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Maximum temperature of hot custard sauces


project

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Have some nice looking scallops, lots of clam juice, dry white Chardonnay wine, mushrooms, flour, butter, milk, whipping cream, eggs, shallots, herbs, and salt and can get some lemons and maybe some Swiss cheese and want to work again on

'Coquilles St. Jacques Parisienne'

e.g., as in

http://forums.egullet.org/index.php?showto...ndpost&p=426973

So, make a 'court bouillon' of clam juice, white wine, shallots, mushrooms, a bouquet garni, poach the scallops a little and strain and set aside in a bowl set in ice, reduce the stock, add to a roux, add milk and whipping cream, combine with egg yolks, heat, add lemon juice and salt to taste, combine with scallops, heat, serve, maybe after a few gratings of Swiss cheese on top mostly for color and maybe with some browning under a broiler -- maybe with other seafood in the mix, maybe with ....

So, yes, the sauce is a 'volute' until add the egg yolks at which time maybe it's a 'Parisienne'. Whatever, it's a hot custard sauce and not the only one.

So, here's an issue and the question: Consider heating the sauce after adding the egg yolks. If simmer or boil the sauce, as is sometimes suggested, then, even with constant whipping, the sauce will likely separate with any future warming or handling. The sauce is very 'unstable'. When the sauce 'separates', can see transparent liquid butter fat and some signs of 'coagulation' in the rest of the sauce and suggestions of egg that got too hot.

So, instead of boiling, am considering heating only to a measured temperature, maybe 140 F, maybe 170 F.

This problem should be fairly general for 'warm custard' sauces: How much heating to keep the sauce stable?

Have any good information for an answer?

What would be the right food and wine to go with

R. Strauss's 'Ein Heldenleben'?

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  • 1 month later...

Okay, Dave, thanks for the 160 F!

I tried it!

The trials need to continue, but so far your 160 F is a NICE improvement!

I used the 160 F twice:

First, I poached the scallops only until the court bouillon temperature was 160 F. That worked GREAT. By far the best texture of the scallops I've had with this dish. So, don't boil the scallops; don't even simmer the scallops; don't even think about it. Instead, stand there, apply heat slowly, stir gently but often to keep the temperature uniform, use a good thermometer, measure temperature often, and at 160 F QUIT. Dump the pot contents into a colander set in a bowl and then dump the colander contents into a stainless steel bowl set in a bowl of ice.

Strain the liquid under the colander and dump the strainer contents into the bowl with the scallops. With the strained liquid, continue with the reduction step.

For the poaching, I use an old 5 quart Farberware pot. Then I use that pot again for the reduction.

Then when the reduction is done, I dump the boiling reduced court bouillon into the bubbling roux all at once, whip vigorously, add the milk, whip vigorously, and remove from heat.

Then I add the whipping cream and whip.

NOW the sauce is cool enough so that can just add the egg yolks all at once. Whip.

Measure temperature and heat gently with constant whipping to 160 F and then REMOVE from heat.

Add the salt and lemon juice to taste.

With constant stirring and gentle heat, heat back to, say, 160 F.

Then combine with the scallops and, with gentle heat and constant, gentle mixing, heat back to 160 F and serve.

This way the sauce is stable. That is, the egg yolks are not overcooked and do not cause the fat in the sauce to separate out.

The 160 F is hot enough to serve.

The egg yolks give the sauce a nicer pale yellow color, And most important the yolks give the sauce a special and attractive texture.

The condition of the sauce after reheating in my microwave oven is also improved, but I am still working on making that better.

For serving another day, one candidate tactic is to store the scallops and the sauce separately, heat the sauce in a sauce pan, add the scallops, heat with mixing, and then serve.

What would be the right food and wine to go with

R. Strauss's 'Ein Heldenleben'?

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Hi,

I normally cook a sabayon to 180 degrees on high heat with rapid stirring before removing from the heat.

Creme anglaise is normally cooked to 175 to 180 degrees.

I'm not sure that egg yolks are fully cooked at 160 degrees. imho, sabayon based sauces normally begin to break because of undercooking. The break occurs when the sauce sits. This also fits the description of the separation in the first sauce.

Overcooking breaks the sauce in a different way with the eggs turning hard and the fats and liquids rapidly separating.

Tim

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It is clear, including from your post, that until the recent trial using 160 F all the years I did that dish I was overcooking the egg yolks. E.g., when sitting while hot, the sauce would separate quickly.

Cooking to 160 F, the sauce didn't separate while standing. It didn't separate while reheating except in some spots that apparently got too hot in the microwave. I heated maybe 10 ounces by weight (will measure next time) in a serving dish for 10 minutes at 20% power and got no separation but also not enough heating -- some of the scallops were still a bit below room temperature! Then 6 minutes at 20% power, rotating the dish, and 6 more minutes at 20% power caused some separation at some spots that got too hot and, still, not quite enough heating of the rest.

So, for reheating, the dish needs work. One idea I want to try is just to keep the sauce and poached scallops separate, heat the sauce in a sauce pan where can keep whipping it to keep the temperature uniform, the add the scallops, heat with constant mixing, and see if that works.

I have wondered: Maybe the sauce would be MORE stable if heated to 170 F or some such higher temperature, much less than 212 F. Heated to 160 F the texture is nice; maybe at some higher temperatures the texture would be still better. "More scallop trials, Ma!".

Thanks for your input.

What would be the right food and wine to go with

R. Strauss's 'Ein Heldenleben'?

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The setting and curdling temp for custards depends on a few factors. The ones I've figured out are the concentration of egg yolks (the more yolks per quart of what you're making, the lower the set point and the overcooking point), and the presence of certain starches. Flour, and also probably corn starch, in small quantities will prevent most custards from curdling at any temperature. I haven't tried this, but i've been told that a fraction of a percent of starch can allow you to boil a custard.

I make my ice creams with as few as two egg yolks per quart; these set up a little over 180F. That would be way too hot if there were 6 yolks per quart. i'm guessing that for that number 160 would be closer to ideal.

Notes from the underbelly

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All interesting. My usual ice cream base uses 6 yolks per quart. I suppose one of these days I should make some tests for myself and ruin a few custards just to see how hot it can go, but I've also found that, if I do it without a thermometer just going by consistency and then check the temperature, I'm still around 160 F.

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The setting and curdling temp for custards depends on a few factors. The ones I've figured out are the concentration of egg yolks (the more yolks per quart of what you're making, the lower the set point and the overcooking point), and the presence of certain starches. Flour, and also probably corn starch, in small quantities will prevent most custards from curdling at any temperature. I haven't tried this, but i've been told that a fraction of a percent of starch can allow you to boil a custard.

I make my ice creams with as few as two egg yolks per quart; these set up a little over 180F. That would be way too hot if there were 6 yolks per quart. i'm guessing that for that number 160 would be closer to ideal.

Hi,

Paul is correct in that custard sauces with flour may be boiled without overcooking. The number of eggs and other ingredients are not relevant until the eggs are properly cooked and this requires 180 degrees no matter the mix or amount.

My point is that almost all custard or sabayon sauce separation is caused by undercooking the eggs. Undercooked custards separate quickly when put on hot food. They also separate slowly when allowed to cool. In both cases the emulsion breaks into a pooling of butter and a separate pool of liquid from the eggs.

Actually, it is clear that the term overcooking is being misconstrued. Overcooking a sabayon (almost 80% water) requires a temp way in excess of 180 degrees. Cook to over 190 and the eggs immediately harden with the butter immediately separated. The overcooking causes immediate and rapid separation and I mean within a few seconds. You can rescue an overcooked/scrambled custard and remake it by straining the mix and beginning again with fresh eggs and use the same butter.

If the eggs do not stand in the strainer, in fact they have not been cooked and have separated due to a break in the emulsion, not do to being overcooked.. This is being clearly described by Project - undercooking.

When I cook a sabayon, I take the temp to 180 degrees and the eggs appear to be scrambled; they come together smoothly when whisked off the heat. Eggs cooked in that fashion easily form an emulsion that does not separate when cooled or when placed on hot food.

Any custard that is only "cooked" to 160 degrees does not properly cook the eggs and will slowly separate as it cools or quickly separate on hot food.

Tim

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Okay, I have more trials to do than I guessed!

The recipe is

Court Bouillon: 2 C Chardonnay, 8 ounces fish stock or bottled clam juice, 5 T minced shallots, and some usual suspects among thyme, parsley, bay leaf, pepper. For mushrooms, I just get sliced mushrooms in cans. In this case, for about 12 ounces "net weight", I include the liquid from the mushrooms in the court bouillon.

Scallops: 3 pounds, thawed or frozen. It is easier to overcook the smaller bay scallops than the larger sea scallops.

White Roux: 8 T butter, 10 T flour.

Milk: 1 1/2 C

Whipping Cream: 1 C

Egg Yolks: 4 from Large eggs

Salt, lemon juice to taste.

In a pot of about 5 quarts, poach scallops to 160 F in court bouillon, dump pot contents into a colander set in a bowl of about 3 quarts. Dump colander contents into a bowl of about 3 quarts set in a bowl of ice water. Put the liquid that passed through the colander through a strainer and add strainer contents to scallops.

In the 5 quart point, reduce the strained poaching liquid to 1 1/2 C. If heat is too high, can scorch the liquid.

While the poaching liquid is reduced or nearly so and simmering, warm the milk and in a pot of about 3 quarts make a white roux of the flour and butter. When the roux is bubbling and the poaching liquid simmering, dump the poaching liquid into the roux all at once and whip vigorously. Add the simmering milk at all at once and whip until smooth.

Off heat, add the cream and whip to mix.

Add the egg yolks and whip to mix. Heat with constant whipping to desired temperature. Off heat, add salt and lemon juice, with whipping, to taste.

Add the contents of the bowl with the scallops, along with the mushrooms. mix, heat through to desired temperature, and serve.

So, what sauce volume do we have: 1 1/2 C poaching liquid, 1 1/2 C milk, 1 C cream, plus the 1/2 C butter and the 10 T of flour. So, we have about 5 C total, with quite a lot of flour.

So, we have 1 1/4 quarts of liquid, 'volute', with 4 egg yolks and quite a lot of flour.

In the past, after adding the yolks, I did simmer and whip the sauce. I found that the sauce would not separate if either (A) the temperature was rising and the sauce was being constantly whipped or (B) the temperature was falling. But reheating, say, in a microwave, in an oven, under a boiler, or just in a pot without whipping, the sauce would separate.

Sounds like Tim is saying that I needed to cook the sauce more, that, with all the flour, I should be able to boil the sauce.

Looks like I should try again!

Edited by project (log)

What would be the right food and wine to go with

R. Strauss's 'Ein Heldenleben'?

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In the 5 quart point, reduce the strained poaching liquid to 1 1/2 C. If heat is too high, can scorch the liquid.

While the poaching liquid is reduced or nearly so and simmering, warm the milk and in a pot of about 3 quarts make a white roux of the flour and butter. When the roux is bubbling and the poaching liquid simmering, dump the poaching liquid into the roux all at once and whip vigorously. Add the simmering milk at all at once and whip until smooth.

Add the egg yolks and whip to mix. Heat with constant whipping to desired temperature. Off heat, add salt and lemon juice, with whipping, to taste.

Project,

The recipe tells you to heat the scallops to 160 degrees. The scallops are heated to an internal temp of 160 in poaching water. That means water north of 185 degrees.

The phrases, "reduce the strained poaching liquid", "the roux is bubbling and the poaching liquid simmering", "add the simmering milk" all mean that the temperature of the liquid is somewhere between 185 degrees and 210 degrees.

Yes, all that flour will allow you to fully heat and cook those eggs. Follow the recipe and you will be fine.

Tim

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Uh, Tim, uh, at this point it's mostly my recipe! I don't have anyone else to blame! All the stuff on temperature is just from this thread and my trials and guesses. The books I have on French cooking -- Child, Diat, Pepin, etc. -- make it sound like France still has yet to discover thermometers! Similarly for timers! pH -- f'get about it! Of course, actually the French do great with technology -- e.g., J. Neveu in stochastic processes -- but apparently the exploitation of technology is not uniform!

Poaching the scallops until the poaching liquid is 160 F is my guess. So far I've done this for only one trial. Always before I poached the scallops until the poaching liquid was simmering, and essentially always by the time the scallops were served they were overdone, that is, tough and chewy.

On my last trial, I raised the poaching liquid with the scallops, started frozen, to 160 F so slowly that the internal temperature of the scallops may have been 140 F or 150 F, maybe even 155 F. I should take notes on how fast I raise the temperature!

At this point, the scallop cooking looks pretty good.

The main issue is the sauce. With your suggestion, with all the flour, with some comments elsewhere on the Internet, I will try cooking the sauce with the egg yolks to at least a simmer, say, 190 F or 200 F and see what how stable the sauce is. If the resulting sauce is stable, served right away or reheated in the microwave or oven, GREAT.

What would be the right food and wine to go with

R. Strauss's 'Ein Heldenleben'?

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