I’ve noticed a lot of people see a kettle sour on a menu and say, “kettle sour,” like it’s a statement that combines trepidation, fear, and the unknown. “Kettle sour” serves as the enigmatic phrase echoed several times through a heady indie film.
“Kettle sour.” You can practically hear Orson Welles uttering the words on his deathbed after he finishes trashing his bedroom.
Contrary to the mystery surrounding the term, kettle sours are anything but a mystery; in reality, they serve almost as an entry-level sour while providing brewers with a quick and dirty way of adding another unique beer to their menu.
Sit back, dear reader, and learn more than you ever wanted to know about kettle sours.
What is a Kettle Sour?
What is a kettle sour? Well, it’s a sour beer, but not like those infinitely tart beers that your one friend insists you drink and, yes, even enjoy.
Kettle sours get their name from the stainless steel mash tun, or steel “kettle,” that they’re brewed in. Aside from that, the beer isn’t wholly unique and follows century-old methods of beer making.
Back in the good ole days, all beers were sour. Because nobody knew what bacteria were, brewers didn’t know that the little fellas wildly changed the flavor of the beer. Once that was deduced, brewers ripped bacteria out and could craft beers that lacked a sour tinge.
A kettle sour uses these bacteria (typically lactobacillus) to alter the flavor of the beer, adding a sour edge. Unlike other methods like spontaneous fermentation, the process of adding the lactobacillus to the sour is measured.
The result? A straightforward, fairly one-dimensional sour that should be more approachable than its counterparts.
Sour vs Kettle Sour
Not convinced that you might actually enjoy a kettle sour? Ok, let me compare it to the sour beer.
Traditionally, sour beers age in barrels, often over the span of months or even years. Kettle sours age in their steel kettle over a matter of days and weeks. This drastically shortens the brewing time but also gives the kettle sour less time to take on complex and unique flavors.
Also, because kettle sours take less time to brew, they tend to be more one-dimensional — but this ain’t a bad thing. A good kettle sour will nail a clean, slightly sour flavor without making you reach for your Tums.
Traditional sours have quite a bit more variety and draw their sourness from different places and bacteria (and sometimes both). There are also various types of sours, including the kettle sour. Yup, we’ve got ourselves a squares and rectangles situation.
But, as I point out in the article linked above and earlier in this article, all beers were once a little bit sour. If you’re dragging your feet approaching the sour style of beer, a kettle sour could be an excellent jumping-off point.
What does a Kettle Sour Taste Like?
Kettle sours typically use lactobacillus, or lacto, as the main bacteria to bring some sour to the beer. In my experience, lacto adds a genuinely milky flavor to a lot of beers (see Milkshake IPAs).
Thank god that kettle sours rarely have the same milky taste. Can you imagine a sour milky flavor? You can make that in your own home with a carton of milk and four weeks’ time.
Aside from lacto, brewers have some room to get creative with kettle sours. Some can limit the amount of oxygen in the lactobacillus aerobic process (making it anaerobic) to alter the flavor. Others experiment with different hop varieties to change the flavor, consistency, and color of the brew.
Another way to add some tasty flavor is by tossing fruit into the mix. The flavor often comes out subtle yet well blended.
There must be some brewery out there that proves me wrong, but I would say as a blanket statement that kettle sours tend to be:
- Less sour than other sours
- A lower ABV than other sours
- Nice to drink on sunny days
Perhaps the biggest downside of kettle sours is that they aren’t very common. Is this due to the masses not wanting to approach something that sounds like a mix of kettle corn and acid? Maybe.
If you managed to make it this far, let me impart this bit of wisdom to you: try a kettle sour, even if just once, because who knows when you’ll see one on a menu again.