Reducing tomatoes to add water later?

[Ruso]

Each time I'm cooking Matar Paneer I wonder during the step where 1st you have to reduce the "tomato-onion-spice mixture" to a paste consistency and then add a cup or two of water? What is the reasoning behind it. To me it sounds like an unnecessary step to evaporate the water before adding it back again.
Anybody has an explanation for this order of steps?

 

[Vertigo]

Each time I'm cooking Matar Paneer I wonder during the step where 1st you have to reduce the "tomato-onion-spice mixture" to a paste consistency and then add a cup or two of water? What is the reasoning behind it. To me it sounds like an unnecessary step to evaporate the water before adding it back again.
Anybody has an explanation for this order of steps?

tl;dr: You aren't doing it to change the water content, you do it to improve the flavor of the "tomato-onion-spice mixture" as it converts into a paste.

 

[stringer]

Each time I'm cooking Matar Paneer I wonder during the step where 1st you have to reduce the "tomato-onion-spice mixture" to a paste consistency and then add a cup or two of water? What is the reasoning behind it. To me it sounds like an unnecessary step to evaporate the water before adding it back again.
Anybody has an explanation for this order of steps?

My guess is 2 things
1. By reducing it to dry you concentrate the flavors.
2. The cup of water is the Indian version of deglazing the pan.

Also, you don't have to cook it that way. There are a billion Indians and they all cook stuff a little different.

 

[Ruso]

tl;dr: You aren't doing it to change the water content, you do it to improve the flavor of the "tomato-onion-spice mixture" as it converts into a paste.

I understand the concentrating the flavor, but if I evaporate 250ml of water from onions and tomatoes and then add 250ml of water from the tap back - what is the difference? It's not like we are adding chicken broth/stock or some other flavorful liquid. I am just trying to wrap my head around this particular "technique".

My guess is 2 things
1. By reducing it to dry you concentrate the flavors.
2. The cup of water is the Indian version of deglazing the pan.

Also, you don't have to cook it that way. There are a billion Indians and they all cook stuff a little different.

I do not think deglazing is the end goal. As the idea is to provide a semi-liquid medium for the paneer and matar to be added too. Similar to a porridge.

 

[Vertigo]

I understand the concentrating the flavor, but if I evaporate 250ml of water from onions and tomatoes and then add 250ml of water from the tap back - what is the difference? It's not like we are adding chicken broth/stock or some other flavorful liquid. I am just trying to wrap my head around this particular "technique".

In the process of reducing the tomatoes and onions by 250ml of water, you create *new* flavors. Cooking food changes the way food tastes, this is a *fundamental* science. When you add 250ml water back to that cooked food from the tap, you have your original volume, but with a different (and hopefully improved) flavor.

 

[Ruso]

Evaporating water should not change the flavours per se, just make them more concentrated. Since the temperature of evaporation is more or less constant through out the process. Hence any changes in flavour should have occurred during the first minutes of the process.
The next step, where the “puree” is added to the hot oil might do something, but from my experience the water content is still too high to produce any caramelization or maillard. But being in contact with very hot oil might do something.

There might be some changes in how the dish tastes, but I wonder how much!? Does it worth 30-40extra minutes that it takes to evaporate the water? I dunno, maybe I should try adding stock instead of water to not feel like its a waste of time…

 

[stringer]

I understand the concentrating the flavor, but if I evaporate 250ml of water from onions and tomatoes and then add 250ml of water from the tap back - what is the difference? It's not like we are adding chicken broth/stock or some other flavorful liquid. I am just trying to wrap my head around this particular "technique".



I do not think deglazing is the end goal. As the idea is to provide a semi-liquid medium for the paneer and matar to be added too. Similar to a porridge.

Evaporating water should not change the flavours per se, just make them more concentrated. Since the temperature of evaporation is more or less constant through out the process. Hence any changes in flavour should have occurred during the first minutes of the process.
The next step, where the “puree” is added to the hot oil might do something, but from my experience the water content is still too high to produce any caramelization or maillard. But being in contact with very hot oil might do something.

There might be some changes in how the dish tastes, but I wonder how much!? Does it worth 30-40extra minutes that it takes to evaporate the water? I dunno, maybe I should try adding stock instead of water to not feel like its a waste of time…

It's a very common technique. The Indian guy I worked for said he did it to concentrate the flavors and improve the texture. If the water isn't completely evaporated then you haven't softened the spices and extracted and concentrated the flavors as much as you can.

Adding any kind of animal stock would be a huge no-no if you want to stay authentic. Veggie stock would be fine I guess.

But like I said, it is just one technique. There are many. If you think it's a waste of time and you can get good enough results skipping the step, then don't do it. Recipes and techniques aren't sacred.

If you think about it, the French do the same thing when they bring a sauce to "au sec" and then add more liquid.

 

[Jovidah]

Just a guess but maybe it's because the longer cooktime reduces acidity?

 

[Vertigo]

Evaporating water should not change the flavours per se, just make them more concentrated. Since the temperature of evaporation is more or less constant through out the process. Hence any changes in flavour should have occurred during the first minutes of the process.
The next step, where the “puree” is added to the hot oil might do something, but from my experience the water content is still too high to produce any caramelization or maillard. But being in contact with very hot oil might do something.

There might be some changes in how the dish tastes, but I wonder how much!? Does it worth 30-40extra minutes that it takes to evaporate the water? I dunno, maybe I should try adding stock instead of water to not feel like its a waste of time…

Dude are you actually trolling me rn?

Okay so for like the third time now: you are not just evaporating water when you initially cook the tomatoes and onions. You are *cooking* the tomatoes and onions. You are reducing acidity, converting starches to sugar, making sweet what once was tart. A piece of sliced onion is this awful thing that can make you cry, but you run it under cold water and suddenly you don't want to cry anymore and it tastes better on a sammich. Imagine how that same onion changes when you apply fire and time?

Am I on drugs, seriously? Like are you for real?

 

[M1k3]

Evaporating water should not change the flavours per se, just make them more concentrated. Since the temperature of evaporation is more or less constant through out the process. Hence any changes in flavour should have occurred during the first minutes of the process.
The next step, where the “puree” is added to the hot oil might do something, but from my experience the water content is still too high to produce any caramelization or maillard. But being in contact with very hot oil might do something.

There might be some changes in how the dish tastes, but I wonder how much!? Does it worth 30-40extra minutes that it takes to evaporate the water? I dunno, maybe I should try adding stock instead of water to not feel like its a waste of time…

Make Marinara without cooking it.

Then make Marinara with cooking it.

Compare the flavors.

 

[bsfsu]

Reduce to intensify flavours and add water at a later stage to "loosen" the mixture to a sauce consistency.

Adding water at different stages of cooking is a common technique in foods from all around the world.

You can speed up the cooking process but you won't get the "flavour".

 

[Michi]

Evaporating water should not change the flavours per se, just make them more concentrated. Since the temperature of evaporation is more or less constant through out the process. Hence any changes in flavour should have occurred during the first minutes of the process.
The next step, where the “puree” is added to the hot oil might do something, but from my experience the water content is still too high to produce any caramelization or maillard. But being in contact with very hot oil might do something.

There might be some changes in how the dish tastes, but I wonder how much!? Does it worth 30-40extra minutes that it takes to evaporate the water? I dunno, maybe I should try adding stock instead of water to not feel like its a waste of time…

There are lots of dishes where the time something is cooked for markedly changes the flavour. It takes time for the water to evaporate, so the extra step does add that.

I hear you on the 100 ºC upper temperature limit argument. In theory, whether all the water is added at the beginning and then reduced, or added back again after reducing the mixture should make little difference. But, towards the end of reducing, when almost all the liquid is gone, the parts of the mixture that are in contact with the pan will get hotter than 100 ºC. And that will change flavour. Sugars that were released earlier will start to caramelise, proteins will denature more, oils will evaporate at a different rate, etc.

Overall, the difference in flavour will probably be subtle, but the two techniques will definitely produce different results.

 

[mengwong]

But, towards the end of reducing, when almost all the liquid is gone, the parts of the mixture that are in contact with the pan will get hotter than 100 ºC. And that will change flavour. Sugars that were released earlier will start to caramelise, proteins will denature more, oils will evaporate at a different rate, etc.

I’m fond of this explanation

Overall, the difference in flavour will probably be subtle, but the two techniques will definitely produce different results.

A sous vide experiment should be illuminating: seal in bag, cook at 90°C.

Without sous vide, cook in pot below boiling point. Remove samples at 0,1,5,10 mins after reaching 90°C; rehydrate to same wetness. Taste.

 

[aporigine]

Dude are you actually trolling me rn?

Okay so for like the third time now: you are not just evaporating water when you initially cook the tomatoes and onions. You are *cooking* the tomatoes and onions. You are reducing acidity, converting starches to sugar, making sweet what once was tart. A piece of sliced onion is this awful thing that can make you cry, but you run it under cold water and suddenly you don't want to cry anymore and it tastes better on a sammich. Imagine how that same onion changes when you apply fire and time?

Am I on drugs, seriously? Like are you for real?

This. Caramelization and a whole host of hydrolytic and rearrangement reactions occur, especially in the “boundary syrup” that is hotter than boiling.

The sous vide experiment described above is a great exercise to note flavor changes brought on by each method.

 

[mengwong]

It's a very common technique.

the French do the same thing

a common technique in foods from all around the world

Kulet
Nearly every stewed dish (also called ‘Wot’) in the Ethiopian repertoire calls for kulet – often lots of it. Kulet consists mainly of three ingredients: finely chopped red onion, grated garlic and ginger. While the quantities of each ingredient can vary depending on the recipe, in kulet you are required to cook the chopped onion first, without any oil, until soft and almost dry. Only then do we add the garlic and ginger along with the oil until the mix caramelises and becomes kulet. During the non-fasting season a spoon of niter kebbeh is also added in the making and scenting of kulet. Its sweetness through slow-cooking and the caramelisation process balances the spices, giving texture and body to sauces that use it as a base. Be patient when chopping as the sauce should be quite smooth rather than chunky. Shallots are prized for their flavour and were the most dominant ingredient in markets during my childhood, but today cooks generally use red onions, which are less laborious to peel and chop. For smaller quantities of kulet, the recipes in this book use oil to avoid burning the onion mix.

from Ethiopia: Recipes and Traditions from the Horn of Africa, by Yohanis Gebreyesus
https://a.co/0RwqF5d

 

[Ruso]

Make Marinara without cooking it.

Then make Marinara with cooking it.

Compare the flavors.

1. The better test is to cook marinara.
2. Take a half of it and reduce by a cup, then add a cup of water back and bring to boil.
3. Compare to another half.

Which is actually is a great idea. I should do it next time I cook marinara, as it happens more often than I cook matar paneer.

There are lots of dishes where the time something is cooked for markedly changes the flavour. It takes time for the water to evaporate, so the extra step does add that.

I hear you on the 100 ºC upper temperature limit argument. In theory, whether all the water is added at the beginning and then reduced, or added back again after reducing the mixture should make little difference. But, towards the end of reducing, when almost all the liquid is gone, the parts of the mixture that are in contact with the pan will get hotter than 100 ºC. And that will change flavour. Sugars that were released earlier will start to caramelise, proteins will denature more, oils will evaporate at a different rate, etc.

Overall, the difference in flavour will probably be subtle, but the two techniques will definitely produce different results.

Thanks for a balanced response.

Kulet
Nearly every stewed dish (also called ‘Wot’) in the Ethiopian repertoire calls for kulet – often lots of it. Kulet consists mainly of three ingredients: finely chopped red onion, grated garlic and ginger. While the quantities of each ingredient can vary depending on the recipe, in kulet you are required to cook the chopped onion first, without any oil, until soft and almost dry. Only then do we add the garlic and ginger along with the oil until the mix caramelises and becomes kulet. During the non-fasting season a spoon of niter kebbeh is also added in the making and scenting of kulet. Its sweetness through slow-cooking and the caramelisation process balances the spices, giving texture and body to sauces that use it as a base. Be patient when chopping as the sauce should be quite smooth rather than chunky. Shallots are prized for their flavour and were the most dominant ingredient in markets during my childhood, but today cooks generally use red onions, which are less laborious to peel and chop. For smaller quantities of kulet, the recipes in this book use oil to avoid burning the onion mix.

from Ethiopia: Recipes and Traditions from the Horn of Africa, by Yohanis Gebreyesus
https://a.co/0RwqF5d

Kulet, as written, is similar to a sofrito or zazharka, etc. Which is not the same as reducing tomatoes and then adding the water back to the mixture.

 

[Heckel7302]

I’m fond of this explanation

Whether intentional or not, great pun right there.

 

[benomatic42]

Re the indian style, I learned from Indian friends as "cook the tomato mix until the oil leaks back out". I always assumed the same as this:

But, towards the end of reducing, when almost all the liquid is gone, the parts of the mixture that are in contact with the pan will get hotter than 100 ºC. And that will change flavour.

and further guess that the oil running out is a visible indication that most/enough of the water is out for much of the tomatoes to cook > 100ºc. And AFAICT it definitely tastes better this way. I haven't done side by side, but I now do this with nearly all tomato sauces.

 

[Jovidah]

I've seen 'cook it until it starts to split' in some bolognese recipes as well. Which definitly tastes different after a long simmer...

 

[Heckel7302]

I've seen 'cook it until it starts to split' in some bolognese recipes as well. Which definitly tastes different after a long simmer...

For the bolognese I make there are two wet to dry stages

Brown meat then remove
Sweat aromatics
Tomato paste until cooked out
Add wine and simmer until almost dry
Add whole peeled tomatoes and cook until almost dry
add back meat along with stock and milk
Simmer a few hours

Finished product certainly would suffer without cooking out all that water in the middle

 

[Jovidah]

Alcohols are a bit of a special case. Apparently if you dillute them more by adding the water before reducing it you'll retain more of the alcohol.

 

[Johnsmyname]

Depending on the other ingredients, the volatility of the compounds comes into play too. Just because they are in a liquid doesn't mean that compounds themselves are not evaporating. This is just a small component to add to what others have said. Lots of things happening besides water floating away and then being added back.

Next time you make tomato sauce, cook all the canned tomato products for 1-3 hours or whatever you like, then during the last 10-15 minutes add some fresh tomato back in. You will get both the rich complex cooked tomato layered with fresh more tomatoey tomato. It will be a tomato extravaganza! Just make sure you add back a few tablespoons of fresh water though or it won't work at all

 

[nopomo]

I like the results from a pressure cooker—minimal reduction, but everything’s heated beyond boiling.