By Kollengode S Venkataraman

My long craving for the authentic home-made dahi (tayir in Tamil and Malayalam, mosaru in Kannada, and perugu in Telugu), recently got satisfied in a totally unexpected way.   Let me preface that this uniquely Indian and perfected home-made product — unique in its texture and taste — goes by the generic name yoghurt in the US.  As Dahi aficionados know only too well, this is only an approximation.

Many of our everyday eats are products of biochemical reactions. Breads — both the freshly baked “artisan” type and the run-of-the-mill types in grocery stores — are “leavened” due to fermentation of bacteria in yeast. Bakeries take great care in preserving the culture of the original strains of bacteria in their starter dough for tens of years so that the breads come out the same way year after year. What makes the French sourdough bread and the Italian bread unique, are the differences in the yeast-enriched starter dough, the flours used, and in the baking techniques. Wines, beers and antibiotics too are products of biochemistry.

The perfect dosas and idlis require that the batter you make by wet-grinding blends of well-soaked urad dal and boiled rice — please do not mistake boiled rice for cooked rice — is allowed to ferment for several hours. The batter acquires a sour taste and is full of gas bubbles (products of fermentation) which make the idlis soft; while making dosas, the batter spreads better on the skillet and the dosas come out with countless small holes when the tiny gas bubbles burst as if by magic design. Indian achars and the Korean kimchi are products of unaerobic fermentation. The Japanese natto, a breakfast item in parts of Japan, is fermented soya beans.

Back to good old authentic tayir that goes by the generic name yoghurt in the US. The desi dahi is very distinct — it has its own texture and taste — and is very different from its distant cousins, zabadi (Arabic), the giaoúrti (Greek) and yoghurt (Turkish). The best dahi I had outside my home is the Brijvasi-type in Delhi. Obviously, the best dahi you know is what your mom made in India.

After arriving in the US, I reconciled myself to the standardized salt-laden buttermilk in cartons and the plain Dannon yoghurt from grocery stores. The fine print on the Dannon container said it contains live acidophilus bacteria. So, I tried to make tayir with 4% milk using Dannon yoghurt as the starter. For those who know nothing about making tayir at home, all that you need to do is:

1. Bring ~½ gallon of milk to boil and cool it to room temperature;
2. Add approx. two or three tbsp of starter yoghurt to the milk, while gently stirring the milk with a spoon; and
3. Let the blend stand overnight at temperatures ~75 F.

When I did this, however, what I got was not the tayir I was used to, but a gooey yoghurt that scooped like a thickened milkshake; worse still, it tasted terrible compared to the tayir I know.  I wanted the tayir to handle well — I should be able to cut it into slices like pudding. I also wanted my tayir mellow, and naturally and very mildly sweet (without added sugar) and mildly tart and sour all at the same time, like the tayir my amma made. What I got was not anywhere close.

Having known enough about the effects of time, temperatures and concentration — a subject called chemical reaction kinetics — in my Chem. E. education, I tried all combinations of setting time, temperature and the quality of milk, (different blends of 2% and 4% milk). I ended up with the same gooey stuff, sometime even worse. I gave up, attributing my failure to the type of milk here. This was nearly 15 years ago.

Then recently I was talking to Janaki Raghupathi of Murrysville, shooting the breeze. I’ve known her for over 25 years. I casually told her about my reasoning on why we cannot make good tayir here.

She laughed. “Venkataraman, it has nothing to do with the milk, but everything to do with the starter tayir,” she was categorical. She continued, “Over 30 years ago, I brought with me a small bottle of tayir from my home in India. I used it as a starter material for making tayir at home. I got good tayir from the regular 2% or 4% milk. Every time I make a new batch, I set aside a small portion for the next batch. Why don’t you try with the starter tayir from me.”

I made the tayir at home using her starter stuff using a blend of 4% and 2% milk. I boiled ½ gallon of the milk and cooled it to room temperature; then added 3 tbsp of Janaki’s starter tayir, gently mixing it into the milk by stirring with a ladle. I kept the mixed blend overnight in the oven chamber of our cooking range with the heat turned OFF. However, the 40-w light in the oven chamber was turned ON to keep the temperature around 75F. This is important during winter.

Next morning, when I stuck a teaspoon into the fermented product, I sliced into it much like the tayir I grew up with in Kerala. I knew right then that this was different. I was excited. With great expectation, I put the spoonful of the tayir into my mouth.  Ahh! I was in heaven! I got the same taste of the desi dahi, very mildly sweet, at the same time mildly sour and tart as well — very close to the tayir my mom made decades ago.

So, if you want to make the dahi, tayir, or mosaru, or perugu that you grew up with in India, get some authentic starter material from friends.  Follow their instructions to get it right and enjoy it with your family.

When you do this and get the authentic product, I have only one request. Call it by its authentic name, Dahi, Tayir, Perugu, or Mosaru.  And never ever call it yoghurt or curd. Because it simply is not, and can never be — the same way French sourdough bread is not the same as the Italian bread.     ♣

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