Cask ales are a big new thing in the American craft beer scene, and a very, very old thing in the beer world in general. The tannins from the oak used to make the barrels add a layer of complexity to the beer, and can change the flavor in some very pleasant ways.
You’re going to notice more difference between casked and uncasked beers if they’re less hoppy. Malt flavors are more affected by the oak tannins; hop flavors are almost completely unaffected.
The good news is that you don’t actually need an expensive cask, which is difficult to clean and care for. In terms of flavor, there is no meaningful difference between adding beer to oak, or adding oak to beer. You can use oak cubes or chips instead. In fact, homemade wine kits always come with oak chips that you add to the wine to simulate the flavors of the barrel.
There are two factors that determine how much oak flavor you will get–the surface area of the oak, and the time it is in contact with your beer. Oak can be overdone, giving you an unpleasant and astringent beer, so you need a plan of action before you begin. Typically, 1 ounce of oak chips left in contact with the beer 1-2 weeks gives a nice cask flavor. If you’re using oak cubes, remember that there is a lot of oak in the cube that is nowhere near the surface, so you need more. 3 ounces of cubes is about the equivalent of 1 ounce of chips.
You can use oak in either primary or secondary. I prefer secondary because I want them in for 2 weeks, and my beer doesn’t live in the primary that long. Oak commonly comes in packages that are not well-sanitized, so I usually pasteurize them before I put them in the beer. All that takes is 15 seconds in water over 161 F.
I usually do a 3-week secondary, so I actually add the oak to the secondary after the beer has been in it for a week. You really don’t want to leave the beer on the oak too long, so if you can’t bottle it within two to two-and-a-half weeks, you’ll need to move it to a tertiary.
Beer is often casked in used barrels, and those barrels may have been used for other beers, for wine, or for whiskey. To simulate used barrels, try this. First, wash and sanitize a funnel, a beer bottle and a cap. Then, pasteurize your oak and put it in the bottle. Finally, fill the bottle with beer, wine or whiskey and cap it. Let the oak absorb the flavors for a week, then add it to the beer you are making. I’ve had great results with this! Whiskey is so high in alcohol, you can use anything you have, but with wine and beer, you want to open a bottle fresh. You don’t want any bacteria that have nested in that red wine bottle you opened two days ago to get into your beer.
Making cask ales at home is actually super easy! Any store that sells winemaking gear will have lots of options, and you can always order online as well.