The three common souring agent for cooking are sampalok, kamias and santol. I mean fruits so I never included vinegar in list. Green mango is sour too but I have never heard someone using it as pampaasim sa sinigang. I can try it later maybe.
Whenever the sampalok is needed for cooking, a commercial instant cube version is available. I think its Knorr Sinigang sa Sampalok. Kamias is also available in dry form. It can be bought from public markets. She use this often for sinaing na tulingan.
Big brother loves cooking ginataang labong (young banana shoots cooked in coconut milk). He adds santol seeds and peel to give the dish a sour kick. But santol is only available for a limited period, at the start of the rainy season.
Santol peels are edible. Its taste is a sharp kick of extreme sourness that last for few seconds. In my previous experiment, sweetened santol peels, I noticed that taste of boiled peel extract is good. I thinks its sourness will fit for many kind of dish – especially sinigang.
Now, the idea is to make dried santol peels so it will be available whenever we need it. Plus it will add value inexpensive fruit.
I already prepared the peels for drying. I removed the seeds. Scraped inner soft part. Peeled of the outer skin and sliced to desired sizes. The drying schedule is today but it is raining all day long… I placed the slices inside refrigerator. I will continue the experiment on next sunny day.
update as of june 12, 2011
Today is Sunday and a sunny day. Perfect for drying santol peels.
update as of june 17, 2011
The peels was ready after three days of full sun drying. She used it to cooked pinaasiman na uguraming dagat – fish.
It taste great!