Caitlyn Sabev

The confusion here is completely natural. HVAC and home energy pros find this story funny because when you say an air conditioner is 4 tons, we know it’s not weight. It’s a number that tells how much heat the air conditioner can remove from the house in an hour. (Let’s ignore the issues of nominal vs. actual capacity and AHRI de-rating.) A 4 ton air conditioner is one that can remove 48,000 BTUs of heat per hour from the house. For most people, though, 4 tons means 8000 pounds. (A BTU is a British Thermal Unit, approximately the amount of heat you get from burning one kitchen match all the way down.)

Most pros also know how such a common term as ‘ton’ turned into a bit of HVAC jargon. Before Willis Carrier invented the modern air conditioner, people used to cool buildings in the summertime with ice harvested from rivers and lakes in the wintertime. A Green Homes America article quotes ice production figures from the 19th century Ice and Refrigeration journal, indicating that the 1890 crop from the Hudson River was about 4 million tons.

OK, so people used to cool and refrigerate with ice. How does that equate to air conditioning capacity in BTUs per hour, you ask? Well, let’s get quantitative and find out.

When ice is below freezing and it absorbs heat, the temperature increases. When ice is at its melting point, 32° F, and it absorbs heat, its temperature doesn’t change. Instead, it melts. If you’ve had a physics or chemistry class, you may recall that the amount of heat needed to melt ice is called the latent heat of fusion. In Imperial units, that number is 143 BTUs per pound.

That’s actually a lot of heat to pump into a pound frozen water. Once the ice is melted into liquid water, it takes only 1 BTU per pound to raise the temperature 1 degree. So if you’ve got a pound of ice at 32° F, you put 143 BTUs into it to melt it completely. Then it takes only 180 more BTUs to raise the temperature of that pound of water from 32° F to 212° F, the boiling point.

Anyway, getting back to our main discussion, if you have a ton of ice, it takes (143 BTU/lb) x (2000 lbs) = 286,000 BTUs to melt it completely. You could do that in one hour or 10 hours or a year, depending on how quickly you pump heat into it. Somewhere along the line, though, someone decided to use 1 day—24 hours—as the standard time reference here. If the ice melts uniformly over the 24 hours, it absorbs heat at the rate of 286,000 / 24 hrs = 11,917 BTU/hr.

Rounding that number up makes it a nice, round 12,000 BTU/hr. In air conditioning jargon, then, a ton of AC capacity is equal to 12,000 BTU/hr. There it is.

If you’re wondering how this term got institutionalized, it was probably the usual way. People in the industry start using it, and then the professional organizations make it official. An architecture website has a quote from 1912 that claims the American Society of Mechanical Engineers standardized it. It sounds likely, but their numbers don’t work out, so I’m gonna go with Honest Abe on this one and remain skeptical.

For the fearless: If you want to read some funny HVAC banter on this topic, check out this thread in the HVAC-Talk forum. And if you figure out what ‘heat of zaporization’ is, let me know!

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The ultimate version of one of Cuba’s most famous dishes, this Ropa Vieja recipe is positively PACKED with flavor!!  A myriad of flavorful ingredients and spices come together to make this dish truly unforgettable.  Make a double batch while you’re at it and you’ll be glad you have the leftovers!

Shredded beef and vegetables that resemble a heap of colorful rags  – that’s Ropa Vieja.  From the Spanish term for “old clothes”, this is one of Cuba’s most popular and beloved dishes.  So popular in fact that it’s one of the country’s designated national dishes.

This dish dates back to the Middle Ages of Spanish Sephardi, a loose adaptation of a dish that remains popular in southern and central Spain.  Traditionally it was a way to stretch the leftovers of stews such as puchero or cocida, both of which are garbanzo-based dishes as is the original Spanish version of Ropa Vieja.  This dish was later taken to Cuba where the Cubans made it their own.

Central in this dish are beef and tomatoes, both naturally umami-rich ingredients.  Added to that are zesty bell peppers, caramelized onions, and to that we’re going to add some additional ingredients and spices that will make your taste buds sing with joy!

Traditionally Ropa Vieja is made with flank steak.  Have a look around the internet at all the ropa vieja recipes and virtually all of them call for flank.  That piqued my curiosity because here’s the thing:  Flank steak is from the bottom hard-working muscle area of the cow (ie, very lean/very little fat) so it not only has less flavor than some other cuts of beef, it’s also notoriously tough.

Because of its low fat content, flank steak is best suited to very quick, high heat cooking, like grilling.  It’s not the best choice for braising or slow cooking because without the fat content and connective tissue it dries out during the cooking process.  For all of these reasons flank steak used to be one of the cheaper cuts of beef.  But in recent years the price has sky-rocketed and in many places is double the cost of chuck.

But flank still continues to be used in nearly all ropa vieja recipes out of tradition because of its shape – the grains of the cut yield long strands of shredded beef resembling the dish’s namesake, torn clothing.

© Paul Cowan | Dreamstime

Flank steak is unique in that respect with those long tough strands.  But I wasn’t willing to sacrifice tenderness, flavor or cost for the sake of having long shreds of beef.  So I went to three different butcher shops and chatted with their butchers.  First I wanted to see their reaction when I told them I was looking for flank steak for a low and slow-cooked dish.  All three raised their eyebrows and asked me why on earth I’d want flank steak for that.  They all shook their heads and said that, hands down, the best choice for slow-cooked shredded beef was chuck.  Better texture, better flavor and at nearly half the price of flank.

Chuck works so well for slow cooking because the long cooking time over low heat breaks down the cartilage, melts the fat and keeps the beef moist while also adding a ton of extra flavor.  It’s by far the most popular beef cut of choice for slow cooking and shredding.

So what about the aesthetics element, those long strands of beef you get from the flank steak?  Chuck has short strands that after slow cooking and shredding typically look less pronounced and are mushier.  The way around that:  Simply ask the butcher to cut you a piece of chuck that is taller than it is wider (the height running with the direction of the grains).  That way you’ll get longer strands along with a deliciously flavorful, tender and moist shredded beef.

Today we’re going to make some ultimate Ropa Vieja with a wonderfully rich depth of flavor!  In the end you’ll have to make your own judgment call, but I’m pretty confident you’re going to love it!

And at the same time we’re going to take a shortcut and braise the meat in the sauce rather than the traditional method of braising it in water, shredding it and then adding it to the sauce.  Doing it the first way releases those flavorful juices from the beef directly into the sauce and saves us a lot of time.  To mimic the extra step of making a separate stock, we’re also going to add whole carrots, celery and bay leaves and then discard them at the end, infusing the sauce with some umami qualities and natural sweetness from the vegetables.

For our ropa vieja recipe we’re also adding an array of other classic Cuban and Spanish ingredients such as olives, pimientos and capers.  In addition to the red bell pepper that’s caramelized with the onions, we’re also going to add roasted red bell pepper in the end for added smokiness, sweetness and flavor.

You may be wondering, “what’s the difference between pimientos and red bell peppers?  Aren’t they the same thing?”

A pimiento, also called pimento or cherry pepper, is a variety of red chili pepper that is sweeter and more aromatic than red bell peppers (though some varieties of pimientos are hot).  They add a nice element of natural sweetness and flavor to this dish.

All of these ingredients combined with delicious spices result in a truly unforgettable Ropa Vieja – it’ll become a staple dish in your home!

Yes, ropa vieja freezes well!  Freeze it in a freezer-safe container or freezer bag for up to 3 months.

Let’s get started!

Pat the beef dry and sprinkle with salt and freshly ground black pepper.

Heat the oil in a Dutch oven over high heat.  Once very hot add the beef and brown generously on all sides.

I’m using my Le Creuset Dutch oven. I also have the Lodge Dutch oven that is a fraction of the price. I love both of them and use both on a regular basis.

Transfer the beef to a plate.  Do not discard the drippings and blackened bits in the pot, they are key to the flavor.

Add the sliced vegetables to the pot and cook over medium heat for 15-20 minutes until caramelized.

Add the garlic and spices and cook for another minute.

Add the white wine and bring it to a rapid boil, deglazing the bottom of the pan (scraping up the browned bits on the bottom of the pan).

Add the broth, crushed tomatoes, tomato paste and bay leaves.  Simmer for 5 minutes.

Return the roast to the pot along with the pieces of carrots and celery.  Bring to a boil, reduce the heat to low, cover and simmer for 3-4 hours or until the beef is fork tender and falls apart easily.

Discard the celery, carrots and bay leaves.

Transfer the beef to a plate and shred it with two forks.

Return the shredded beef to the sauce.

Stir in the olives, roasted red peppers, capers and pimientos.

Simmer uncovered to thicken the sauce for 30 minutes.

Stir in the parsley.  Add salt and pepper to taste.

Your Ropa Vieja is ready to serve.

And its flavor only improves the next day if you can be patient enough to wait!

Serve with steamed or yellow rice and black beans.

Ropa Vieja only tastes better the next day as the flavors have more time to meld, so this is a perfect dish to make in large batches for leftovers!

Enjoy!

Originally published on The Daring Gourmet June 27, 2016

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