Cooking with yoghurt (yogurt)

[Brogan]

I've been cooking Indian food for decades--first learned from Indians temporarily resident in the US, then in a couple of residential kitchens in India. But I absolutely can't cook anything with dahi without it curdling. No matter how slowly I add it, no matter how low the temperature, it curdles. Is it because I'm using low-fat rather than whole-milk? If not, what am I doing wrong?

 

Please, I most humbly beg of you, can someone help me?

[Okanagancook]

I am not sure where I got this but it is in my "kitchen notes" section MacGourmet.  I've not tried it either.  For what it's worth, maybe someone else has experience with this:

 

How to prevent yogurt from curdling when making curries?
Yogurt is a major ingredient in making Indian Curries. The cow-milk yogurt will separate when heated beyond a given point, unless it is stabilized.
In the olden days, yogurt for cooking was made from freshly drawn buffalo whole-milk. It did not curdle with heat. Technically, foods high in proteins and acids (yogurt has lactic acid), become unstable with high heat. Higher the butter fat, proportionately lower is the amount of protein, that is the case with buffalo-milk yogurt.
You may choose to add Cow-milk yogurt at the end of cooking to minimize effects of high heat. The only problem is that spice flavors will not fully permeate the yogurt.
You can stabilize cow-milk yogurt by stirring-in a starch to the yogurt before cooking. For starch, you can use any flour: Besan (Chickpea flour), Atta (whole-grain wheat flour), Maida (All-purpose flour) or Cornstarch. Cornstarch is flavor neutral.
Steps to prevent yogurt from curdling during cooking
Following steps will prevent yogurt from curdling
1. Use whole-milk (high fat) yogurt.
2. Stabilize yogurt by whisking-in starch before cooking. Add one teaspoon of cornstarch, or 1½ teaspoon of other flours (Atta, Maida, or Besan) to one cup of yogurt.
3. Minimize thermal shock to yogurt when adding to curry being cooked. First shut off the heat. Start with yogurt at room temperature and not directly from the refrigerator. At this point, you may add starch to stabilize yogurt. Temper yogurt just like eggs are tempered in making custard. Raise yogurt temperature gradually by mixing hot curry sauce little bit at a time to the yogurt. After the yogurt temperature has risen sufficiently, add it to the curry. Turn on heat to finish making curry.
4. When the yogurt is made, it is not stirred during incubation, so the structure of yogurt is set in a matrix. After adding yogurt for cooking, stirring vigorously will break down the matrix and cause separation. Gently fold-in yogurt by stirring in one direction (either clockwise or anticlockwise), till the yogurt is well blended.
5. Sometimes, it is possible to fix the yogurt after it has separated. Shut-off heat. Make a paste by mixing one teaspoon of cornstarch (or two teaspoons of all-purpose flour) with ½ Tablespoon of cold water. Stir paste into the separated mixture. Gently heat curry to let it thicken and recombine the yogurt. Repeat if necessary.
 
Recipe for Stabilized Yogurt
Cow’s milk yogurt will separate when heated beyond a certain point. Use of stabilized yogurt will minimize separation.
1. Whole-milk plain yogurt: 1 Quart
2. Large egg white, lightly beaten: 1
3. Cornstarch: 1 Tablespoon
4. Salt: 1 teaspoon
Mix all ingredients together in a heavy saucepan. Whisk. Cook over moderate heat, stirring, in one direction until mixture starts to bubble and comes to a boil (approximately 8 minutes). Reduce heat to moderately low, and simmer until thickened, it will take approximately additional 4  minutes.
Stabilized yogurt can be stored in the refrigerator for 2 weeks

[Anna N]

@Okanagancook

 

I was also taught to mix in some cornstarch into the yogourt but on the whole have found that if you use a high fat yogurt and are careful to bring your dish to just under the boiling point you can avoid the issues of  separation or breakage.  

[patrickamory]

Interesting - I've never had this problem with Indian cuisine. However I do always use full-fat yoghurt, and usually a Middle Eastern brand when I can find it... never added at boiling point.

[Brogan]

Looks as though the yoghurt I'm using may be at fault. Experimentation will definitely take place, first with one or two full fat brands, then if that doesn't work, with the stabilization suggestions. I'm new here, so I don't know all the rules, but is it permitted to mention specific brands? If so, I'd really like to know what brands of yoghurt people are using.

[Smithy]

Since nobody else has answered, I'll go first, but it may not be very useful.  My yogurt tends to be of the generic variety: Dannon plain or Old Home plain, or - if I really want to go upscale - Fage or Greek Gods, also plain.  I tend to use yogurt *in* things as opposed to eating it straight, and for my purposes haven't noticed much difference. 

[liuzhou]

I make my own full fat yoghurt and have never had a problem, either.

[JoNorvelleWalker]

I use full fat yoghurt and whisk chickpea flour into it before adding to the curry.

[Smithy]

I've never tried using chickpea flour as a thickener. Does it act similarly to wheat flour?

[haresfur]

 

I've used Besan to keep yogurt from separating and it works. Don't know how it does as a thickener.