Onion paste

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Suthseaxa

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I have a few recipes which include instructions to blend onion to a paste to be used in sauces. Sometimes, when I do this, the resultant sauce is rather bitter. Sometimes it is not. Obviously the uncertainty is not great. Any tis of removing any potential bitterness or avoiding it in the first place? Perhaps soaking in water/salt?

There is one recipe where ginger, garlic, onion and cashews and blended into a paste and that tends to come out fine. I have another one I want to try and do where an onion paste is used as a marinade and then added to another sauce and boiled. I'm concerned this will come out badly!
 
Suthseaxa, I've read recipes that use raw onions in salads, that it will soften the taste, if you soak them in ice water/cold water. I believe it removes the often sulfuric flavor/hot flavor that is created when cutting into the cellular walls of an onion. I don't know if this is the flavor of bitterness you are describing.

On cooked onions, they will sweeten if sauteed in butter or oil, as they first become translucent, then slightly browning/caramelizing as they lightly brown.

My DH is very sensitive to the taste of raw onion, so I tend to cook them quite long before any other cooking, so that he likes them. I don't know if I answered your question, as I'm not sure what would cause bitterness.
 
I've made several Indian Recipes that called for an Onion paste.
I had to fry up the onions first in a little oil until translucent. Then let them cool down before blending them into a paste.
The result is a slight sweet, mild oniony flavor.

Making fresh onions in a paste would definitely be much stronger and possibly have that bitterness you are referring too.

If diced, then soaked in cold water for a bit, drained , rinsed again... That would definitely reduce the potency of the onion, and may make for a less bitter onion paste ( Not 100% sure though, I've only made paste out of the cooked onions)
 
Interesting, never heard of using cold water. Soaking or even better leaving onion under running very hot water for sure removes bitterness of the onion. That's true and tasted. Also soaking in the vinegar helps remove the bitterness, but then you kind of have to slice or dice the whole thing, unfortunately even after rinsing the some of the vinegary taste remains.
Of course you can try using sweet onions, but then they cost more.
 
Interesting, never heard of using cold water. Soaking or even better leaving onion under running very hot water for sure removes bitterness of the onion. That's true and tasted. Also soaking in the vinegar helps remove the bitterness, but then you kind of have to slice or dice the whole thing, unfortunately even after rinsing the some of the vinegary taste remains.
Of course you can try using sweet onions, but then they cost more.

Rick Bayless and other chefs recommend soaking in cold water. Vinegar or citrus juice works, too. I only use one of those if it's part of the recipe, like for salsa.
 
Thanks for the tips everyone. It's definitely a sulphurous flavour. Quite sharp and tangy which does eventually get cooked out if you fry the pate long enough but often requires a lot longer than I'd like.

The only concern I have is that frying the onions first before turning into a paste might cook out some of the acids or enzymes required for marinating. Unless of course it's just for flavour. I'll have to experiment and let you know how it tastes!
 
Okay if the bitterness is the sulphurous flavor, then garlic, onions, shallots, and leeks would deserve the same treatment. All of them are in the allium family and as you cut the cellular walls, sulfur does affect the taste. In garlic it is allicin, another acid. Acids in general will help with softening meat/poultry. I've found that long cooking, does soften the blow from the acids. Anything cooked long enough will lessen the strong bitterness you have talked about.
 
Thanks for the tips everyone. It's definitely a sulphurous flavour. Quite sharp and tangy which does eventually get cooked out if you fry the pate long enough but often requires a lot longer than I'd like.

The only concern I have is that frying the onions first before turning into a paste might cook out some of the acids or enzymes required for marinating. Unless of course it's just for flavour. I'll have to experiment and let you know how it tastes!

What are the rest of the ingredients in the marinade? If there's yogurt, citrus juice, vinegar or wine, that will probably provide plenty of acidity to the marinade.
 
Another vote for slicing and soaking in cold water for a bit.

I occasionally make a recipe for Portugese garlic shrimp where the shrimp are marinated in a paste of onions, garlic, evoo, and salt, then cooked in a little more evoo without wiping off the marinade paste. Even though they're called garlic shrimp, it's the onions that really make it work.

I've found that the onions are often too nasty and overtake the flavor of the shrimp, but a quick soak in water makes them just right.
 
Another vote for slicing and soaking in cold water for a bit.

I occasionally make a recipe for Portugese garlic shrimp where the shrimp are marinated in a paste of onions, garlic, evoo, and salt, then cooked in a little more evoo without wiping off the marinade paste. Even though they're called garlic shrimp, it's the onions that really make it work.

I've found that the onions are often too nasty and overtake the flavor of the shrimp, but a quick soak in water makes them just right.

That's the sort of recipe I'm looking to do. It's actually also fish, the one I have in mind, so that should work well. I'll try it :)
 
So the result of the experiment: not so good.

I soaked the onions in cold water, then rinsed and soaked in salt water for good measure. I blended them and, lo and behold, the sauce had that horrible tanginess, right at the back of the tongue.

However, I am starting to suspect that I may be wrong in blaming the humble onion. There is another recipe which I love to make which also uses a paste of onions, almonds, cashews and coconut. I've not had this problem with this dish.

I did add, to the bitter dish this evening, ginger and garlic, too. I have had this problem with another dish that uses onion-ginger-garlic paste. I wonder if it one of the other ingredients? Perhaps the volume of the onion is preventing the raw flavours from frying off of the ginger/garlic? Perhaps it is just the onion. I have read a post on another forum where someone states "English onions are wholly unsuited to blending into a paste raw"....
 
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