Commercial Barrel-Aging

December 16th, 2021

It’s no secret that used bourbon barrels are some of the most popular for aging beer. The vanilla, spice and oaky flavors pair so well with imperial stouts, barleywines and strong ales.

While there’s no shortage of exploration and experimentation to be done with bourbon barrels, many brewers have found that there’s another type of barrel that delivers incredibly complementary results when used to age beer – maple syrup barrels.

What’s so awesome about maple syrup barrels? Let’s start with the fact that they first aged bourbon, whiskey and even rum. Some even aged beer before the syrup producers got their hands on them. That’s a load of many different, often complex flavors that have been absorbed into the staves just waiting to be explored.

However, as with other types of specialty barrels, there are a few things brewers and anyone else looking to age with used maple syrup barrels should know before embarking on the endeavor. 

One of the most enjoyable aspects of barrel-aging is the variety of complex flavors you can pull from the oak. There’s vanilla, coffee, caramel, chocolate, coconut and more – the list goes on and on!

Add maple syrup to the equation and you’re looking at even more depth and complementary flavors that can end up in a barrel-aged beer. That maple flavor goes hand-in-hand with the chocolate, coffee and other flavors.

Craft beer geeks like us certainly appreciate that attention to flavor detail! 

But before a brewer can get a brew into the hands of their loyal customers, they need to age it. When it comes to maple syrup barrels, there are a few extra factors to consider.

For one, these may need a little special care before they can be filled with beer or other beverages. Because of its high sugar content, maple syrup absorbs the water from the wood through osmosis.

That means they can get a bit on the dry side, which can cause leaks.

We always recommend using the head swelling method to check for leaks before filling with beer. We prefer head swelling because it’s often easier and doesn’t affect the interior as much as filling with water and swelling internally. This is also our go-to choice for swelling used wine barrels, which can often be drier than a bourbon or whiskey barrel.

To head swell, stand the barrel vertically and fill the top end with hot water that is at least 180º F. You will want to let the water sit overnight (or 12 to 24 hours).

In the morning, add more water and keep an eye out for any bubbles that may come from the head. If you don’t see any bubbles, then flip the barrel onto its other head and repeat. If you still don’t see any bubbles, then you likely don’t have to worry about leaks from the joint between the heads and the staves. This is one of the most common problem areas for leaks.

However, if you do see bubbles, then you will want to let the water sit for several hours longer. This will help the wood continue to soak up the water and swell, which tightens the staves and helps seal leaks.  

Ideally, head swelling will tackle any troublesome leaks. However, there could be additional care steps needed to make sure everything is sealed properly.

When this is the case, we have found it helpful to spray the outside with 180º water while head swelling. This helps speed up the swelling process and is effective when leaks might be coming from the side.

If there are still signs of leaking, then you may need to swell by filling the inside of the barrel with water. There will still be plenty of flavor inside once this is finished.

Swelling a barrel

To swell the barrel, set it horizontally on a rack with the bunghole facing up. Fill it a third of the way with 180º water and let it sit for two hours, rolling it back and forth periodically.

Next, add water so that the barrel is now 2/3 full. If you see any leaks, then let it sit with water inside for another one or two hours.

That should do the trick! Drain and fill with your brew as soon as possible. Try not to wait to fill after you have drained out the water. This can increase the risk of contamination.

Post-fill care tip

Though not as common, leaks can still happen after swelling and filling. Using a blowtorch to gum up and crystalize the sugars from the maple syrup is a great way to seal up leaks quickly.

Still having problems? We’ve got more tips for swelling and sealing leaks.

BLiS and Skinny Sticks are the most common maple syrup barrels that we see in our warehouse. Both are quality choices for aging your beverages!

BLiS is one of the most popular names in bourbon barrel-aged maple syrup. These ex-bourbon maple syrup barrels come to us from their facility in Michigan once they’ve been dumped. Before aging maple syrup for about six to nine months, they aged some older varieties of Heaven Hill bourbon – so you know there’s going to be some excellent flavors locked away in the staves.

The other maple syrup barrel we often have for sale is from Skinny Sticks in Wisconsin. Skinny Sticks barrels age maple syrup for a couple months after having first aged bourbon from several different Kentucky distilleries, including Heaven Hill, Buffalo Trace and Willett. 

Now that you’ve read up on everything you should know about maple syrup barrels and aging beer or other beverage types in them, it’s time to get brewing and filling!

Take a look at what types of maple syrup and other specialty barrels we have in stock or contact us for more information about what could be coming soon.