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How to get your water temperature just right for filter coffee

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Take a moment to think about all the steps that go into creating a high-quality cup of filter coffee. From harvesting and processing to roasting and brewing, there are so many variables involved.

However, when we look at brewing specifically, one of the most overlooked factors is water temperature – which plays a significant role.

In recent years, businesses have started to recognise how important it is to control the temperature when they brew coffee. Let’s look at why water temperature matters so much, and how businesses can leverage technology to manage it more effectively.

How does water temperature affect coffee extraction?

For water temperature when you’re brewing filter coffee, the Specialty Coffee Association’s (SCA) Golden Cup Standard is a good guide. This dictates that at the point of contact with the coffee grounds, the water should be somewhere between 90°C to 96°C.

But why does the temperature need to be within this range? Well, because it affects how quickly the coffee extracts, and as a result, the flavours that make it into the cup.

During the brewing process, many complex chemical reactions occur, all extracting different flavour and aroma compounds. These include:

  • Chlorogenic acid
  • Caffeine
  • Oils
  • Sugars
  • Melanoidins

The extraction of these compounds is directly impacted by the temperature of your brewing water. Hotter water extracts the compounds more quickly and aggressively, and vice versa.

Controlling your water temperature and therefore your extraction rate is crucial, as each soluble compound has a different impact on flavour. However, when you go beyond the temperature range stipulated above, you risk releasing undesirable flavour compounds.

Can you use cold water?

On the other hand, you can also go too cold, but this is a more complex topic. While lower brewing temperatures don’t extract flavour compounds and aromas in the same way, you can still brew delicious cold coffee drinks.

Cold brew is a perfect example of how extending the filter brewing process can compensate for a lower brew temperature. This brewing method allows you to preserve and extract highly volatile compounds – like sugars – that tend to get lost more easily at higher temperatures.

However, certain coffee compounds simply aren’t soluble in cold water, resulting in a very different flavour profile. For instance, cold water can’t extract aromatic oils as easily as hot water, leading to a very different aroma in response.

Controlling temperature – when you brew and when you drink

It’s not just essential to brew filter coffee at the right temperature –  you also need to maintain that temperature throughout the entire brewing process.

Inconsistencies in water temperature for coffee can significantly affect beverage quality – which means an unpredictable flavour profile when you serve a beverage.

As such, more coffee shops and other hospitality businesses are now focusing on ensuring brewing temperatures are more consistent, which helps to avoid these inconsistencies.

At the same time, while keeping the SCA’s water temperature standards in mind is important, brewing temperature isn’t a one-size-fits-all approach. This “optimal” temperature range will vary based on many different coffee factors, including roast profile and variety.

For example, dark roasts are more porous than light roasts, making them more soluble. This means they extract more quickly, while light roasts extract more slowly.

This means that a slightly higher temperature within the Golden Cup range is perfect for light roasts, while a lower brewing temperature for darker roasts helps to avoid over-extraction and bitter flavours.

It’s also worth noting that you can detect various flavours and aromas at different temperatures once the coffee has been brewed. For instance, peak sweetness can be perceived at around 44°C, whereas acidity as well as floral and fruity notes are most prominent between 31 and 37°C.

How do you maintain your brewing temperature for filter coffee?

The key here is to invest in higher-quality equipment to improve precision when brewing filter coffee.

Unfortunately, many automatic drip coffee brewers don’t meet Golden Cup Standards for brewing temperature. Furthermore, many aren’t able to maintain a stable temperature throughout the brewing process.

An imprecise water supply – coupled with poorly-insulated boilers and outdated heating elements – can result in temperature inconsistencies. And while a higher-quality espresso machine can address these fluctuations, it can be tricky to achieve the same consistency and stability with filter coffee.

Which technology should you use to improve consistency for filter coffee?

For coffee shops, the Marco SP9 automatic precision pour over brewer is a great solution to this problem. Its precise temperature controls and pulse brewing technology ensure the water temperature remains within an ideal range as it comes into contact with the coffee.

Beyond coffee brewers, coffee shops, restaurants, and other hospitality businesses should look at investing in new boilers – like Marco’s under-counter MIX and MT ranges. Both are equipped with superior vacuum-insulated tanks that can retain heat for longer. The MIX boilers are also 70% more energy-efficient than other competing brands, helping businesses save on operating costs. The MT boilers, meanwhile, have a minimal countertop footprint and are compatible with hands-free tap adapters. The MT Dual-Tap also dispenses both hot and cold water.

Sites that use the MIX can also further control extraction with the Marco MIX 3B Font. This temperature-controlled water dispensing system can dispense precise volumes of water at three different temperatures.

Ultimately, coffee shops and hospitality businesses can invest in higher-quality equipment to control water temperature more effectively and bring out the best characteristics in the coffees they serve.

This way, customers will get the opportunity to experience your filter coffee at its best, while still ensuring a reliable, efficient, and cost-effective brew bar.

 

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