# Can the duration of the whistle determine if food inside a pressure cooker is cooked

Building upon this question, I was wondering if the duration of the whistle can be used to determine if the food inside a pressure cooker is cooked.

As suggested by a couple of answers in the question referenced above, certain things do not work:

• The manufacture recommended two whistles in India, but in Germany it takes 6-7.
• The aroma can not always help, for example in case of making plain rice.

I have been trying to observe this event for the past few days. As the time increases, the duration of the whistle decreases (I have not measured it per se...just an observation). Has anyone else observed this. If this observation is actually correct , can this be scientifically explained?

• When the pressure is reached as indicated by the indicator, you start the time measurement. Very simple procedure. – Optionparty Feb 9 '15 at 13:59
• Usually, the whistle represents that the temperature is too high and the emergency pressure release has been activated. A normal pressure cooker produces very little sound during operation. – Mr. Mascaro Feb 9 '15 at 14:54
• @jbarker2160 That's not true of all pressure cookers. The jiggler type make a fair bit of sound constantly. You're thinking of the spring type, which let out a small amount of steam (if anything) while at proper pressure. There is (at least according to Google) a third type which let out a burst of steam regularly, which is I think the type OP is talking about. – derobert Feb 9 '15 at 17:13

## 3 Answers

The short answer to that question is no. The whistling sound is just a signal to reduce the heat.

Here's an excerpt from the Hawkins Pressure Cooker Operating Guide:

After the pressure regulator is placed on the steam vent, there is at first a very low hissing sound of steam from the pressure regulator. Then steam emission increases to full force and the pressure regulator lifts with a whistling sound. The cooker is now at full operating pressure. This is the point at which to reduce heat and start timing the recipe.

So, the timing or frequency of whistles is a function of how hot the pressure cooker is at any given time, and most importantly, a warning to turn down your stove, so that a catastrophe does not ensue.

As the Hawkins manual explains, start timing your recipe once the cooker has reached operating pressure. The actual timing of course, will vary, depending on the particular food you're cooking.

I have the same problem, as Indian recipes often specify the number of whistles - like 7 or 12. Based on one recipe, I have found that what was said to be 7 whistles took me 80 minutes of slow cooking - an even steady boil. That makes one whistle about 11.5 minutes of standard slow boiling.

• Slow cooking as "in a non-pressurized pot on the stove"? – Stephie Dec 14 '15 at 15:42
• Yes, as in a slow boil on any source of heat, but since yesterday I had a chat with an Indian lady - works at my local Indian Supermarket - and actually the Whistle Standard is not linear. Because the first whistle takes longer, and is not counted, and subsequent whistle intervals depend on the amount of heat. Basically its a very poor timer, and modern Indian cooks are being advised to move off of it. By the by, some comments here do not know that India has its own type of "pressure cooker" and there are all told, three types around the world. – Geoff Dec 16 '15 at 6:27

As far as the indian style pressure cooker, with a seperate weight, the 'number of whistles' typically isn't a standard. It depends on the size, specific weight of the weight, and what you're cooking. Typically, the number of whistles for a specific recipe tends to depend on the specific cooker and you'd quite often hear "4 whistles if its the little cooker, 3 if its the large one"

You'd really want to get familiar with your cooker and experiment a bit, rather than 'assuming' that they all have the same cook-time and pressure.