Vacuum or Siphon
Your guide to vacuum coffee
"Nature abhors a vacuum" - so said the philosopher Aristotle. The same cannot be said of coffee connoisseurs - many of whom believe the only way to make the perfect cup is by the vacuum brewing method. This brewing method (sometimes known as the siphon process or full immersion technique) is gaining popularity thanks to the extra flavour and unique profile that it brings to the drink. It is also a very chic and stylish way of producing a tasty cupful.
It's not a new technique; the idea was patented as long ago as the 1830s by Loeff of Berlin. But it was a Frenchwoman by the name of Fanny Vassieux, from Lyon, who produced the first commercially viable vacuum coffee maker: a machine Deux ballons. The siphon coffee devices have been used for a long time by artisans, hotels, restaurants and coffee shops, but the complicated, rather heavy-duty machines, technique, and price have kept them out of reach of home brewers until recently.
Vacuum coffee makers are now readily available from cookware suppliers. They are reasonably priced, easy to use and small enough for the smallest kitchen. Their design also makes them an attractive addition to the decor.
How does a vacuum coffee maker work?
The secret of this gadget is steam pressure and gravity. A vacuum coffee maker is comprised of two transparent bowls of equal size. The bottom chamber has a handle and pouring spout, while the top vessel has a siphon in the base that acts as a filter. It fits snugly in the neck of the bottom bowl. They are held next to each other in a frame. You pour hot water into the bottom globe, spoon the ground coffee into the top part, then stand the coffee maker on a heat source: a kitchen hotplate or a burner attached to the gadget itself. As the water reheats towards boiling point, steam pressure forces it up through the siphon into the top chamber where it meets the coffee grounds and starts to brew. Once all the water is forced up and the ground coffee beans are saturated, you remove the machine from the heat and as it cools gravity and lower pressure take over (the vacuum effect), the drink trickling back into the bottom bowl, ready to be poured.
Nowadays, you can find vacuum coffee makers made with high-quality borosilicate glass, stainless steel or heat resistant plastic, so you can find a style to suit your preferences.
What are the advantages of vacuum coffee?
To many coffee drinkers, using a siphon coffee machine is the perfect way to brew coffee since it puts you in close control of the entire process. You can monitor the water pressure, decide how fast or slow you heat it, how much coffee you add and how long you let the drink steep. The vacuum effect means nothing escapes - none of the flavour or aroma. So what you get is a richer, stronger drink than other brewing methods: smoother and cleaner. The water doesn't boil, which could impair the flavour, and the beans don't have to be finely ground. A fairly coarse grind size and quality works very well. Plus, no paper, man-made or cloth filter is used in the chamber, just ground coffee and hot water.
An important part of the appeal of a vacuum coffee maker is the choice of designs. Some of them look like a contraption that might belong in a chemistry lab, which gives just the right scientific appearance to the kit. This is ideal if you want to concentrate on the technical precision that goes into making the perfect coffee, or if you want an impressive gift for a coffee geek! Others are more designer chic, performing the same function while having a style that makes them a nice showpiece in the kitchen or at the dining table. They all have a capacity of five or six cups, so they can be the piece de resistance after dinner when you want to show off to your guests.
It takes time and patience to master the technique to use a vacuum coffee maker. If you watch coffee being brewed by an expert using a siphon, you will quickly see how theatrical the process and brew method can be; it is all about preparation and performance.
Vacuum/Siphon Coffee Essential Tools
An independent heat source is required when preparing coffee through the vacuum/siphon method, which can be a small butane burner, an alcohol burner or a halogen lamp; in Japan and in certain specialist coffee shops, a halogen lamp is the preferred heat source.
Most vacuum pots use a cloth filter wrapped around a metal disc to filter the coffee after it has brewed and is flowing back into the lower chamber. Be sure to thoroughly clean the cloth after every use to avoid any unwanted flavours or bitter notes making its way into your next coffees. While there are alternatives to cloth filters, such as paper or metal, these are not usually used with vacuum pots.
How to Use the Vacuum Pot Method
- 1. Prepare your ground coffee. Measurements are of course down to personal tastes, but a good rule to start with is 75g/l.
- 2. Boil a kettle of fresh water. You will ideally use water that has a low mineral content.
- 3. Place the filter in the upper chamber and ensure it is completely flush.
- 4. Add the boiled water to the lower chamber and transfer this chamber to your heat source. Recommended heat sources include a small butane burner, an alcohol burner or a halogen lamp.
- 5. Place the upper chamber on top of the lower chamber, but do not seal it just yet (if the chambers are sealed to soon, expanding gases will push water up into the top chamber before it is at the right temperature, resulting in an unpleasant tasting drink.
- 6. When the water begins to boil in the lower chamber, seal both of the chambers together and, if possible, reduce your heat source at this point. Boiling water should now begin pushing up into the top chamber.
- 7. The bubbling in the top chamber will start out quite aggressive, with larger bubbles forming, but this will gradually change to a lighter boil and once the bubbles have become smaller you are ready to brew.
- 8. Add your ground coffee to the top chamber and stir it completely in, then start a timer.
- 9. A crust will form at the top of the water and coffee mixture. After around thirty seconds, gently stir the mixture again to gather in floating coffee back into the brew.
- 10. After another thirty seconds, you can turn off the heat source. Shortly after, the coffee will begin to be drawn down into the lower chamber via the vacuum that has been created.
- 11. Allow the coffee to draw down completely, until a slightly domed bed of coffee grounds remains in the top chamber.
- 12. Transport the coffee into a separate coffee pot and allow to cool before enjoying your vacuum-brewed cup of coffee.
At Coffee Direct, all our coffee is roasted to order, and packed in one-way valve, foil fresh bags, so you can be assured that it will arrive in the best possible quality, perfect for your vacuum!
The best things come to those who wait
The pure pleasure of drinking coffee from a vacuum/siphon maker can be enhanced by the sheer enjoyment of the process itself. It takes time to prepare the equipment: setting up the chambers and siphon rig, pre-heating the water before pouring it into the bowl; gradually adding heat so that it is ALMOST boiling but not too hot for the coffee grounds, watching the ground coffee becoming saturated, checking the temperature then relishing the drip-drip-drip as your drink cools and runs into the pouring jug. Then, savouring the aroma as your fresh-brewed drink meets the air. The whole process takes a few minutes, and the process should last for about five minutes more to get the best flavoured coffee. If you're looking for a quick cup of coffee, this is not the way to go, but if you aspire to be a perfectionist and real barista, this might be right up your street.
Which coffees are best for vacuum makers?
There is no restriction to the type of coffee you can use in a vacuum coffee maker, but if you are investing in such sophisticated equipment, you want to get the best results, so it makes sense to start with top-quality ingredients. A vacuum coffee maker will give your drink a more pronounced flavour, smoothness and intense aroma. Look for beans that are strong in these areas. You may want something creamy and chocolatey, or your taste buds may prefer more fruity, citrus or nutty flavours. While you master the art of siphon brewing, you can experiment with different coffees or blends. At Coffee-Direct.co.uk, we have a wide range to choose from.
Here is our quintet of beans that are best-sellers for fans of vacuum coffee makers.
- Kenya Blue Mountain Coffee: Grown from seeds that originated in Jamaica, this produces a coffee with the natural sweetness of Blue Mountain Jamaica, amplified by the aromatic flavours and intensity typical of Kenyan coffee. Kenya's acidic soils provide optimum conditions for the growth of coffee, especially the renowned Arabica bean, and deliver fantastic cocoa notes when brewed. Kenya Blue Mountain is full-bodied, with a good acidity, hints of nut and citrus and a lovely caramel aftertaste.
- Kenyan Peaberry Coffee beans from Coffee Direct are sourced from the coffee cherries in the Nyeri highlands. Grown in a well-drained and loamy soil at high altitude, roasting peaberry coffee beans from this region gives you a rich, earthy and fruity flavour with an aroma all of its own. The taste is strong and slightly tangy, offering a full body and delicious flavours of cocoa.
- Kenya AA Coffee may be just what you want if your taste is for something smooth and mellow, without bitterness. Kenyan coffees are known for their deliciously sweet, berry fruit flavours and intense acidity, and any with an AA rating are specially selected larger beans that are considered superior and therefore more valuable.
- Ethiopian Yirgacheffe is a very smooth, great-tasting coffee. It has a really distinctive fruit-like acidity that adds a pungent addition to Ethiopia's coffees' traditional mocha flavour characteristics. Grown in the Sidamo province, this is one of the best-washed coffees: this process sees the cherry of the bean removed before the bean itself is dried, in advance of roasting. During washing, any unripe cherries float and are removed, while the ripe ones will sink, and only these are used. This guarantees the best quality.
- Our Jamaican Blue Mountain Coffee is roasted expertly in small batches, which produces a superior and sophisticated flavour, at the same time lacking any bitterness and giving you that sweet and creamy aftertaste that is synonymous with Jamaican coffees. Year after year, Jamaican Blue Mountain tops lists as the most luxuriant and delicious coffee in the world - consequently one of the most expensive.
At Coffee Direct, all our coffee is roasted to order, and packed in one-way valve, foil fresh bags, so you can be assured that it will arrive in the best possible quality, perfect for your vacuum!