The Ultimate Toddy Cold Brew Guide: Ratio, Grind Size, and Overnight Rituals

There is an old culinary adage that time is an ingredient. In the frantic rush of modern mornings—where calendar alerts ping before the alarm clock has even finished its opening monologue—time is the one ingredient nobody seems to have in surplus.

Enter the art of the make-ahead ritual: cold brew coffee. Not the watery, over-extracted iced coffee born from pouring scorching hot drip coffee over melting ice cubes, but true, slow-steeped cold brew concentrate. Velvety, chocolate-forward, naturally sweet, and boasting roughly 67% less acidity than traditional hot extraction.

While trendy gadgets come and go, one system has quietly reigned supreme on kitchen countertops and specialty cafe back-bars since 1964: the Toddy Home Cold Brew System.

Here is our comprehensive, zero-pretension masterclass on mastering the Toddy system—complete with the golden ratio, grind specs, and the secret to a week’s worth of effortless morning parent fuel.

Why the Toddy System Remains the Undisputed Heavyweight

Invented by chemical engineer Todd Simpson over six decades ago, the Toddy system relies on a deceptively simple principle: full-immersion cold water extraction combined with gravity filtration.

Unlike rapid flash-brew methods or immersion jars that require messy cheesecloth gymnastics, the Toddy system uses a non-electric brewing container paired with a heavy-duty reusable felt disc and optional circular paper filters. Because the coffee grounds never encounter heat, the harsh, astringent chlorogenic acids remain locked inside the bean, while the smooth, soluble sugars and aromatic oils are gently coaxed out over 12 to 24 hours.

The result is not just iced coffee; it is a rich, versatile coffee concentrate that keeps inside your refrigerator for up to two weeks without oxidizing into stale bitterness.

The Equipment Checklist

To brew a classic batch at home, gather the following:

  • The Brewer: Toddy Home Cold Brew System (brewing container, glass decanter, silicone lid, and rubber stopper).
  • The Filtration: Toddy Reusable Felt Filter, plus an optional Toddy SB Paper Filter for ultra-clean sediment-free pouring and effortless cleanup.
  • The Coffee: 12 oz (340g) of freshly roasted, coarse-ground specialty coffee. We recommend our dedicated cold brew favorite, A Midsummer Night's Blend, or the deeply chocolatey Bali Blue Single Origin.
  • The Water: 56 oz (7 cups / 1.65 L) of cold, filtered water.
  • A Digital Scale or Measuring Cup: For repeatable brewing precision.

The Golden Ratio & Grind Size

Precision matters, but snobbery does not. Here is the math that delivers the perfect concentrate every time:

The Toddy Concentrate Ratio: 1 part coarse coffee to roughly 4.7 parts water by weight (or 12 oz coffee to 56 oz water).

The Grind Size: Think Coarse Sea Salt

If there is one cardinal sin in cold brewing, it is grinding too fine. Standard pre-ground supermarket coffee is sized for automatic drip machines. If you pour drip-grind coffee into a Toddy brewer, two unfortunate things will happen: the water will over-extract into a muddy, bitter slurry, and your filter disc will choke during drainage.

You want an ultra-coarse grind—resembling coarse sea salt or raw demerara sugar. The large particle size allows water to circulate freely between the grounds, promoting uniform extraction while allowing the brewed concentrate to drain cleanly into the glass decanter.

Step-by-Step Brewing Protocol

Step 1: Set the Stopper & Dampen the Filter

Insert the rubber stopper firmly into the outside bottom of the brewing container. Take your round reusable felt filter, submerge it in clean cold water, squeeze out the excess, and press it flat into the circular recess inside the bottom of the container.

Pro Tip for Painless Cleanup: If you are using a Toddy SB Paper Filter Bag, open the paper bag inside the container so it rests directly on top of the felt disc. At the end of the brew, you simply lift the spent bag out and toss it into the compost.

Step 2: The First Pour (The Ground Foundation)

Pour 1 cup (8 oz) of cold filtered water into the bottom of the container. Add 6 oz (roughly half) of your coarse-ground coffee. Slowly pour 3 cups (24 oz) of water over the grounds in a gentle spiral, ensuring all grounds are saturated. Wait five minutes to let the coffee bloom and settle. Do not stir. Stirring can push fine particles into the felt filter and restrict drainage.

Step 3: The Second Layer (The Crown)

Add the remaining 6 oz of coarse coffee grounds. Very gently, pour the remaining 3 cups (24 oz) of water across the top layer. Use the back of a soup spoon to gently press any dry floating grounds beneath the surface of the water until thoroughly saturated.

Step 4: The Overnight Patience (12 to 24 Hours)

Cover the brewer with the Toddy lid. Now comes the easiest step: walk away. Leave the brewer on your kitchen counter at room temperature for 12 to 24 hours (16 to 18 hours is the sweet spot for peak sweetness and milk chocolate depth). Do not agitate or jostle the container.

Step 5: The Decanting Ritual

When steep time is complete, remove the rubber stopper from the bottom of the brewer and immediately set the container on top of the glass decanter. The deep, dark coffee concentrate will begin flowing through the filter. Gravity will take 20 to 35 minutes to drain completely.

Seal the glass decanter with the silicone freshness lid and store it in your refrigerator. Rinse your felt filter thoroughly under warm water (never use soap!), place it in a sealed zip-top bag with a splash of water, and keep it in the freezer until your next brew.

How to Serve Your Concentrate

Remember: this is a potent, full-strength concentrate. Drinking it straight is an adventure best reserved for marathon runners and emergency room physicians. For the rest of us, dilution is where the magic happens:

  • The Classic Iced Cold Brew: Mix 1 part concentrate with 1 part cold filtered water. Pour over a tall glass packed with fresh ice.
  • The Velvety Cold Brew Latte: Mix 1 part concentrate with 1 part creamy oat milk, whole milk, or almond milk. The natural sweetness of the cold extraction pairs exquisitely with dairy and plant-based fats.
  • The Smooth Hot Cup: Boiling water over cold brew concentrate? Absolutely. Mix 1 part concentrate with 2 parts piping hot water for an ultra-smooth, low-acid hot morning coffee that will never upset a sensitive stomach.
  • The Espresso Martini Base: Because of its thick body and lack of bitterness, Toddy concentrate makes the definitive bar-grade base for craft coffee cocktails.

Best Brewtay Roasts for the Toddy System

Cold water extraction highlights chocolate, stone fruit, caramel, and nutty flavor compounds while muting sharp acidity. Our favorite beans for the Toddy brewer:

  1. A Midsummer Night's Blend: Our signature cold brew blend. Smooth, chocolate-rich, and engineered specifically for long overnight extraction.
  2. Bali Blue: Dark chocolate, brown sugar, and molasses notes that turn into an almost dessert-like cold brew concentrate.
  3. The Morning Tale: If you prefer a brighter, crisper cold brew with hints of crisp apple and toasted almond.
  4. Fairtrade Peru Decaf: 100% Swiss Water Process decaf. All the velvety cold brew richness for evening sipping with zero caffeine jitters.

Frequently Asked Questions

Should I steep my Toddy in the fridge or on the counter?

Room temperature is best. Steeping at room temperature (68°F–72°F) allows for full, balanced extraction in 16 to 18 hours. If you steep inside a cold refrigerator, the low temperature slows molecular extraction, requiring 24 to 28 hours to reach the same level of body and sweetness.

Why is my Toddy draining so slowly?

A slow or stalled drain is almost always caused by either: (1) using coffee ground too fine, or (2) vigorous stirring that forced fine grounds into the pores of the felt filter. Always grind coarse, pour water gently, and avoid stirring the bed.

How long does the concentrate stay fresh?

Kept sealed in the glass decanter inside your refrigerator, Toddy cold brew concentrate stays remarkably fresh for up to two weeks without souring.

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