in this recipe). Or should I put in some gelatine to make sure it will keep shape? Or some other thickener? I have xanthan, but don't know how to incorporate it, the mass won't survive a mixer on full speed, and it will clump if not perfectly dispersed.

Asked by rumtscho

Answer

Your recipe doesn't specify 55°C, and I'd be surprised if 5–8 minutes over barely simmering water only gets that hot. Indeed, checking for sources:

• McGee, in On Food and Cooking, says:

  When the temperature reaches 120°F/50°C, high enough to unfold some of the yolk proteins, the mix thickens, traps air more efficiently, and begins to expand. As the proteins continue to unfold and then bond to each other, the foam rises into fluffy mounds. The key to maximally light zabaglione is to stop the heating just when the foam teeters on the cusp between liquid and solid. Further cooking will produce a stiffer, denser, eventually tough sponge as the proteins over-coagulate

  so that leads to the conclusion that 55°C wasn't hot enough, as it hadn't yet reached "the cusp between liquid and solid".

• Hans-Dieter Belitz, Werner Grosch, and Peter Schieberle say in Food Chemistry:

  Egg yolk can be whipped into stable foam only at higher temperatures (optimum 72°C), the volume increasing about sixfold in the process. Above the critical temperature, the volume falls and the proteins coagulate. The protein coagulation is prevented by reducing the pH value, e.g., by the addition of acetic acid. This effect is used in the production of highly stable sauces

  so that'd imply you want 72°C, or maybe higher due to the acid (wine) present. As a side benefit, that'd also pasteurize the eggs.

In summary, I think you should have cooked it hotter.

I doubt it is going to firm much in the fridge, hopefully it is stable enough to not further liquify.

Answered by derobert

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Why did my “goat cheese espuma” flop?

Question

I recently got myself an iSi Creative Whip and have been having a lot of fun playing around with it. Tonight I tried one of iSi's recipes, which uses the following ingredients:

• 250 g goat cheese
• 125 g sour cream
• 125 mL cream
• 1-2 tbsp olive oil

Preparation is basically to purée the goat cheese, sour cream, and oil, mix in the cream, strain it through a sieve, load it into the whipper, then charge and cool it.

At the denouement, I was greeted with a brief but ominous fizzle followed by an even briefer splatter of yogurt-like liquid, very much like the explosion of snot one witnesses after somebody sneezes a little too hard. After clearing the cheese blobs from my shirt and hair, I proceeded to scrape the remains (which was in fact the majority of what went in there to begin with) with a rubber spatula and spread it on some crisp toast; it was delicious in spite of not even being remotely close to an espuma.

I'm well aware, as the manual makes sure to mention about half a dozen times, that the whipper will fail to perform any actual whipping if the fluid inside is too thick or viscous. I was quite skeptical myself, before charging it in the first place, but until now I haven't really tested the limits of this thing, and I figured, if I was able to strain it through the sieve (with much mashing, I might add) then it would be whippable.

So I already know, superficially, why this failed, but that only leads me to a deeper why which I have been unable to answer myself: Why did this happen with one of iSi's own recipes, found in the very recipe book that is included in the same box as the whipper itself? I have to assume that iSi knows what they're doing and it was me that screwed up; but how? What did I do wrong and how could I have fixed it?

Some possible avenues of investigation:

• There are a great many different types of goat cheese available; I used the standard soft/unripened type, but there are also goat cheese "spreads" that are probably less rich. Perhaps the recipe was actually referring to one of these?

• I used ordinary (14%) sour cream; perhaps the fat content was too high and the recipe intended for light or even fat-free sour cream?

• I had a lot of trouble actually puréeing the mixture; using a blender, I found that the mixture didn't really move around much, so I had to keep scraping it back into the center so that it would hit the blade. The recipe actually says to use a blender or food processor but I assumed that a blender would be better. Should I have used a food processor instead, or maybe even a stick blender? Would any of this have actually made any difference, given that the consistency of the final mixture was very smooth (albeit thick)?

Are any of these likely to be the root cause? Is there anything else I might be overlooking?

Answer

Goat Cheese is dry compared to many other cheeses. We make a goat cheese pizza but have to moisten the shredded goat cheese with goat milk into a kind of slurry. Very low in lactose and tastes good but it doesnt even melt much because it is so dry. Probably lower in fat too I would guess. If your espuma is too dry try adding more goat milk to the mixture until it just moves in the blender. AGuyNamedBob dot com

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Frothing Milk: Variations by Milk Type?

Question

I froth my milk using the steam wand on my espresso machine. With a national-brand organic whole milk, I am able to get a perfect micro foam nearly 100% of the time. However, when I instead use a local, grass-fed, organic whole milk (whose flavor I prefer to the national brand), I am only able to produce a perfect micro foam about 20% of the time. What could be causing this? Could it be differences in the fat content? (They are both labeled "whole".) Does it have something to do with the fact that the national brand was likely from grain/corn-fed cows, whereas the local brand is grass-fed?

Update: The local milk is homogenized and pasteurized. It does not say anything about ultra-pasteurization (i.e., HTST vs. ESL). The "national brand" milk is homogenized and apparently comes in both "pasteurized" and "ultra-pasteurized" forms. I'm not sure which one I usually get, but if I had to guess I'd say it's ultra-pasteurized (i.e., ultra-heat treated) because the national brand usually has a sell-by date at least a week after the local milk's expiration. According to their nutrition labels, both have the exact same nutritional content except:

• Sugar (per cup)
  National: 11g
  Local: 12g
• Cholesterol (per cup)
  National: 30mg
  Local: 35mg
• Vitamin C (% of Daily Value per cup)
  National: 0%
  Local: 4%
• Vitamin A (% of Daily Value per cup)
  National: 4%
  Local: 6%

Protein content is reported as identical.

Update #2: As I mentioned in a comment to TFD's answer, I let the local milk age for several days and now I seem to be getting better results (although I am now at the cusp of its sell-by date). Perhaps there is some psychological effect going on and I am paying more attention to my technique now, though. If in fact this success is due to the aging, can anyone explain why? What happens over time that allows the milk to froth better?

Answer

Let your milk age a bit; a day or two extra in the fridge should fix the problem.
Your local milk is too fresh.

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