The Texas Coffee School Vacuum Siphon Brewing How-To Guide | Coffee Education | Barista School

The Texas Coffee School Guide to Brewing Coffee With a Vacuum Siphon Pot – Also Known as a "Vacpot"

Below you will learn the science, technique and best practices essential to making outstanding coffee using a vacuum siphon pot. If you want to learn more about coffee extraction and gain an in-depth understanding of every primary coffee brewing method, check out our Coffee Education Program for a complete list of upcoming coffee classes and barista training workshops.

WHAT YOU WILL NEED

• Hot water (195 to 205 Degrees F)
•A high-quality burr grinder
• A Vacuum Siphon Coffee Pot (Stovetop or Tabletop)

• A butane burner (if you have tabletop version)

• Cloth vacpot Filters (Only if your pot didn't come with any)
• A digital kitchen scale to weigh out correct amount of coffee
• A digital timer

• Either a spoon, spatula or whisk for stirring

(Optional) An electric water boiling kettle. (This is the best one for the money!)

THE VACUUM SIPHON POT
A vacuum siphon coffee pot works on the principle of expansion and contraction of gases - specifically, water vapor. Water vapor is what allows the device to brew a full infusion style of coffee and filter the grounds efficiently, leaving a generally clean, pristine cup.

Siphon coffee pots are made up of four parts: the bottom container where the water initially sits and the brewed coffee eventually rests; a top container that has a siphon tube attached to it, where the coffee brewing takes place; a type of sealing material (usually a rubber gasket) to help create a partial vacuum in the lower chamber while brewing is taking place, and a filter, which can be made of glass, paper, metal, or cloth.

There is also a heating source, and there's usually three types – a cloth-wick alcohol burner (slowest), gas or electric stovetop (faster), or a specialty butane burner (fastest). There are additional heating devices, including the halogen burner system which are best for achieving more precise temperatures and best tasting results.

BREWING PARAMETERS

Coffee-to-Water Ratio:

Vacpot: 1.6 - 2.0 grams of coffee per fluid ounce of water

If you don't have a scale, use 2 table spoons of coffee per 6 fluid ounces of water.

Grind Size:

Vacpot: Slightly finer than your drip setting. Similar to typical granulated table salt.

Brew Time:

Vacpot: With different sized vacpots (and different heating methods), different steep times are required. Because we're controlling the flame to a minimum for a "gentle" brew, we suggest steeping about 75 seconds to 2 minutes.

Brewing Water Temperature:

Vacpot: 195 - 205 Degrees F

STEPS FOR BREWING

1. Use the table above as a reference.

2. Install the filter by dropping it in the top vessel, and pulling the beaded metal cord down through the siphon tube and hooking it on the bottom. This keeps everything in place. Use a small amount of hot water to pre-wet the filter.

3. We recommend starting with water just off boil. If you start with cold water and assemble everything before heating, some water will creep up the siphon long before its temperature is optimal for good extraction.

4. Add freshly ground coffee in the top chamber and gently shake it to ensure the coffee bed is level. (TIP: For best results, grind just before brewing - not minutes before.)

5. Gently insert the siphon vessel portion into the bottom glass container, taking care to not knock the siphon (it can chip). Press to ensure a good seal with the rubber gasket.

6. Add your heat source. We use a small butane burner ($30-$50) which is very efficient and has a controllable flame, which is important for the brewing process. Right now, it should be running on high.

7. As the water starts moving up to the top chamber, start your timer. Wait a few moments and give the coffee a few stirs to fully saturate the grounds. At this point you also want to lower the flame a bit.

8. Once 3/4 of the water has reached the upper chamber, further reduce the flame on the burner. The idea is to have just enough flame to keep the water up top, continuing the production of steam or vapor "bubbles" that will flow up the siphon tube and pass through the brewing coffee. Remember, we don't want the top boiling - just brewing.

9. With different sized vacpots (and different heating methods), different steep times are required. Because we're controlling the flame to a minimum for a "gentle" brew, we're steeping this about 75 seconds to 2 minutes. (we are using 40g coffee and 20oz water)

10. After proper steeping time has elapsed, completely remove the heat source (don't just turn it off) to start the kick down phase. We recommend removing it completely so there's no residual heat coming up from the burner to slow down the kick down.

11. Kick down begins. As the vapor gas in the bottom vessel starts to contract, shrink, and change back to water, it creates a partial vacuum of negative pressure, and pulls the brewed coffee through the filter back to the bottom vessel.

12. At the end of the kick down, air is sucked very rapidly through the spent coffee grounds to fill the vacuum in the bottom container, resulting in bubbling and turbulence. This is the indicator that your brew is done.

13. At this point, you can carefully remove the siphon vessel portion of the vacpot, placing it in the lid/built-in stand. Serve, and enjoy.

GOOD PRACTICES

Adjust parameters to compensate for individual coffee characteristics.

Small changes in technique can result in big flavor changes, so be sure to use consistent heating, timing, and stirring techniques.

As a general rule, darker roasts work well with cooler water and lighter roasts with hotter water.

Too long of a brew time can lead to over extraction; too short can lead to under extraction. Use time as a tool to fine tune a brew.

If coffee is too bitter, coarsen the grind to help ease the extraction. Adapting the coffee to water ratio may then be necessary to balance the concentration.

The parameters work in tandem so it is a good idea to allow for experimentation with each to truly master brews.

Water Quality – Use clean water free of any off tastes or odors. Water quality differs from region to region, so a water quality test should be taken to discern the appropriate treatment required. If you are home brewing, a Brita pitcher will work just fine. Do NOT use bottled water. It tends to be "too filtered" and there are not enough TDS in the water for "the good coffee flavors to attach to". If this water is used the coffee can taste quite bitter and undesirable.

Keep your vacpot clean by thoroughly rinsing after each use and occasionally using a cleaner recommended for coffee pots. We recommend Urnex Tabz or other applicable Urnex products.

CONTINUING EDUCATION

Texas Coffee School offers a variety of coffee and barista training classes that can enhance your coffee knowledge and brewing skills. CLICK HERE for classes and enrollment details.

Texas Coffee School
Through our coffee education program we aim to cultivate quality-oriented “coffee people" that share in our passion for exceptional coffee and the craft of making it. We offer individual barista training classes for the casual home enthusiast all the way up to professional multi-day barista training and coffee business workshops for those looking to open a coffee business. Click on any class below for more information.