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australia:coffee

the perfect coffee when camping

the lazy camper's coffee

  • buy ready made cappucino sachets, just add hot water and stir, no need for added milk

"expresso" coffee makers for camping

classic aluminium moka pot

  • great for simplicity, price, ergonomics and durability but low pressure 1 to 2 bar (100 to 200 kPa) so minimal crema
  • need to follow the process:
    • water to just below the level of the valve
    • coffee grinds to fill the coffee chamber evenly to the top without leaving air spaces but generally does not need to be tamped
    • coffee chamber must be perfectly sealed without dents as these will allow steam to bypass the coffee and you will just get water in the percolate
    • top part of the pot must be firmly screwed in place to ensure optimum seal
    • heat should be medium only to avoid too rapid a percolation process

Bialetti Brikka high pressure aluminium moka pot

  • incorporates a weighted valve as a pressure regulator on top of the nozzle that allows pressure to build up inside the water tank in a manner similar to a pressure cooker.
  • As pressure builds up more quickly in this method (since there is much less leakage of vapour) compared to the standard moka pot, it reaches the level required for water to rise through the ground coffee in a shorter time. However, the weighted valve allows pressure to accumulate and temperature to rise somewhat further before the liquid bursts through the nozzle.
  • The result is coffee brewed at a higher pressure and temperature than the standard pot, making it more similar to espresso and therefore with more visible crema, but still not the same as a pumped expresso.

Campfire Compact Expresso Maker

  • hard anodised aluminium 2-3 cup (350mL) with a dripping spout and silicone detailing
  • cons:
    • 3x price of a moka pot
    • spout is likely to be damaged unless unscrewed but doing so risks losing the tiny plastic washers
    • no handle and the silicone is not wide enough to allow safe handling while hot and the unit remains hot for quite some time necessitating the use of oven gloves to handle (although theoretically it does fit inside a Furno camp pot so this may be a workaround)
    • dripping coffee sprays all over the place in windy conditions
    • rubber gasket fits loosely on the filter mesh and is annoying to re-fit each time
  • personally I would not recommend for camping despite it looking cool

Wacaco Nanopresso Portable Espresso Maker

  • incorporates a manual pump to give a maximum of 18 bars (261 PSI) of stable pressure during extraction
  • works best with finely ground coffee that is tamped hard
  • 80mL boiling water must be added to chamber
  • 336g
  • optional NS Adaptor for Nespresso-type pods

Wacaco Minipresso NS Portable Espresso Maker

  • NS version uses Nespresso-compatible pods
  • GR version uses ground coffee
  • incorporates a manual pump to generate 8 bar which is sufficient psi to give crema
  • uses 70mL boiling water
  • 350g
  • I would recommend doing 1 or 2 runs with boiling water without coffee to heat it up so your expresso is not too cold

Aeropress

  • perhaps the best option as it is light, easy to clean, unlikely to break, relatively compact and simple to use to make a reasonable expresso or Americano but you won't get crema
  • only 226g and is 14x11x10cm (excluding paper filters and filter holder and funnel
  • works best with finely ground light roast coffee and there are many recipes such as:
    • Expresso:
      • as per Aeropress directions, 1 heaped spoon (14g) add 80degC water to the 1 marker, stir for 10sec, then insert plunger and plunge gently
      • if making a cold brew do the same but use cold water and stir for 1 minute not just 10secs
      • convert hot expresso to Americano by adding hot water to fill a 237mL mug
      • convert hot expresso to Latte by adding hot milk to fill a 237mL mug
    • Americano:
      • James Hoffman's fine ground “ultimate” method:
        • 11g coffee, add 200g water at around 95degC (90degC for medium roast and 85degC for dark roast), ensure you put the plunger in immediately to create a vacuum and allow time for the water to extract from the coffee for 2 minutes then gently shake to allow floating coffee to settle, wait 30secs then very gently plunge
      • coarse ground inverted methods
        • 30-35g coarse ground coffee onto the plunger which is inside the inverted tube
        • initial 100g 80-94degC water
        • stir vigorously for 10-20sec
        • add further 100g water either at this point then stir again for 10secs or as a dilution later
        • total brew time 60-100secs
        • add the rinsed paper filter and filter holder
        • invert then plunge
        • allow to cool to 60degC
  • optionally get a coffee storage container designed to fit inside the Aeropress:
  • optionally match it with a hand grinder that fits inside it such as the:
  • if you have money to spend and more space and don't mind more weight, consider the 1Zpresso JX-Pro or the very expensive Kinu M47 hand grinder

the expresso coffee process

  • roasting the beans
    • slower roasts tend to minimise the unwanted movement of oils to the surface of the beans where they would be exposed to oxidation and rancidity
  • degassing the roasted beans
    • most taste better when allowed to degas for 2-5 days after roasting - the optimum time depends on a range of factors
      • natural coffees need longer times to degas than washed
      • a dark roast accelerates degassing because the bean has degraded more
    • using it too soon after roasting, the very high CO2 levels prevent the percolating water interacting with the ground coffee, this is particularly an issue with short brew times such as when pulling an expresso, but less of an issue with longer brew techniques
    • too much degassing results in less vibrant flavours (labile coffee aroma escapes with time and combined with exposure to UV light and oxygen which can degrade the coffee oils making them rancid and stale and this process is faster at higher temperatures and at higher humidity) and less crema
      • chemical freshness relates to the aroma changes in coffee
        • coffee consists of perhaps 40-50 key aromas, each behaves differently, and often the same compound can have a positive and negative smell attribute, which changes only with its concentration
        • for each coffee, there will be a different peak concentration of each of these aromas for the optimum experience. The extraction method plays a role, and the optimum might be different if we use the coffee for espresso or for filter coffee
        • for instance after 2 weeks, there may only be 20% of the methanethiol left and 80% of the methylpyrazine left
        • storing coffee in the freezer will prolong the coffee freshness for about 10-times, but it should be within a sealed container so that humidity and smell from other food in the freezer does not migrate into coffee beans. When using, allow 1-2 hours for the container to reach room temperature before opening.
      • physical freshness relates to the degassing changes
        • 1% of freshly roasted coffee beans consist of CO2 and it takes 1-2 months for this to be fully released
  • grinding
    • coarsely ground beans retain more gas and provide more crema but may have less flavour
    • the sooner it is brewed the better
    • it can be stored up to a week in a sealed container at low temperatures but longer storage should have vacuum sealing or similar
    • plunger coffee machines or percolators generally require coarse ground coffee however the Aeropress works best with finely ground coffee similar to expresso makers
    • very finely ground coffee tamped down increases the contact time with water as well as surface area but needs more pressure (eg. 9 bars) and runs the risk of channels forming creating increased bitterness due to lcalised over-extraction
    • too coarse and one may have sour coffee, too fine and it may be too bitter
  • making the expresso coffee
    • 9 bar (900 kPa) is the usual “ideal” pressure (range is 8-18 bars) with water at 91–95 °C to make an expresso coffee hence moka coffee at only 1-2 bar is not really expresso and has a different flavour characteristic to expresso

crema

  • crema is the brown foam on top of the expresso which is formed from the release of carbon dioxide from the roasted coffee beans into the pressurised steam (low pressure moka pots tend not to form much crema) which is released from the de-pressurised water as it percolates up and then trapped as bubbles within a surfactant created by melanoids and other hydrophobic lipid molecules
  • the crema tends to have the most bitterness and this is in part to it often containing coffee bean particles, and many prefer to scoop it off
  • crema tends to be a sign of a well made expresso
  • crema is maximised by:
    • high pressure percolation
    • coffee grinds with high CO2 content:
      • robusta beans (~3x more CO2 than arabica beans) which have been roasted longer (eg 15 minutes instead of 5 minutes) and darker
      • coarse ground grinding rather than fine ground
      • room temperature degassing rather than 40degC degassing
      • freshly roasted (after 3 days degassing) coffee and freshly ground
australia/coffee.txt · Last modified: 2022/04/26 08:22 by gary1