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. However, many baristas and cafe owners are trepidatious about adding them to their coffee program. Batch brewers lack the theatre of a manually brewed pourover and can be wasteful if cafes don’t sell many cups. This article will examine the benefits of batch brewers, explore some recipes and look at some tips to get the most out of your brewer.
What equipment do I need?
The first thing to consider is the size of your brewer. The size of your brewer should correlate 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. 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. Marco have a range of batch brewers that span many sizes.
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.
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.
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.
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.
Getting the best from your brewer
Keep it clean. You should be cleaning your airpots, brew baskets and shower heads with hot water and espresso cleaner at the end of every day and they should be rinsed thoroughly between brews.
Check that it is level. If the brewer, or the brew basket isn’t perfectly level you will be promoting an uneven extraction.
Check the bed depth. The bed depth of your coffee is how high your coffee reaches 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 channeling 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.
Check the water volume. It can be prudent to ensure your brewer is dispensing the amount of water you expect from it. Weigh the output of a brew cycle without any ground coffee to ensure you are getting the desired water quantity.
Have a backup airpot. Having a second airpot will ensure you never run out of servable coffee. Prepare another brew when the first pot is down to a few serves.
Wet your filter papers. Filter papers taste like paper. Rinse the paper with hot water before brewing. This also heats up the filter basket to minimise temperature loss.
Stir the pot. Stratification will occur during the brewing process. Stir the brew upon completion to ensure the flavours are homogenised.
Batch brewers provide a quick, simple and consistent way of serving great tasting coffee with lower cost of goods and labour costs than espresso based coffees.