Caramelized butter: a trade-secret level secret ingredient
When I cook for my friends, it is not uncommon for those who taste my food for the first time to ask what it is that I put in a recipe that gives it that distinctive flavor. I'm going to give away one of my secrets today. In about a third or more of my beloved recipes, that irreproducible deliciousness comes from my use of caramelized butter.
Caramelized butter is butter which has been cooked to the point where all the water content has boiled away, and the milk solids fry in the milk fat to the point of blackening. The burnt milk solids are then filtered out. It is also known as "browned butter" or "beurre noisette" in French (literally translated as "hazelnut butter"). Some folks call it "ghee", after the Indian term, but the ghee I've purchased in stores isn't the same as this. It appears that ghee is clarified, but not browned. Caramelized butter smells and tastes qualitatively different from both clarified and regular butter, being fragrant and somehow more intensely buttery than regular butter, with a flavor reminiscent of butterscotch. It can be substituted for clarified butter in many cases.
The name comes from the notion that the lactose in the butter caramelizes in the process, resulting in that amazing flavor, but I must admit, this has yet to be confirmed by a food scientist.
What is it good for?
- garlic bread
- pan-toasted bread, such as for grilled cheese sandwiches
- a condiment oil on ramen
- For anything with phyllo dough, caramelized butter can be substituted for clarified butter:
- bistilla (Moroccan phyllo dough crusted chicken or pigeon pies)
- phyllo-crusted apple tarts
Particularly for grilled cheese sandwiches, you don't want burnt milk proteins on the bread, but it sure would be nice to have that optimally caramelized butter flavor.
What is it not good for?
Caramelized butter isn't suitable for any recipes that actually requires the water content or the milk proteins of butter. For example, if you are making your own puff pastry from scratch, the thing that actually makes the pastry puff is the water content of the butter turning to steam. Caramelized butter has no water content; all of the water gets boiled off.
Why not just use plain butter and brown it in the process of cooking?
I've seen a number of recipes that call for the cook to brown butter in a pan and use it straight away, usually for pan-basting various foods in the pan. I don't like this method because the point where the oil is at its best flavor is well past the point where the milk solids are burnt and overcooked. If you halt the browning to prevent the burning of the milk solids, you're missing the peak flavor of the butter, but if you brown it to completion, you end up with burnt bits of milk solids in delicious butter. Avoid this issue altogether by just preparing a container of caramelized butter, and use that instead.
Step 1: Ingredients and Equipment
- unsalted butter
When you caramelize butter, you will lose about 25% of the volume. With this in mind, estimate how many sticks of butter you'll need to fill the container which you'll store your finished product in.
Only use unsalted butter; the salt content of salted butter ends up in the browned bits that get thrown away, so the salt gets wasted. You can add salt afterwards.
- frying pan
- heat resistant spatula
- glass or ceramic coffee filter (plastic ones are at risk of melting at the temperatures we're working with.)
- several filter papers
- ultra fine meshed skimmer
- airtight glass container for storing the butter
- French press coffee maker, instead of the paper filter and coffee filter funnel. The French press method is superior. (The details of this improvement explained at the filtering step.)
I recommend using a white colored ceramic non-stick pan. A white pan will let you see the color of the butter better, so you can gauge the level of browning accurately whereas a dark pan will not. The reason I'm using a wide frying pan rather than narrow sauce pan is that the wide pan leaves the butter shallow, so it is easy to see the color to judge the level of caramelization.
The ultra-fine meshed skimmer is used to skim froth and foam off of broth and stock. (I know this technique something that isn't unique to Asian cuisines, but I never seem to be able to find these foam skimmers anywhere but Asian markets.)
I recommend getting a good melon baller for scooping the butter when it's all cooled down and solidified. (Honestly, who balls melons anyway? These tools are so useful for coring apples and pears and scooping hard ingredients. It's a shame it's named after it's least useful function.) When refrigerated, the solid butter is too hard to scrape with a butter knife, and a regular spoon is usually too dull to cut into the butter well. The sharp edge of the melon baller cuts scoops out of the hard butter easily. I once broke a glass container trying to scoop out a bit of butter with a dull regular spoon; while pressing into the butter with my spoon, the hard butter suddenly broke and my spoon's tip struck the glass container hard enough to fracture it. To avoid this sort of thing, use the melon baller to scoop the butter.
Step 2: Cooking the Butter
Butter consists of three components: milk fat, milk proteins, and water. These are held together in a solidified emulsion, but the emulsion breaks down when the butter melts. After melting, further heating causes these three components to separate into layers according to their differing densities.
The cooking process sends the butter through several stages.
- boiling off water
— during this process you will hear popping and pinging as the water content gets to the point where it is nearly all boiled off. If the popping is too intense or starts to splatter the hot butter, turn the heat down a bit.
- foaming (boiling off water in the milk proteins)
- drying and frying the milk proteins
— with continued heating, the milk protein foam breaks down as all of the remaining water vapor puffing up the foam is driven off. The protein becomes flaky bits that begin to fry in the milk fat, and they sink to the bottom.
- foaming again (caramelizing and browning the milk proteins)
— after all the water is driven off, the temperature rises well over 300˚F. The lactose in the butter begins to caramelize and the proteins start to burn and turn dark brown, resembling coffee grounds. During this process, a second foaming occurs and the butter gives off a very rich fragrance as it darkens.
This whole process takes about 10-15 minutes. The second foaming should be done under medium-low heat to prevent overshooting the process. Stir the butter intermittently during the entire process, using the spatula to break up any patches of milk protein and to mix the butter. If you do not stir, a portion of the butter and the milk proteins will over-brown before the rest of the butter is cooked.
If you want clarified butter instead of caramelized butter, turn off the heat after the first foam subsides, and skim off the dried out milk protein flakes. The butter is clarified at this point. This is, based on my experience, the best way to make clarified butter.
Differing levels of caramelization
After the second foam stops increasing, you have the option of stopping here for a lighter colored caramelized butter, or you can turn the heat down very low and keep stirring to let much of the foam dissolve back into the butter. The butter will continue to darken a bit in this process and have a more intense flavor. However, the foam takes a long time to dissolve back into the butter, and if you heat it long enough to do so, you may end up ruining your butter and giving it a burnt flavor.
Sampling the butter
If you would like to sample the butter at various points of cooking to find your preferred level of caramelization, prepare some cubes of crusty bread for dipping and keep a salt shaker nearby. Without salt, you won't be able to taste the full spectrum of flavor in the butter. Nudge the foam aside and make sure you're sampling the butter, not the foam. And of course, remember that the butter is extremely hot.
Step 3: Skimming, Straining, and Filtering the Butter
Using the spatula to move the foam aside, you can see that the butter has darkened, and that the milk proteins have become burnt, now resembling coffee grounds. Use the skimmer to remove the foam and strain out as much of the burnt protein bits as possible to minimize the amount of solids the filter must contend with.
The heat should be off by this point, but the butter is still extremely hot, and will remain hot for quite a while. However, if you find that it is cooling too quickly, you may need to turn on the burner to a low heat to keep the butter hot and runny; as it cools, it becomes viscous, and filtration becomes extremely slow.
Set up the coffee filter over a tall glass, and ladle in the butter. The filter will almost certainly get clogged before you're done filtering all the butter. You may need to lift the filter paper to install a fresh filter a few times.
Transfer the butter to your storage container, and cover it. Let it cool to room temperature before putting it in the refrigerator to solidify. In liquid form, it will look quite dark, but as it solidifies in the refrigerator, the color will lighten.
How long does it keep?
When refrigerated, caramelized butter will last well over a year. I used up a batch I made a year ago right before I embarked on making this instructable to re-fill my butter container, and the butter didn't taste the least bit rancid. Whether the heating drove out all the oxygen and removing the water and proteins made it inhospitable to bacteria or some other factor, I don't know, but it certainly does not spoil quickly.
If you keep it at room temperature because you want to use it as a spread, I wouldn't recommend keeping more than you would use in a week at room temperature.
Alternative to filtering
If the filtration process is too slow, the alternative is to just put the butter into your container and leave it to cool; the sediment will eventually settle to the bottom over the course of an hour or so. When you then refrigerate the butter, it will solidify. Since you'll be scooping the butter in its solid form, you can just avoid the sediment at the bottom.
UPDATE: New method using a French press coffee pot
I discovered a new method for filtering, but it requires a french press whose press plate goes all the way down to the bottom of the cylinder, and a piece of filter paper big enough to cover the press plate. I cut a square out of a larger Chemex filter paper for this.
Pour the hot butter into the cylinder of the French press coffee pot, and put the filter paper over the top. Then, put the lid on and use the press plate to push that filter paper into the cylinder, making sure that the paper spans the entire way across, leaving no gaps for the butter to escape filtration. Slowly press the filter paper down through the butter. With gravity working with you rather than against you, you can let the sediment settle for a bit before filtration to minimize the amount of sediment that clogs the paper, and then push the filter paper through the butter. The paper then mostly acts as a way to keep the fine sediment from coming back into suspension when you pour the butter into another vessel.
Clogged filter papers cause the filtration to take a really long time. This is a consistent problem with the pour-through filter method. The fact that the French press lets the solids settle to the bottom rather than on the paper really solves this problem quite elegantly.
I usually salt the butter when I use it rather than salting it ahead of time so I can have full control over how salty I want each dish, but if you want to salt ahead of time, use ultra fine powdered salt, and stir it into the butter after it is cooled down and thick so it will remain dispersed and suspended in the butter. However, if you do this, you'll need to use the filtered butter method; stirring unfiltered butter where you let the burnt proteins settle will end up stirring up the sediment as well.
Step 4: Using the Butter
Scoop out the solid butter using a melon baller, and melt it. Then use it as you would use clarified butter or a condiment oil.
Using it in a spreadable form
If you portion out some of the butter, melt it, and keep it in an airtight container at room temperature, it will solidify to a soft, spreadable consistency akin to regular butter. This works great for buttering bread for grilled cheese sandwiches.
Blending the butter with another oil
Caramelized butter will solidify as it cools down; if you need it to remain liquid (or to reduce the intensity of the flavor), for example, so you can spray it or brush it without needing to keep it on a heat source, blend the butter with a neutral tasting oil such as sunflower oil, canola oil, etc. If you blend it with olive oil, use late-harvest oil, which is golden colored and buttery tasting; early harvest olive oil is greenish and a bit spicy, and doesn't complement butter as well.
When the butter is blended with another oil and refrigerated, the butter doesn't harden as much when cold, and remains more spreadable.
Conclusion and additional thoughts
Caramelized butter is a delicious way to enhance butter for cooking, but butter isn't the only fat that can be caramelized. Bacon fat and chicken fat can also be caramelized; the fat tissue contains glycogen, a carbohydrate that is found in animal tissue. The glycogen caramelizes under extended cooking at frying temperatures. (Full disclosure: this is not yet confirmed by chemical analysis.) Just cook the fat until the fatty bits start to foam; you will see the proteins turn brown as it foams, and the resulting cooked fat will have a new depth of flavor and fragrance that you can't get from merely rendered fats. Then, you can use little spoonfuls of this stuff to add a lot of flavor. You tend to see this process when over-cooking bacon. The bacon may end up over-cooked, but the flavor of the rendered fat reaches its peak flavor at this point, just like butter does when the milk proteins become burnt. Enjoy your new secret ingredient!