On the Flavor of Butter

Several fierce objections to the idea that butter does’t have much flavor on its own. Being a lover of butter, I’m down with that. However I think it can be fairly said that a lot of factors influence the flavor of butter. In some circumstances butter has lots of flavor, in others it doesn’t.

For example, when it’s cold. A cold pat of butter, even the fiercest butter lover will concede, has less flavor than hot, melted butter. It still tastes like butter of course, and that’s due in large part to a specific compound, a ketone called diacetyl. Diacetyl is abundant in fermented foods, and ranks in the top five on my list of All-Time Yummiest Molecules. But diactyl isn’t the only ketone in cold butter. There are many others, but most of them are locked up inside larger organic acid molecules, and that prevents us from tasting them.

Until of course we heat the butter, at which point these acids — which go by the name of alkanoic acids — start breaking into pieces. When they do the result is a variety of methyl ketones and lactones which are responsible for the the rich aromas and flavors we associate with croissants and brown butter sauces. Of course the effects is heightened with actual browning, which brings all sorts of other flavors to the party.

But butter need not be browned to have its flavor enhanced by heat. If you’re wondering why some pastry makers out there prefer to use clarified butter instead of just plain soft butter, this is a big part of the reason. Butter that’s been heated to the boiling point simply has more flavor, because more of its flavor-producing ketones and lactones have been liberated.

8 thoughts on “On the Flavor of Butter”

  1. It’s interesting to see how and where certain flavors are desirable and where they are not. For example, while you are correct that diacetyl is present in fermented products, typically this is an undesirable fermentation product when making beer, wine, or distillate mash. In fact, with certain [few] exceptions, there are active steps to minimize the presence of these byproducts. During the fermentation itself, making sure that the yeast are in an optimum environment tends to reduce the number of ketones and other fusel alcohols. Environmental stress, such as under-/over- pitching the yeast, pitching into under-oxygenated wort / mash, or thermal stress all contribute to the generation of off-flavors. Additionally, many brewers will add a 2 week period towards the end of a fermentation cycle to allow the environment to scavange some of these products, a process known as a ‘diacetyl rest’. In distillate manufacture, since the ketones, conjeners, fusel alcohols, and methyl alcohols all have different vapor pressures, which allows for the distiller to fraction off the desirable elements (the ethyl alcohol and some of the light congeners) from the mash.

    And yet, in most baking products, we find these flavors not only acceptable, but desirable. How often does one find a recipe for a baguette or a ciabatta which endorse a 2-5 day ferment for the sponge or biga? The extended fermentation at a low temperature increases the production of these ketones through environmental stress to provide a more flavorful dough.

    1. Great comment, Chris, and fascinating! But it’s all about context and expectations isn’t it? People wouldn’t want these flavors in their beer or bourbon, but they love them in their bread, cheese and pickles. Terrific observation. Of course a good thing can go too far. Ketones and aldehydes produce a lot of foul flavors and aromas when they’re overabundant…in overused fry oil or rancidifying fat, blechh. Still…I know some bread bakers whose starters can’t get stanky enough for them. No accounting for taste! I’ll think about this tonight over a pint!

      Cheers and thanks,

      – Joe

  2. I always liked the taste of butter and thought it had a subtle flavor I really enjoyed. I have tasted Irish, French and German butter and each had different flavors with variations in flavors within those countries than across the US. I have cooked but never baked with some of those butters but hadn’t noticed the difference in the finished products, maybe because those are not the predominant flavors in what I cooked.

    1. Hey Margaret!

      I think it’s the same reason that large crystal salts taste so good…instead of salting a food evenly, they deliver the saltiness in pockets…so you get the clean food flavors first, then a big pop of salty flavor, then the clean taste again. I think it’s that variability that makes the uneven salt crystal experience so much more pleasant.

      Thanks for the great question!

      – Joe

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