nav[aria-label="Primary Navigation"] { padding: 0; & ul { list-style: none; width: 100%; display: flex; flex-direction: row; justify-content: start; align-items: start; gap: 30px; padding: 0; & li { margin: 0; } & ul li { list-style: none; } } }

Celsius v.s. Fahrenheit

dpietranczyk_49940

Could someone please talk a bit about the difference between Celsius and Fahrenheit? I always see people setting their circulators to Celsius. As far as my understanding goes, Fahrenheit is 30% more accurate than Celsius. Also, seeing as how the commonly used system for temperature measurement in this country is Fahrenheit... why Celsius???

Find more posts tagged with

Recipes Q's

Comments

Chris_Young_80640

Well, both Celsius and Fahrenheit measure temperature, which is a physical property of all matter that describes the amount of heat energy contained in something. Still with me? If your eyes are not already glazing over, then read further:

Both ways of measuring temperature are equally accurate; it's a misunderstanding that Fahrenheit is somehow more accurate. I suspect that belief comes from confusion over the size of each step for the two temperature scales. A single degree Celsius is larger than the a single degree Fahrenheit. An analogy is with measurements of length. An inch is a larger unit of measure than a centimeter. The same is true of Fahrenheit versus Celsius. A step size of a single degree Fahrenheit is 44% smaller than a single degree Celsius. Perhaps this is where you are getting the idea that Fahrenheit is 30% more accurate?

But, just like we can divide an inch into fractions of an inch, and centimeters into millimeters, whether we use Celsius or Fahrenheit, any temperature can be measured as accurately as we would like, but you'll need to use fractions of a degree. Which is a long way of saying that you just need to use decimal places.

If someone reading this is being clever, they might say, "ah ha, but my water bath only lets me set the temperature to one decimal place of accuracy, so if I use Fahrenheit I can be 44% more accurate." Okay, here's my argument against that. Even if such a small fraction of a degree mattered in the kitchen—it doesn't—the technology used in even the highest quality water baths cannot measure temperature more accurately than 0.1 to 0.3 °C. This is the limit of Class A platinum RTD sensors (see here for a typical accuracy table: http://www.thermometricscorp.com/acstan.html). I have certainly read marketing literature for water baths claiming better accuracy. I don't believe it for a moment. Making a thermometer more accurate than this is crazy expensive.

Oh, and there is one more reason that you won't win me over to the Fahrenheit is more accurate camp: the digital brains of the water bath is secretly converting your Fahrenheit input to Celsius and doing all of the math in Celsius anyway.

Okay. Rant over.

As to why we bother giving recipes in Celsius along with Fahrenheit? There are people from over 129 countries using ChefSteps. The only countries that still widely use Fahrenheit? The United States of America, Cayman Islands, Belize, and Palau (bonus points to those of you who know where Palau is, I had to look it up).

Chris

dpietranczyk_49940

Thank you so much. I couldn't find that information anywhere. Well, anywhere I looked... And this all did make sense. So thanks again!

michaelnatkin

I think the trick to switching is that you have to establish some reference points for yourself. Because if you grew up with F, you have an instinctive sense that 40 is pretty cold, 98 is body temp, 160 is nice hot food and so on.

So you have to do the same for C, and fortunately its two key reference points are based on water, which is so crucial to cooking, you have a leg up. Here are a few that I find helpful:

0 - freezing point of water

5 - below this is a safe cold refrigerator storage temp

37 - body temp

60 - above this is a safe hot holding temp (see @Chris's answer here for more details, it is actually more complicated than that of course)

63 - softboiled egg

85 - breakdown point for cellulose, a nice temp to cook many vegetables

100 - boiling point water (at sea level)

Of course there are many more that are useful to know, depending on what you like to cook, but once you "bootstrap your brain" it becomes a lot easier to make the switch.

Chris_Young_80640

Happy to help. Look forward to future questions.

Chris

Lachlan_Hunt_17368

If all sous vide equipment supports °C anyway, there's really no sense publishing the temperatures in °F and perpetuating the use of archaic units, nor encouraging the mixing of incompatible unit systems.

One of the problems with the use of dual units is that people just stick to in comfort zones and avoid learning the superior system. Another problem is that discussions here would often result in American readers/contributors talking about things in their own customary units that aren't readily understood by the rest of the world, and international readers would talk in their own systems, making communication harder.

Instead, this site should pick a single system of units exclusively. The SI system: grams, millilitres, centimetres and degrees Celsius should cover all culinary uses. Then encourage its use throughout the site by all contributors (in comments and forum posts). That would teach readers to think and work with that system alone in the kitchen, and not mix multiple systems, which only serves to create confusion and increase the risk of error.

susan_fox_33805

Here in Fairbanks, AK I learned quickly that -40 F is also -40 C.

Patrick_Ancillotti_6135

@lachlanhunt: Only the more expensive ones do... the home reader may use a thermometer and a cooler, or perhaps a pot on the stove, and some of the cheaper ones may not always do both. I'm thinking that the folks from chefsteps want to avoid a religious war

Mason_Perry_34060

F vs C is really just two different languages, it may be hard for a person used to one of the languages to be forced to use a language they are not comfotable with or familiar with, how hard is it to post 3 extra numbers and cover both languages? Also I am assuming there is software that will convert to what ever units you want, why not make everyone happy instead of forcing everyone to conform to one way.

seijoed

As someone that grew up in EU I'm just gonna say that F isn't a different language, it is just random numbers.

Mason_Perry_34060

Im sure 98.6 means something to you..... I went to paramedic school so I speak F for temp and SI for fluid and drug delivery....

Lachlan_Hunt_17368

@Mason Perry, they're not two different languages. They're two incompatible unit systems, one of which needs to be phased out, along with inches, pounds and the rest of that antiquated system of units.

Also, I'm not sure why you think 98.6 would mean anything to a European. The rest of the world uses 37 °C for body temperature.

Mason_Perry_34060

So do you think English should be phased out as well?

seijoed

98.6 means a bit above boiling water in Denver.... (94.697)

Lachlan_Hunt_17368

Systems of units are not like languages. SI and the related units are meant to be a single, coherent system of units of measurement, co-ordinated through international agreement, and common to everyone in all countries and languages.

Nearly every country in the world has adopted the units as their primary legal units, except for the US, which operates in a confused hybrid state with two incompatible systems of units being used side by side. It's a real shame that the US seems to think it's ok to impose a dual system upon everyone else too.

Anyway, I can't stop this site from continuing to publish the US customary units on here if they want to. I just think they should stick exclusively with metric.

Chris_Young_80640

@lachlanhunt as a trained scientist, I quite happily exist in the world of SI units. Indeed, I even prefer to work in SI units. But it would simply be bad business for ChefSteps to ignore the fact that 80% of our user base prefers imperial—or worse, full blow avoirdupois—units.

Our goal is to provide great content and a high quality forum for sharing ideas and asking questions. We put in extra effort to quote temperature as both Celsius and Fahrenheit for convenience. We also have made it easy for weights to be converted from a default of metric to imperial units at the click of a button (click on weight at the top of any recipe to switch). In the future, we hope to support a user-set default units of measurement.

I would prefer to not see a flame war erupt over units and American hegemony. (Now, if you were willing to get behind the Kelvin, or even the Rankine, scale you might get my vote ;-)

susan_fox_33805

@Chris I'm very happy to see you politely steer the discussion out of the flames. The community here is developing as one that respects one another, shares a passion for cooking, and engages in lively discussion without undue deterioration. I appreciate your quick attention to keep it that way. Cheers!

Mason_Perry_34060

@Seijoed I'm at 6480 feet and water boils at a measly 93 ish C that makes the pressure cooker that much more important!

seijoed

Cool! It is more noticeable when baking than it is while cooking I think.

Mason_Perry_34060

Yes baking gets weird, and most of the time the "High Altitude" version of baking is for 3500 feet LOL

Lachlan_Hunt_17368

@Chris, I wasn't flaming, and I hope it didn't come across that way. I just want to have a rational discussion about why a secondary system of measurement should or should not be given any recognition on a site that is dedicated to professional cooking techniques, where precision is often one of the keys to success. The trend in the industry is definitely moving towards working with metric and away from working with old fashioned measurements, albeit somewhat slower than it should due to the US's reluctance to finish the process they started a century ago.

I really appreciate that most of the recipes have actually been clearly designed for using the metric system, but "dumbing down" the content for those who are merely unfamiliar with metric measurements does nothing to help improve familiarity. People naturally want to stick to their comfort zones and have a fear of the unknown, regardless of the advantages that working exclusively with metric would provide. The advantages I can think of are:

Greater precision compared with ounces.
Less ambiguous units, compared with old fashioned cups, spoons, etc. (Thank you for not using these!), and no confusion between ounces for mass and volume.
A temperature scale that actually has a clear relationship to the temperature of water, used so often in cooking.
The ability to work almost entirely with whole numbers. Never using any fractions and rarely any need for decimal places, except where really high precision is needed.
It's easier to scale quantities up or down, as needed for serving more or fewer people, or for filling larger or smaller pan sizes. (e.g. scaling a cake designed for a 20cm tin up to fill a 26cm tin).
Having a density of roughly 1 g/mL for so many ingredients, particularly liquids, makes estimating or calculating necessary quantites much easier in many cases.
The ability to work with others from all over the world in a common system.

It just seems like you actually do want to encourage the use of metric, but a strategy that involves providing unit conversions doesn't do that successfully. People should instead be encouraged to get tools that measure in metric. Switch thermometers to show Celsius, set scales to display grams, get rulers that measure in millimetres, and for the occasions that measuring volume makes sense, measuring jugs that measure in millilitres.

Most, if indeed not all, digital thermometers do support Celsius, and certainly all digital scales support grams. These tools are built and calibrated in grams and Celsius, and any lbs/oz or °F readings are merely conversions from the metric measurements. And if there are any that don't, there are many cheap alternatives that do. So I don't buy the argument that the non-metric units should be supported for old fashioned equipment that doesn't.

And as for Kelvin, yes, I would support that scale, but consumer level equipment simply doesn't support it at all. Celsius, which has the same magnitude, is close enough, and arguably as a scale more suited to cooking.