Brewing larger volumes of coffee at home can be challenging. As you increase your brew weight, you need to correspondingly tweak other variables, including your grind size and brew ratio.
For less experienced home brewers, it might be tempting to just add more water and coffee. But this can lead to uneven extraction and lower quality in that final cup.
To learn how to avoid this, I spoke to three baristas and coffee competition champions. They shared some recipes and best practices for brewing larger volumes of coffee at home. Read on to find out what they said.
You may also like our article on recreating a coffee shop cappuccino at home.
There are many ways to brew coffee, but as you increase the quantity you’re brewing, you need to change a number of variables.
The simplest way to do so is arguably to use a batch brew machine (also known as an automatic drip machine). In theory, however, any manual brew method can also be used to make larger batches of coffee.
When you do manual brew at large volumes, however, it’s important to adjust your brew variables. If not, simply adding more water and increasing your brew time means you run the risk of overextraction.
In addition, exposing ground coffee to high temperatures for longer periods of time can also diminish its more delicate flavours and aromas, as well as creating a thin or watery mouthfeel.
Changing these variables is also not as simple as just multiplying measurements (such as doubling the ratio of dose to yield). It often requires experimentation and finesse. Each individual brewing method should be treated differently, and the baseline recipes for each will need to be changed as such.
Daniel Horbat is the 2019 World Cup Tasters Champion and owner of Sumo Coffee Roasters in Dublin. He says that as well as helping him fine-tune extraction, his home brewing recipes for larger volumes of coffee help him save time.
“I created some recipes so I don’t have to waste time,” Daniel says. “I can do other things inside the house [while the coffee is brewing] and get really good results.”
Roosa Jalonen is the 2018 Finland Cup Tasting Champion, Q Grader and roaster, and Head of Production at The Gentlemen Baristas in London. “We all have different needs for the quantity and quality of the brew we want to achieve,” she explains.
Ultimately, she thinks the easiest way to brew larger quantities of coffee is to use a batch brewer or large French press, but notes that “it all depends on your personal preferences and needs”.
Some initial changes for all brewing methods
According to Roosa, the best way to start your recipe is by defining the ratio of coffee to water, as well as the total brew time. Generally, she uses between 60 and 75g of coffee per litre of water; however, the ratio can change according to the coffee you use, as darker roasts are more soluble.
However, no matter the brewing method you use, larger volumes will always benefit from a coarser grind than usual. This is to compensate for the extended extraction time.
Roosa says that finding a middle ground with grind size is important. “Too fine a grind may result in a very bitter cup,” she says. “If it’s too coarse, however, your coffee might taste weak and flavourless.”
Grind size tips
Firstly, Daniel says that no matter how much coffee you’re brewing, you should grind fresh. This is because coffee releases between 60 and 70% of its carbon dioxide within a few minutes of grinding. This leads to a significant loss of flavours and aromas.
For his larger manual brews, Daniel uses a grind size close to granulated sugar (the coarser side of medium). The brew ratio for this, he says, should be around 60g of coffee to 1 litre of water. At higher volumes, however, you will want to go even coarser.
If you’re using a stepped electric grinder, you can check online for the best setting for your brew method, and then adjust the setting accordingly. It may take you a few attempts to dial in the best grind size, but you can then extrapolate that for larger or smaller volumes as necessary.
Daniel brews with a Kalita Wave, using FP102 white Kalita paper filters, and prewets his filters with cold water before brewing to remove the papery taste. His brewing water is heated to a temperature of 95°C.
While agitation is common practice for brewing pour over coffee, Daniel says that it isn’t always necessary to stir or swirl at larger volumes.
“This way you produce more turbulence, and you might overextract the coffee,” he says.
Tips for brewing larger quantities with manual brewers
While you can brew larger quantities with manual brewers like the French press, Chemex, or pour over drippers, it isn’t always easy. Achieving consistent, optimal results with these manual brewing methods can be challenging, especially if your brewer is smaller than you might need.
Let’s take a look at a few popular manual brewing methods, and some tips for batch brewing with each.
Pour over drippers
First things first: know your brewer shape. Flat bottom brewers, such as the Kalita Wave, extract coffee differently to conical drippers like the V60.
The difference in shape ultimately affects how the brewer extracts flavours and aromas from the coffee: flat bottom drippers tend to highlight sweet and floral notes, while conical drippers enhance citrus and berry notes, as well as overall acidity.
Kaley Gann is the 2019 US Brewers Cup Champion, an ACE-certified trainer, and Retail Manager at Ceremony Coffee Roasters in Maryland. She tells me that using a coarser grind for conical brewers will bring out the best of sweeter coffees and medium or dark roasts. It will also help to prevent some of the more bitter flavours from being extracted.
She agrees that flat bottom brewers are better at highlighting a coffee’s more complex and delicate tasting notes. This, she says, is because they have a better flow rate than conical brewers, so water can pass through more easily and extract more flavours from the cup.
“A finer grind [for flat bottom drippers] works well to maintain balance in the cup,” Kaley adds.
Daniel, however, doesn’t agree. He says that coarser grinds work better for flat bottom brewers. He also doubles up his filter papers for more clarity, sweetness, and balance.
Ultimately, he says that changing brewing variables for pour over coffee is a case of trial and error. Adjustments need to be made accordingly.
“[Start by] playing with the grind size,” Daniel says. “If you use 30g coffee to 500ml water, use a medium grind. For 60g to 1 litre, use a medium-coarse grind. For 120g to 2 litres, go even coarser.”
Keep in mind that with smaller pour over brewers like the V60, Kalita, and the small 3-cup Chemex, extracting larger quantities may be difficult. In many cases, these standard models often only accommodate around 30g of coffee.
Larger pour-over brewers, such as the 6 to 10-cup Chemexes, are ideal for batch brewing. Kaley says that with the Chemex, you should start with a brew ratio somewhere between 1:14 and 1:17.
“If you’re using a Chemex and scaling up the brew size, add more coffee to fit that ratio and then coarsen the grind,” she says.
Moka pot & AeroPress
For smaller moka pots and the AeroPress, brewing americano-style beverages can help to increase the volume of your brew.
A good place to start is calculating the volume of water that your moka pot or AeroPress holds, and heating the same volume again to 70°C in a separate receptacle. Once the initial concentrated coffee is brewed, you can dilute it with the hot water in a separate receptacle.
This technique is called “bypassing”, and can be used to control extraction and flavour profile when brewing larger batches of coffee.
Kaley says that because the French press is an immersion brewing method, you don’t need to change the grind setting, even as your brew size increases.
This is because immersion and percolation are two fundamentally different types of extraction, which yield different flavour profiles.
She recommends starting with a similar brew ratio to the Chemex (somewhere between 1:14 and 1:17) and dialling it in to taste.
What about batch brew machines?
Beyond manual brewing methods, some home consumers may choose to use batch brew machines. These are designed to brew (and often store) multiple cups of coffee.
However, Kaley notes that extraction quality varies from machine to machine.
“I like a machine that can replicate a good cup [of] drip coffee that I can get at my café,” Kaley says. “I use a Moccamaster. It’s a great drip machine that brews a larger batch quickly without sacrificing the complexity of the coffee.”
Some automatic filter brewing machines, like the Moccamaster, allow the user to change extraction variables for each new coffee. However, Kaley notes that not all drip brewers are created equal, and not all will have this functionality.
“The Moccamaster regulates temperature well, but every drip machine is different. Check with the manufacturer of your machine to confirm at what temperature it brews coffee and to see if you are able to manipulate it at all,” she advises.
Kaley’s go-to recipe for the Moccamaster is 70g to 80g of medium-coarse ground coffee for 10 cups. She says this is a good starting ratio that can be easily manipulated, depending on the roast profile.
“For more developed or darker roasts, I start at around 80g; for lighter, brighter roasts I start at 70g,” she tells me.
If the coffee tastes too bitter, she recommends grinding coarser to minimise overextraction. Alternatively, if the brew has an unbalanced or sour taste, grinding finer will help to extract more sweetness and bitterness, creating a more rounded coffee.
Brewing larger quantities of coffee at home can be difficult without the right equipment. Home coffee consumers shouldn’t assume it’s as simple as multiplying the numbers on their usual brew recipe.
Figuring out which brew method you’re going to use is a good first step, but whether you go automated or manual, there are recipes and techniques that you can use.
While standard recipes for home batch brews provide general guidance on how to achieve good-quality results, these recipes will ultimately need to be tweaked. Experiment with different coffees, roast profiles, and grind sizes until you perfect that cup profile.
Enjoyed this? Then read our article on how to improve your batch brew coffee.
Photo credits: Hendrik Pretorius, Carlos Santana
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