The Spike (Cold) Brew Kettle

When the Caffeine Hits Just Right  

3 min read 

Besides making beer, our kettles can be used for making many other things. We have customers that roast nuts, mix paint, make elderberry syrup, and do who-knows-what in government labs. My personal favorite alternative use is making cold brew coffee. At Spike, I am known for being a tad particular about my coffee. In the summertime, I make batches of cold brew for our taproom to keep the team well caffeinated with a cool drink on the hottest days. 

Overall, it is a pretty simple process. I use our 15- or 20-gallon kettles to make 10 gallons of cold brew. Whatever batch size of beer you make in your kettle, you can also make the same batch size of cold brew. 

The Perfect Blend  

The first thing to decide is which coffee to use. Technically you can use any coffee to make cold brew, but you get what you pay for. That big container of ground coffee from the supermarket will not give you the best results. I recommend finding a local coffee roaster and getting a medium to dark roast bean. If you go dark, I would avoid any French roast (even if it's in a blend) because it will be too harsh. Make what you like though—except French roast...it’s gross.  

You can also make a small test batch first. A simple test batch can be to mix water and coffee grounds in a container then wait 24 hours and filter out the coffee with a cheese cloth or fine strainer. Pro Tip: use a French Press if you have one. If you have a kitchen scale, do a 1:10 ratio of coffee to water. You can also do 5 tablespoons of ground coffee to 10 fluid oz of water. 

Got your coffee selected? Cool. Let’s brew! 

The Process  

• Add water to a kettle. My preferred ratio is 1 lb. of coffee to 1 gallon of water (roughly equal to the 1:10 ratio above). This will be on the stronger side but not super concentrated. You can dilute it later if you want to, but the Spike team prefers the level of punch this provides. 

• Put coffee in a bag – something disposable makes clean up easier but if you have a bag from a BIAB setup that will work well too! Have the coffee ground as course as possible. This will keep the grounds from getting through the bag. 
• Place the bag of coffee in the water. Cover kettle with lid. 
• Optional: If you have our false bottom, place it on top of the bag to help keep it submerged. 
• Wait 24 hours and remove the bag. 
• Drain the cold brew into a keg and serve it on nitro (30-40 psi) 

• Optional : use a lid like this on your keg to absorb more nitrogen into the cold brew when serving. This helps with the classic nitro “waterfall” effect. 
• Wait for the keg to cool down and enjoy! If the coffee is too strong for your taste, you can always add water at this point to dilute it as you wish. 

I like to keep simple syrup and milk in our cooler for people to add to their own glass. This lets people adjust the flavor to their liking. If this is just for you, you can certainly add milk and simple syrup straight to the keg.  

Mike Cymerman is the leader of the Customer Experience team. He works tirelessly to make sure your Brew Day runs as smooth as possible. He's also one of the longest tenured employees at Spike and the office's self-appointed coffee expert.