9:59:59.000,9:59:59.000 - Sinigang—it's sour,[br]it's so comforting, 9:59:59.000,9:59:59.000 and apparently, [br]it's one of the best soups 9:59:59.000,9:59:59.000 in the world [br]according to TasteAtlas. 9:59:59.000,9:59:59.000 So what makes it so special[br]and why do Filipinos 9:59:59.000,9:59:59.000 have so many different ways [br]of making it? 9:59:59.000,9:59:59.000 That's where the main asim kilig [br]kind of thing comes out. 9:59:59.000,9:59:59.000 We're here to interrogate, [br]investigate, and most importantly 9:59:59.000,9:59:59.000 taste our way through [br]the mysteries of Filipino food. 9:59:59.000,9:59:59.000 This is Patikim. 9:59:59.000,9:59:59.000 So what makes sinigang distinct? 9:59:59.000,9:59:59.000 Well, the secret lies [br]in our very Filipino way 9:59:59.000,9:59:59.000 of adding sourness [br]to everything. 9:59:59.000,9:59:59.000 And depending on where you live, [br]those ingredients 9:59:59.000,9:59:59.000 can vary greatly. 9:59:59.000,9:59:59.000 Sinigang is a verb, [br]and versions will vary 9:59:59.000,9:59:59.000 throughout the archipelago. 9:59:59.000,9:59:59.000 We often associate sour [br]with acid— 9:59:59.000,9:59:59.000 sampaloc, batwan, [br]calamansi, etc. 9:59:59.000,9:59:59.000 And most souring agents have citric acid. But I'm wondering if the level of acidity in our sinigang is what affects its sourness. What do you think, Professor Arrow? Thanks, Erwan. So the total titratable acidity is one of the basic and simple tests for us to determine the amount of acid. So when we say amount, that's the concentration of acid present in our sample. So when it comes to food, there are different types of acids present. And normally we report the total titratable acidity on the type of acid. So right now we will test four samples, three of which are fruits. We have the calamansi, the biasong, dibatuan, and then this will be compared to our instant sinigang mixed. There are different types of acid in food. Each fruit will have a distinct type of acid. They may not be the same for all of the samples that we have tested. So that is one factor in terms of the total titratable acidity and in terms of the perceived sourness. So of course, the acids present in the food will greatly contribute to the sour taste of a particular dish. But it is not normally the amount of acid present in the food which dictates the sourness.