Using thermometers in the kitchen
In food safety, controlling temperature is a priority that can only be applied correctly if the needs of each food group are known.
Temperature is not a subjective value. Its exact knowledge serves to avoid risk ranges in which microorganisms could multiply in a dangerous way or to ensure intense levels of sanitation capable of eliminating them. In order to know it precisely, it will be necessary to have special thermometers for kitchens, common tools in professional kitchens (mandatory for HACCP systems ), but which are not always used in households.
- Using thermometers in the kitchen and Instant-Read Thermometers Product
The intense temperatures that food is subjected to during cooking should be sufficient to kill microorganisms. Often times, it is recommended to cook the tortillas "well set" or to fry the chicken "well done". However, these expressions are very subjective and are based on personal sensory appreciations since, although for some a certain way may be sufficient, it will not be so for others. On the other hand, studies show that the change in color and texture of a food is not a sign of confidence to assess the intensity of heat applied . A hamburger can acquire a characteristic brown color when cooked without reaching safe temperatures.
On the contrary, the desire to cook it completely and reach safe temperatures, even inside, can lead to an excessive application of heat, with the consequent loss of juiciness, tenderness, nutrients, and even, with the risk of developing so significant processing contaminants (harmful chemicals that result from the application of intense heat on food). The temperature at which a food is kept, either hot or cold once cooked, is also of special interest to avoid post-cooked microbial growth. Only the exact knowledge of the temperature of a food through a thermometer will be a reliable element when assessing its safety.
Different thermometers for the same goal
Currently, there is a great variety of thermometers for food and kitchens, depending on the level of technology and precision, which will be chosen according to their use and needs. Digital food thermometers, where the final temperature can be read on a display, are practical, fast and accurate. Due to their quick temperature reading, they are ideal for large pieces, where this parameter must be verified in several places. They have a more or less fine probe, very suitable for thin foods, which is inserted into the product. Some digital thermometers use a sensor with thermal resistance to measure temperature.
Digital thermometers are not designed to remain in food during cooking, so they should be used shortly before the end of the estimated cook time to verify the final temperatures reached. Corded oven thermometers allow you to check food temperatures without opening the oven door. The base unit, provided with a digital display, is connected to a probe by a long electrical cable. The probe is inserted into the food and the cable runs from the oven to the base unit where the reading is recorded.
Fork thermometers are an ingenious tool that combines both functions. It is a kitchen fork in one of whose teeth a temperature sensor is inserted. It appears in numbers on a digital display or by a lighted indicator on the handle, which indicates whether the food has reached a level of raw, medium or well cooked. It is very useful when grilling, as it accurately and quickly measures the internal temperature of the food, even when the food is very thin. They are not designed to remain in food while cooking in the oven or on the grill and should be used to measure the temperature of food towards the end of the cook time.
Circular indicator food thermometers have a double coil spring made of two different metals, which is why they are also known as bimetallic. The spring, which is connected to the temperature gauge, expands in the heat. This type of thermometer measures the temperature at the tip and along the entire probe, up to a length of about 5 centimeters. The resulting temperature is the average of the temperatures measured across the sensitive area. They can measure the degrees in foods of great size (roasts) or of depth (casseroles of cooked or broth). They can be of two kinds: oven proof, designed to stay in the food while it cooks, and instant read.
Temperature indicators
Single-use temperature indicators are very hygienic. Being disposable, they do not require cleaning or maintenance and, in addition, they can determine very quickly if the food has reached a suitable temperature. These indicators are made of special materials that are sensitive to heat, but suitable for food use. When it is inserted into the food and it reaches the right temperature, the device changes color. They are designed for specific ranges and it is important that these indicators are used only with foods indicated by the manufacturer. They cannot be left inserted into food during cooking , so they must be used towards the end of the time calculated for it.
A very curious type of temperature indicator is the ejector, common in the United States for roasting the traditional turkey on Thanksgiving Day. It is one of the oldest, since its use dates back to 1965. These devices are made of a synthetic compound, approved for use with food, inside which there is a stainless steel spring and an organic detonator material. Once the organic material dissolves as a consequence of the high temperature for which it has been predetermined, the stainless steel spring releases the probe and allows it to be ejected outwards. Although quite accurate, it is recommended to measure the temperature in other parts of the food with a special thermometer for these.
Thermometer hygiene
Like other kitchen utensils , food thermometers can be vehicles for cross contamination, so they must be sanitized between use. Most cannot be submerged in water and must be washed by hand with hot soapy water, with particular emphasis on cleaning the tube (part that goes into the food). In either case, the manufacturer's instructions for use and maintenance of the thermometer should be followed. Some types can be calibrated, that is, the thermometer can be adjusted as precisely as possible to the correct size.
There are two methods of calibrating food thermometers. One consists of immersion in ice water to calibrate at 0ºC and the other in boiling water, calibrated at 100ºC. The probe is inserted long enough for it to warm up. For greater precision, distilled water should be used. Many food thermometers have a calibration nut, under the head, that can be adjusted. Others, however, cannot be calibrated.
The right temperature
Most food thermometers give an accurate temperature reading with a margin of error of less than 0.5 ° C. However, the reading will be correct only if it is placed in the appropriate place on the food. In most cases, the food thermometer should be inserted into the thickest part of the food, without touching bone, fat, or cartilage. In a chicken or turkey, it will need to be inserted at the top of the thigh. In a piece of meat, in the center, and in a hamburger or other thin food, the probe should pass through it horizontally, that is, parallel to the surface. In the case of wanting to measure the temperature of a large and irregular piece, it will be necessary to take it in several places.
In addition to knowing the cooking temperatures, thermometers are used in the kitchen to control refrigeration and freezing temperatures . Most of the electrical appliances for this purpose have built-in devices of this type (mandatory in industrial kitchens). If not, a suitable thermometer, in most cases bimetallic spring, should be placed in the refrigerator and freezer to check the temperature of the same. This can be very useful in the event of overloading the appliance or when there are power outages.
Check that the refrigeration temperature is below 5ºC (some refrigerators have a 0ºC compartment for better preservation of fresh food) and that the freezer is less than 18ºC below zero for proper maintenance of frozen food. Outside of these ranges, food will not be stored properly.