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Spike | Cold Brew Coffee

How to Make Large Batches of Cold Brew Coffee

by Mike Cymerman

4 min read 

While Spike homebrew kettles are best known for brewing beer, they can also be used to create large batches of cold brew coffee for large-sized groups, companies and events. While cafes and coffee roasters use our kettles to make large batches of cold brew for their customers, we use the OG Kettle here at Spike to keep our office and manufacturing teams well caffeinated on hot days. If you’re ready to learn how to make large batches of cold brew coffee that your customers, co-workers, friends, and family will love, then you’ve come to the right place.

How to Make Cold Brew Coffee Step-by-Step Instructions

Spike homebrew kettles are large enough to produce 5 to 30 gallons of cold brew coffee. To put that in perspective, 1 gallon of cold brew is usually enough to serve at least fifteen 8oz cups. Needless to say, you’ll be able to make more than enough for small to large sized offices, parties, and all sorts of events by following these simple steps:

Step 1: Choose Your Coffee Bean 

The first thing to decide is which coffee bean to use. Technically you can use any type of coffee bean to make cold brew, but you tend to get what you pay for. So even though you might save a few bucks buying that big container of generic ground coffee from the supermarket, it will not give you the same clean taste as beans selected from a craft coffee roaster. But not all coffee beans from your local coffee roaster are the same. While I prefer a balanced medium roast, you might prefer a darker (more “roasty”) or lighter (more acidic) roast. Generally, for larger gatherings, a medium roast is preferred. However, local coffee roasters often have a variety of flavours to choose from, and I’ve found that talking to the roaster directly is the best way to select the right bean for your cold brew coffee. The last thing to remember when selecting your coffee beans is the grind. Whether you purchase whole coffee beans and grind them yourself, or purchase the coffee pre-ground, the grind can range from very coarse to very fine. When making cold brew coffee, a coarser grind is best so the grounds stay in the bag. 

Step 2 : Make a Small Test Batch 

This step is optional. Before making a large batch of cold brew for the whole office, make a small batch for a quick taste test. This is an easy process that takes about a day to complete:

1. The easiest method is to mix water with your coarsely ground coffee in a small container. For every 5 tablespoons of coffee, add 10 fluid ounces of water. Pro Tip: use a French Press if you have one. 2. Seal the container and let it sit for 16 hours3. After 16 hours, remove the grounds by pouring it through a cheese cloth, coffee filter, or fine strainer or push down on the French Press plunger if you used one.4. Place the small batch into the fridge for an hour to get it nice and cold.5. Pour yourself a glass of your fresh cold brew coffee and flavour as desired with sugar, cream, or syrups. If you’ve brewed enough, you may want to allow a few people to sample the coffee to get their opinions. If it’s too acidic, try a darker roast but if you find it’s tasting almost burnt, a lighter roast may be best.

Step 3: Gather Your Equipment 

After selecting your final coffee roast, it’s time to gather the rest of your equipment. While we’ve included a list of everything you’ll need below, we’ve also created our own Spike Cold Brew Coffee Kit so that you can gather all your supplies with the just one click of your mouse. 


What Equipment Is Needed for Making Large Batches of Cold Brew Coffee?

Included in the Spike Cold Brew Coffee Kit, you’ll find everything need to make 5 gallons of cold brew minus the coffee.

  • 10 Gallon OG Spike Kettle with lid
  •  Valve
  • Barb fitting (to connect silicone tubing)
  •  Silicone Tubing (draining into your serving vessel)
  • Cold Brew Filter Bag (to hold the grounds)
  • Pipe Tape (attaching the valve to the kettle)
  • To put the kit together, you’ll need to make sure you also have an adjustable wrench, which is not included with the Kit.

How Much Coffee and Water Is Needed to Make 5 Gallons of Cold Brew Coffee?

Generally, if you want to five gallons of cold brew coffee, you’ll need 5.5 gallons of water and 5 pounds of coarsely ground coffee. The extra water will be absorbed by the grounds.

Step 4: Set up your Spike Cold Brew Coffee Kit 

Now that you’ve gathered all your equipment together, it’s time to put it all together. Don’t worry, it only takes a few steps:

1. Clean your new kettle and all other parts with hot water and dish soap. Then rinse thoroughly with hot water to ensure no soap is left on the any part of the kettle or brewing equipment.


2. Wrap the threads of the ball valve with Teflon tape to ensure a tight seal. 

3. Screw the valve into the kettle port, then tighten with a wrench. 

4. Wrap the threads of the barb with Teflon tape.

5. Screw the barb into the valve, then tighten with a wrench. 


Step 5: Prepare a Large Batch of Cold Brew Coffee 

You’ve selected your coffee, set-up your equipment, and are now ready to prepare a large batch of cold brew coffee. Just follow these eight steps below:

 1. Add 5.5 gallons of cold tap water to the kettle. 

2. Put 5 pounds of coffee grounds in 1 Cold Brew Filter Bag.

3. Tie the bag at the top so the grounds stay loose in the bag which is better for extraction and place it in the water. 

4. Cover kettle with the lid.

5. Wait 16 hours then remove the bag.

6. Attach tubing to the barb and place a serving vessel beneath the tubing. Open the valve to drain. You can use just about anything as a storage vessel. 

7. Place your vessel in a fridge overnight.

8. Once cooled, you’re ready to serve the cold brew. Remove it from the fridge and prepare it for serving. You may need to place the cold brew into a new container to ensure that it can be easily poured into a cup or glass for individual consumption.

Pro Tip: Make sure you have simple syrup and milk available for people to add to their own glass of cold brew. You can even bring a few flavored syrups to let your co-workers, friends, family members, and others add a little hint of hazelnut, chocolate, vanilla, or amaretto. This lets people adjust the flavor to their liking.

A Few Helpful Tips for Making Cold Brew Coffee

If you’ve made it this far, then you know how easy it is to make cold brew coffee with our Spike Cold Brew Coffee Kit. However, there’s a few issues that we’ve found our customers often face, and we wanted to offer a few tips to help you overcome them.

Cold Brew Coffee is Too Strong or Too Weak

First, you might find that your coffee is way too strong or acidic. This usually means that the coffee to water ratio isn’t quite right and that you need to use a little more water or a less acidic coffee. It’s also possible your coffee grind is too fine and you need to grind a bit coarser. On the other hand, the cold brew may come out too weak. Usually, you just need to add some more coffee grounds or decrease the amount of water you’re using. Our team uses a weight of coffee to weight of water ratio of 1:10, but sometimes this needs to be altered for individual preference.

Not Enough Room in the Fridge?

Sometimes it can be downright impossible to fit a 5 gallon container in your fridge. One way around this is to decrease the amount of cold brew coffee you’re making. However, that’s not always the best fix because it means you might not have enough left for everyone come serving time. A better option might be to use several vessels. While a single 5 gallon vessel might be too large to fit in the fridge, you might be able to find a way to fix multiple 1 or 2 gallon containers more easily.


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.