Filter coffee in Australia has come a long way in recent years. It is becoming less and less common that a barista will be asked about the “science experiment” they are conducting when making a pourover. Simply, having a filter coffee option on a menu is an indicator that a cafe is serious about coffee. A good cup of filter coffee is sweet, complex and provides a clarity of origin notes than can be overwhelmed in an espresso. However, manual filter brewing methods are slow and prone to inconsistencies. If only there was a better way!
Automated batch brewers are fast, consistent and require very little training to master – there’s a lot of great reasons for a café to offer batch brew on their menu. For the café owner, there’s some great profit margins on these low-labour cost brews too, making them a sustainable way to expand your menu.
Many baristas and cafe owners are trepidatious about adding them to their coffee program. Batch brewers lack the theatre of a manually brewed pourover, require investment in some new gear and can be wasteful if cafes don’t sell many cups.
With a little consideration and attention to technique, however, launching a new batch brew program can be a great move. Let’s look at what do you need to get started brewing some delicious brews!
What do I need to get started?
There is a plethora of choices when it comes to batch brewers, each with their own features. A key consideration should be the batch size of your brewer delivers, which correlates to how many cups you are likely to serve. If your brewer is too small, you will constantly have to put on new brews to keep up with demand, reducing the efficiency. If your brewer is too large then your brews sit for too long in your airpot before serving, or you will be forced to brew with a dose that is too small for your brewer (more on this later). Ideally, a brew should be used within 1 hour after brewing. So, estimate how many cups you will serve in an hour and find a brewer that suits. You will get four 8oz cups out of a 1L brew.
Next, consider the features that you might want from your brewer. Look at the shape of the dispersion screen – will it shower your coffee bed with an even distribution? Look at the shape of the basket – flat based baskets will generally provide more even extractions. Look at temperature stability – many brewers have a temperature spike at the end of brewing. Look at how much control you have over brew variables such as water temperature and dispersion time.
For smaller sizes the Moccamaster Classic and the Marco Bru F45M are great options. For extra versatility and control, the Marco SP9 bridges the gap between manual and automatic. It retains the theatre of a manual brew, with the consistency and ease provided through automation. With the SP9 you can choose your brewing device and brew anything from a single cup up to a 750mL carafe of filter coffee.
For venues wanting to deliver larger volumes of batch at once, the Marco Jet 6 makes a minimum of 2ltr and max of 6ltrs at a go!
Next you will need a grinder with burrs suitable for grinding filter coffee, such as the Mahlkönig EK43, the Mazzer ZM or the Baratza Forte (or Baratza Encore for you home brewers!).
Finally, you will need quality water. Using filtered water will result in a better tasting product and will also be better for your batch brewer’s health, avoiding scale build up. Make sure you have easy access to a filtered water tap and measuring jug.
Dialling in.
Dialling in coffee on a batch brewer is similar in many ways to dialling in an espresso coffee. You will be looking for signs of under-extraction and over-extraction and finding the perfect strength. The differences are the variables we have to work with and the volume of coffee that can potentially go to waste.
The variables we can alter in all batch brewers are brew ratio and grind size. Some brewers will allow you to alter the water dispense time/rate and the temperature.
Starting Recipe
Brew ratio: 60g/L (eg 120g of ground coffee and 2L of filtered water)
Grind setting: There is no fixed number for this, but as a general rule the total contact time should be between 5 min 30 sec – 6 min 30 sec. This grind setting will require increasing coarseness the larger your brew is.
Water Temperature*: 96°C
Dispense time*: This should correlate the total contact time above. For a starting point, 4min 30sec for a 2L brew, 15 seconds less for every extra litre.
*Only adjustable on some brewers.
Troubleshooting Basics.
The coffee tastes too weak – Increase the ratio of coffee to water (eg 65g/L)
The coffee tastes too strong – Decrease the ratio of coffee to water (eg 55g/L)
The coffee tastes over-extracted (bitter, dry, astringent) – Make the grind coarser
The coffee tastes under-extracted (sour, too acidic, lacking sweetness) – Make the grind finer
Keep a log-book of your recipes and tasting notes to help yourself and others dial in. Note that just like espresso, you may need to tweak your recipe as your coffee ages.
Getting the best from your brewer.
Keep it clean!
This is one of the biggest (and most basic) mistakes we see in cafes offering batch brew: they’re not sufficiently cleaning their equipment and airpots resulting in a murky, stewed taste. Clean your airpots, brew baskets and shower heads with hot water and espresso cleaner at the end of every day and they rinse thoroughly between brews.
Check your level.
If the brewer, or the brew basket isn’t perfectly level, water will dispense unevenly over your bed of coffee grinds and you’ll end up in an inconsistent extraction.
Check the bed depth.
The bed depth is how high your coffee grinds reach in your brew basket (before brewing). You should aim for a bed depth of between 3-5 cm and alter your recipe around this. A bed depth below 3cm will be more susceptible to channelling and a bed depth over 5cm can require a grind that is coarser than ideal and in some cases can cause the brew to overflow from the basket.
Analyse the coffee bed once your brew is finished.
How high did the coffee slurry rise? If the coffee slurry rises to the edge of the filter paper you have likely used a grind setting that is too fine, restricting flowthrough (read: potential overextraction). If it hasn’t risen much at all, then your grind might be too coarse to maintain a sufficient contact time (read: weak, under extracted brews).
Check the water volume.
It can be prudent to ensure your brewer is dispensing the amount of water you expect from it. Without any coffee in the basket, weigh the output of a brew cycle to ensure you are getting the desired water quantity dispensed.
Have a backup airpot.
Having a second (or third depending on rotation) airpot will ensure you never run out of servable coffee and give you time to appropriately clean between brews. Prepare another brew when the first pot is down to a few serves.
Rinse your filter papers.
Surprise! Filter papers taste like paper. Rinse the paper with hot water before brewing to get rid of this nastiness. This also heats up the filter basket to minimise temperature loss.
Stir the pot.
You’ll naturally get more extraction during the beginning of the batch and less towards the end, resulting in a layering of stronger to weaker coffee within your aipot. Give the brew a stir within the airpot after the brew finishes to ensure a homogenised flavour.
And lastly, and most importantly, Taste your Batch!
Yes, it’s made in volume, and the brewing is predominantly hands-free, but your customers still want something that tastes good. So try your own batch – small sips regularly. Make sure your recipe, your coffee selection and how long since the batch was brewed is still something you’re proud to serve and charge for.
As you can see, the recipe for a successful batch brew program in your café isn’t complicated. Choosing the right equipment, brewing with attention to detail and a focus on quality in the cup with result in a win win for both customers – who get tasty, consistent and speedily delivered coffee – and café owners – who get a cost effective preparation method and an opportunity to diversify their coffee menu. Let the litres of liquid gold flow!
