Summers in New York City are very humid; the air becomes dense and hard to breathe, like the whole city is steeped in hot garbage tea. The city’s only modes of relief are in-window AC units, happy hours, breezy summer nights, and—you guessed it—lots of iced coffee. 

Immersion cold brewing is adjustable, dependable, versatile, and much easier than the coffee industry lets on; it’s a top contender for the lowest-effort, highest-reward method for home brewing. I keep a pitcher of cold brew on hand through the work week for when I’m too busy to make a pour over, for when I get a sweet coffee craving, or for Fridays, when I get to make coffee cocktails. 

Immersion cold brewing is adjustable, dependable, versatile, and much easier than the coffee industry lets on; it’s a top contender for the lowest-effort, highest-reward method for home brewing.

For the uninitiated, “immersion” refers to the method of brewing with your coffee grounds saturated in water fully and continuously until the end of the brew period. This differentiates it from the cold drip method, which constantly drains and drips new water. The latter, often referred to as “Kyoto-style cold drip” or “Kyoto cold brew” is a delicious but cost-prohibitive cold brew—cold drip towers can cost up to $300 and a regretful amount of kitchen counter space. Immersion cold brew, on the other hand, is simple and dependable, like a wine you’d happily use for cooking and drinking.

There are only a few steps to immersion cold brewing: saturate your coffee grounds with water, let it steep for 18-24 hours, filter, and dilute. Let’s dive a little deeper.

Be sure to use a non-reactive container like a glass jar or plastic pitcher, or a bottle with a built-in infuser like the Hario Filter-In Coffee Bottle*. Ultimately, you’ll get practically the same result with or without a filter at this step, as long as the grounds stay fully saturated—don’t worry about buying new equipment if you already have the basics.

Your biggest barrier to making cold brew at home is grinding your coffee. If you don’t have an automatic burr grinder at home, grinding will be logistically difficult. The last thing you want to do is corner yourself into a surprise workout hand-grinding five times as many coffee beans as you normally would. Coffee Project NY has burr grinders at our online shop, but if that’s too big of a commitment for you, ask your local coffee shop to grind your coffee beans (And tip!). For this method, which utilizes a long and controlled extraction, an extra-coarse grind the size of breadcrumbs will help prevent over-extraction, which causes bitterness.

Use a 1:5 ratio for cold brew (that’s 5 grams of water for every 1 gram of coffee). Because most hot drip coffees are brewed around a 1:15-1:17 ratio, your cold brew is going to be three times as strong as regular coffee. The unfiltered concentrate is very dense and syrupy, so brew with a coffee-friendly water like filtered or spring to keep your flavor profile cleaner and lighter. If you don’t have a kitchen scale, invest in one. An accurate scale is a must for all home brewers and cooks—measuring coffee by volume is highly inaccurate and varies with origin, varietal, grind size, and roast level. It’s an enormous barrier to making good coffee at home. If you can’t afford the price or want to get started without one, trial and error is your best option.

This large-batch brewing takes more effort up front, but less work per cup than manual brewing. Take the time to be thorough and reap the extra rewards in flavor.

Refrigerate your cold brew for better brewing consistency. It provides steadier environmental conditions throughout the process, since ambient room temperature fluctuates with AC units turning on and off, the sun setting and rising, and doors opening and closing. Brewing in the fridge also slows down the extraction process and helps pinpoint the right time to end your brew.

Because extraction is slowed, your brew period should be longer than typical, or about 20-24 hours. This long-brew method allows for better control of your coffee’s flavor profile, so don’t be afraid to taste test throughout the process. When you do, sample it earlier rather than later. You can always give it more time, but you can’t give it less. Try it after 20 hours: if it tastes sour or underdeveloped, it needs more time to brew; your concentrate should taste sweet, syrupy, and strong.

Filter your cold brew* using your biggest pour-over dripper (I use an old cracked V60 02) or, in a pinch, a fine mesh strainer lined with a coffee filter or fine cheese cloth—just be sure to rinse your filter first to remove any papery taste. Try to be patient, because this step takes time and possibly more than one filter! If your cold brew is still muddy or still has grinds in it, filter it again. This large-batch brewing takes more effort up front, but less work per cup than manual brewing. Take the time to be thorough and reap the extra rewards in flavor.

Dilute! The strong brew ratio gives you the freedom to dilute your concentrated coffee to your own taste. If you don’t know where to start, try a 1:1 ratio of concentrate and filtered or spring water. If you want to have some extra fun, try diluting your cold brew with milk, tonic water, Coke, or lemonade! Store it as a concentrate in the refrigerator for up to a week.

For cold brew experts who want to experiment with extraction (and especially for those who avoid cold brew because it doesn’t showcase terroir or acidity), try blooming your coffee hot and then immersing it into ice water to bring down the temperature. The reason cold brew can be so uniformly sweet and lacking in complexity or fruitiness is that a lot of acids are only released from coffee at high temperatures. Since acids are the first to be extracted while brewing hot, a simple hot bloom can go a long way for the character of your cold brew. Play around with this method for fruity light roasts or anaerobic coffees, and fall back in love with cold brew.

*Cold brewing “filter-in” eliminates this step completely, which is what gives a dedicated cold brew infusion pitcher its appeal—just pull the infuser or bag of coffee out, let it drain, and you’re good to go. However, if you’re brewing with your coffee filter-in, avoid metal filters; they are reactive and don’t filter out oils and fats from the coffee. Be conscious of the size of your infuser, too, which is sometimes made too small for specialty cold brew ratios. Often, your batch won’t fill the entire pitcher even if your infuser is full.