Challenge of High Altitude Brewing

Question

Hello Dr. Brew! My name's Austin and I run a coffee shop/brewery in Silverton, CO. One of the customer service reps gave me your email in hopes you could help me with some questions about my old (but new to me) Bunn Dual.


I must preference we're above 9000 ft and we had to tinker quite a bit with our single head fetco to brew good coffee at this elevation. The lesson we learned from our old brewer is that we needed longer brew times and more coffee to compensate for the fact that water boils at 187 at our altitude and we're unable to reach a proper extraction temperature. We've been using 4oz coffee for .5gal, 7oz for 1 gallon, and so far haven't been brewing 1.5gal batches.

Our Bunn machine so far doesn't seem to be giving us the full flavor coffee we're used to. The Bunn Dual in question is an older model, so as far as I know, we are only able to change the thermostat temperature and the 6 knobs for time of brewing .5gal/1gal/1.5gal for each head. We don't have the set/lock switch to adjust the 2 second duration of the brew. It seems that the longer we set the brew, the more water we have in the final pot, i.e. the .5gal setting at 3 mins brews .5gal, the .5gal setting at 5 mins brews .75 gal. The very kind rep is sending me some of the 6 hole nozzles with smaller diameter holes to help limit the flow of water. I've also shut off the water bypass, since that didn't seem like it would help.

Any help at all would be appreciated. Are we on the right track? Do you have any other questions for me? Can you think of anything else we could be doing to achieve a fuller flavor coffee at our elevation?

Thanks in advance!
Austin L.

Answer
Austin,
Brewing at high altitude is a challenge.  The temperature of 186°F to 188°F would be the top range for 9,000 to 10,000 feet.  From your description the Dual you have is an older model without any capability of setting a pulse sequence to lengthen the brew water delivery time.  The spray heads with fewer and smaller holes will do that, although the pattern and uniformity of saturation may suffer.  Appears the weight of coffee has been increased to compensate for loss of temperature.  You may also want to grind as fine as you can to expose additional surface area (but not so fine you create an overflow issue).

Happy Brewing,
Dr. Brew

Hot or Cold

Question

Dear Dr. Brew,
I am going to buy the CWTF15 brewing system. Finances are at a minimum and I hope that my coffee shop picks up over time. What I would really like to know is, can I bring the hot water into the brewing system? I noticed that it will take time to get the brew system back up to temperature after the first cycle. If I bring in hot water, would this not reduce the recovery time?
Thanks for the help in this matter.
Douglas

Answer

Simple answer is no. Cold fresh water supply should always be used for beverage preparation.

The components in the water delivery system of the brewer are not designed for heated water.

Happy Brewing,
Dr. Brew

Brew Ratio ( Water / Coffee)

Question

Hi Dr. Brew,I bought a new Bunn STX coffee maker. What is the ratio of coffee to a 5 oz. cup of water? I typically use a normal plastic coffee scoop.

Thanks,Tom




Answer

Tom,
Scoops vary by manufacture, although the majority of scoops I have tested hold approximately 7.0 grams (about 0.25 ounce(s)). I would suggest one level scoop per 5 ounce serving as a starting point, then adjust up or down for your favorite cup.

Happy Brewing,
Dr. Brew

Half-Time

Question


Hi Dr. Brew, 

I have a Bunn VPR commercial brewer, and I have watched the videos you have posted on You-tube regarding brew times and ratios. I was wondering, what technique I could use if I only wanted to brew half a pot on such a machine? Particularly, if I add enough grounds for half a pot and pour only half a pot of water into the machine, the ratio would be correct but the brew time will be half the optimal time for a complete brew as the water still flows out at the same rate.



Answer

Brewing a lesser volume than full always has compromises. You did not mention if you are grinding on demand or using pre-ground coffee. If grinding on demand you have the option to grind slightly finer to compensate for the faster brew time. When using a pre-ground coffee a slightly higher dose weight will for the half brew may satisfy your taste in the final cup..

Remember it's all about the cup and making a brew you like. Experiment!

Happy Brewing,
Dr. Brew

Dr. Brew Mini-Series: Roast & Grind

As kids across the country are starting a fresh new semester in school; it is time for us to conclude our educational video mini-series Better Brewing with Dr. Brew too.  Over the past few months, Dr. Brew has provided educational videos explaining: 

• The importance for quality water when brewing coffee or tea
• Why allowing a brew cycle come to completion is important  for great coffee
• The difference in filtration methods

The last educational lesson in the series will discuss coffee roasts and grind size. You are only one video away from flipping your tassel towards a better brew education. 


Do you enjoy a light roast coffee?  Or is a dark roast more your style?  Are you confused as what really is the difference in coffee roast profiles?  To understand coffee roast you first need to know a little about roasting.  Roasting is a process that green coffee beans go through to bring the oil to the surface of the bean and unlock different flavor nuances.   As Dr. Brew explains in the video, roasting coffee beans can do a couple of different things;  it can roast flavors in by roasting the coffees darker to caramelize more sugars; or it can roast flavors out by roasting a coffee bean lighter.   Roast masters use the roasting process to create different flavor profiles.   


To help illustrate how coffee roasts differ Dr. Brew compares the different roasts to the different steak preferences.   A light roast coffee is comparable to a medium rare steak, where it is lightly roasted on the outside.  A dark roast coffee is comparable to a well done steak where it charred on the exterior.   


So what are the overall flavor profiles in these different roasts?  While roast color does have an effect on the flavor of the coffee it is not the only determining factor.  Origin of the coffee bean can make a difference in flavor as well. Therefore, a light roast coffee from Ethiopia is going to taste different than a light roast coffee from Guatemala.  However, as general rule of thumb when it comes to roast and taste:

• Light Roast coffees are going to be milder in flavor
• Medium roasts have a more intense flavor over light roasts coffees due to more caramelizing  of  the sugars
• Dark Roasts coffees have deeper caramelized   sugars in the coffee beans and a smoky flavor. 

The type of roast you select to brew and enjoy is based on personal preference, and the formula for brewing great coffee does not change based on your selection.  You do not need to use more coffee just because you are brewing a light roast, or fewer grounds when brewing a dark roast. Your roast selection should not affect how much coffee you use when brewing a pot.    As Dr.  Brew explains you wouldn't use half the amount of ingredients when making a chocolate cake, just because it is darker than a vanilla cake.  The same is true for roasts of coffees.  The formula for the amount of coffee you use remains the same regardless of the roast as long as you are using the correct grind. 


So how should you grind the different roasts of coffee?  Coffee should be ground based on the speed of the brewer, not based on the roast of the coffee.  Brewers that brew in less than 4 minutes should be ideally using a fine grind.  A fine grind will have a texture similar to table salt.    A drip grind should be used in brewers that take between 4-6 minutes to brew.   A drip grind, or medium grind, has a texture similar to coarse black pepper. Brewers that take longer than 8 minutes to brew should be using a coarse grind.  French press and plunge method often use a coarse grind to reduce the amount of coffee fines coming through the beverage.   *Note: Darker roast coffees can produce fine grinds.  To help combat this adjust your grind setting a little coarser to achieve the right grind size for your brewer.  

To learn more about coffee roast and grind watch the fourth and last video in the Better Brewing with Dr. Brew series shown below.