do flavorful liquids thicken just from reduction or is collegen / starch necessary for thickening?

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             Hi, Nick from Southern California. Just had a culinary II final and my sauce didn't thicken at all after reducing like 3/4. It was a sweet red wine/ fish head reduction and I swear I saw an Italian chef make a syrupy balsamic / sugar reduction that I was kinda shooting for.

             My question is; can you only thicken with bones / starch / gum arabic? or will anything thicken if reduced enough?
 
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Ok. So sugar, which when cooked withg water becomes a thicker syrup can be a thickener. Makes sense. Yeah. I probably needed a bunch more sugar.

                 Thanks for your input Chef EDB
 
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You can reduce water until the cows come home and it will not thicken. Cream however will thicken. So will OJ. Beer will not. Vegetable stock will not. Yada, yada, yada...

I would think that your sauce would thicken with reduction because you mentioned fish heads which contain gelatin and sweet wine which would indicate sugar content: but experience tells me that it would take pretty significant reduction to thicken, more than 3/4 for sure. Almost dry or sec and I would think that it should thicken.
 
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So the starches and sugars in beer and vegeatbles will not thicken but those in oj will.. I need much more practice.                  Thanks for your input.
 
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Carrot juice will thicken, carrot stock will not. Depends upon sugar level. There is not enough in stock.
 
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Carrot juice, nice. what about rice? If you add rice to stock then strain it, will it thicken?
 
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There was a famous French chef (Bernard Loiseau) who thickened all his sauces with his homemade carrot puree rather than using starch or stock.... I have his recipe in one of his books if you need it. Knowing the man, the ingredients are most probably "carrots, water", and everything else is in the technique. 
 
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There was a famous French chef (Bernard Loiseau) who thickened all his sauces with his homemade carrot puree rather than using starch or stock.... I have his recipe in one of his books if you need it. Knowing the man, the ingredients are most probably "carrots, water", and everything else is in the technique. 
Yes FF you are so right, Bernard Loiseau did this with Eggs Meurette and Beef Bourguignon  and maybe alot of other dishes.
 
 
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"So the starches and sugars in beer and vegeatbles will not thicken but those in oj will.. I need much more practice.  "

The starches in wine/beer have been converted to alchohol by yeast, any reduction you do will either NOT thicken, or have to be reduced to a very small amount to "thicken".

There are thickening agents, like flour, potato starch, gelatin from bones, etc, which "thicken" due to their properties.

Recuctions are made simply by reducing water content, leaving behind things which aren't water. (to oversimplify things a little bit), if there is nothing left after evaporation, then there is no "thickening". Tomato sauce, for example... thickens because you evaporate all the water content in the tomatoes.

Sugar syrup thickens, because you're mixing water and sugar... then evaporating the water content, thereby increasing the sugar to water ratio beyond what you started with. (this is why juices get thicker as they reduce)
 
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Joined May 15, 2010
There was a famous French chef (Bernard Loiseau) who thickened all his sauces with his homemade carrot puree rather than using starch or stock.... I have his recipe in one of his books if you need it. Knowing the man, the ingredients are most probably "carrots, water", and everything else is in the technique. 
Would he cook and strain the carrot puree and use the juice? I just wonder because carrots are so fibrous that its hard to imagine adding a cold puree of carrots to thicken a sauce.


"So the starches and sugars in beer and vegeatbles will not thicken but those in oj will.. I need much more practice.  "

The starches in wine/beer have been converted to alchohol by yeast, any reduction you do will either NOT thicken, or have to be reduced to a very small amount to "thicken".

There are thickening agents, like flour, potato starch, gelatin from bones, etc, which "thicken" due to their properties.

Recuctions are made simply by reducing water content, leaving behind things which aren't water. (to oversimplify things a little bit), if there is nothing left after evaporation, then there is no "thickening". Tomato sauce, for example... thickens because you evaporate all the water content in the tomatoes.

Sugar syrup thickens, because you're mixing water and sugar... then evaporating the water content, thereby increasing the sugar to water ratio beyond what you started with. (this is why juices get thicker as they reduce)
Ok, so you could use sweet liquors to make thicker sauces because all of the sugars haven't been converted to alcohol and thus can become syrupey when the liquid is reduced. Very cool. Plus it now seems to me that a 'reduction' and a 'thickened reduction' are not necessarily the same thing. Thanks for the scoop.
 
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Would he cook and strain the carrot puree and use the juice? I just wonder because carrots are so fibrous that its hard to imagine adding a cold puree of carrots to thicken a sauce.

No, he would use the whole puree, no straining. Given the right tools you should be perfectly capable of making a silky smooth carrot puree without any fibrous texture. I'll try to pull out the recipe. 
 
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 I just wonder because carrots are so fibrous that its hard to imagine adding a cold puree of carrots to thicken a sauce.

 
 Purees are thicker than liquids so it is only natural for them to "thicken" a sauce. Say on a scale of 1-10 with 10 being the thickest, a puree is a 10 and your sauce is a 1. Take equal amounts of puree and your sauce and mix and suddenly you have a 5.
 
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ok. i see now. i would have figured that a vegetablke pure would make an undesirably grainy sauce, but i guess you could puree the balls out of it. how about flavor though? could you do a veggetable puree for a steak sauce?
 
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ok. i see now. i would have figured that a vegetablke pure would make an undesirably grainy sauce, but i guess you could puree the balls out of it. how about flavor though? could you do a veggetable puree for a steak sauce?
Yes, that's what Loiseau did. Basically the carrot puree adds a little sweetness, which can sometimes be beneficial to counterbalance acidity. 
 
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Very interesting. I would realy like to know more about how flavor components adjust and effect each other, I think this is a big part of what being a culinary artist is all about. BTW Loiseau... What a bitter end to a chef.
 
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Oh. Question.. So roux thickens with time on heat (to a certain point). Gelatin is slowly taken from bones and thickens as it cools. Gum arabic thickens immediately (but has undesireable flavor for a couple hours).But what about a vegetable pure? Does it loose or gain its thickness when cooked? Similarly, what if you used one of those cooking food processors to make a vegetable thickener, could you over mix-cook it? And does over mixing and long cooking dissapate the flavor of such a thing?
 
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Roux has a thickening power, meaning it will thicken a lot of liquid. A carrot puree like the one Loiseau used is thick, so when mixed with something thinner, it thickens it a little bit... I think the way Cheflayne explained it earlier in this thread is perfect.

Here it is if anyone's interested. It's pretty simple really.

Bernard Loiseau's carrot puree.

Bernard Loiseau liked to use this light puree to sweeten and thicken his sauces. For this, add 1 Tbspn puree to the jus and mix.

1 carrot

Coarse salt

Peel and wash the carrot. Cut it in 1cm slices. Boil 1/2 liter water with 1/2 tsp salt in a small saucepan. Cook the carrot for 25mn. Drain and rinse under cold tap water. Mix and strain through a tamis or sieve to make the puree very smooth.
 
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