myShoggoth

Home Roasting Coffee

Roasting your own coffee is one of those unique activities that makes it possible to optimize for both cost and quality.

Green Coffee Beans

The coffee bean is the dried seed of the fruit of the coffee tree, and because it is dried it has a long shelf life.  If you store green (unroasted) coffee beans correctly, they can last a year or two with only slow taste degradation.  I've kept some for four or more years and the results are still drinkable but very bland.  For the cost conscious, you can buy in bulk and store for a long time.

My rule of thumb is you can expect to pay half the price of roasted coffee for green beans as starting point, and it goes down from there.  An example of prices (for illustrative purposes only) might be:  one pound at $4.50/lbs., two pounds at $4.25/lbs., five pounds at $4.00/lbs., twenty pounds at $3.50/lbs.  I would expect the same coffee, roasted, to be for sale at $8-$9/lbs. or more, and you don't have as much control over quality (over the specific beans, roast level, and freshness).

Roasting

Roasting coffee is similar to popping popcorn; you heat the beans to high temperatures and the bean goes through big changes including expanding in size, which causes them to pop loudly.  You're cooking the beans, and many of the same principles and concepts apply from other styles of cooking:

1. There are a number of different ways of getting the heat to the beans, and each imparts a different type of taste.
2. Thermal inertia is very important, once the beans are heated to the temperature you want them it is critical to cool them down quickly.
3. Oxygen is the enemy, causing staleness.  Store roasted beans in an airtight container.
4. For optimum flavor you should "rest" the beans after roasting for a while, how long depends on the beans themselves and can vary from 12 to 48 hours by variety.

Rather than duplicate all the information about the different methods for roasting, I'll just give a pointer to my favorite source and his instructions on home roasting methods and devices.  The number of specialized small appliances for home roasting coffee beans has been steadily getting larger, and they have been getting better over time.  You can go from roasting beans in your oven or in a wok all the way to a specialty device where you put the beans in, dial a setting, and hit a button.

The next step up is small commercial roasters, which can handle one to four or five pounds of coffee and generally cost thousands of dollars.  Many are meant for large commercial outfits that want to try samples of the beans they're considering buying in bulk (and are thus called "Sample Roasters"), but more recently a niche has been found for small coffee shops and espresso stands that want to roast their own in small batches for cost savings and product differentiation.  High end home roasters have been known to buy them, but it is pretty rare due to both cost and batch size.

I have one big warning: Roasting coffee produces smoke, especially if you want to experiment with the darker roasts.  I used to roast over a vent in the kitchen, but now I strictly do it in the garage.  It only took a few mishaps and smoke filled house incidents before I was learned my lesson.  Once the batch size gets above 3 oz. or so, having a venting system to get all that smoke outside is important.

Brewing the Best Coffee

I'm not the worst that I know, but I'm definitely a Coffee Geek (but not the Coffee Geek).

I buy my coffee green, roast it myself, and am very particular about how it is brewed.  That said, I'm not a total snob, I will drink coffee from Starbucks, some restaurants, some cafes, etc.  It just takes special circumstances, since the stuff I make myself is generally leaps ahead of any of the above.

I started a 'coffee club' at work, and besides supplying the beans and the brewer I occasionally will give people info on how to make better coffee and other tips.  Since I have this forum that has no particular purpose anyway I might as well put some of them down.

Grind Late

For those who are buying specialty coffee instead of instant the first mistake is often to get it ground at the store.  When you open a bag of ground coffee you know that wonderful smell that comes out that makes you think, "this is going to taste soooooo good"?  When you grind the beans, it takes all the compounds in the coffee that make it taste and smell so good and releases them.  They don't last long.  When you open the bag the compounds that are already free have just escaped forever (they weren't in the beans anymore), and that wonderful smell was them waving goodbye to you on the way out.

A very general rule of thumb is green coffee beans can last for years (1-2 is probably the longest they should be kept, but I've done longer and they just start getting flat), roasted coffee can last for weeks (more than two and you better have it vacuum sealed, even then four is really pushing it and you're probably drinking stale beans), and ground coffee can last maybe an hour, tops.  Past these times, the perishable good you are partaking is... well... not so fresh.

A couple things I have to add here: Don't buy flavored coffees.  Flavoring coffee is fine, there are plenty of ways to do it after you've made the coffee, but don't buy the pre-flavored beans.  Chemicals are added which can gum up your grinder and make it nasty.  Second, be careful about how you grind.  Burr grinders are better, but the whirly-whacker ones can be used as long as you're careful not to let the grounds get heated and start cooking.

Buy Early

The fresher the beans you buy the longer they will last and, except for a few points I'll address in a moment, the better it will taste.  You'll notice how very few coffee roasters date their coffees, by either crop year or roast date.  If you find one they will be worth further investigation, since it is likely they care deeply about quality and take pride in their craft.

You want the beans in contact with as little oxygen as possible, that's what makes them go stale.  Additionally, the beans will give off a lot of carbon dioxide for a few days after roasting, and it is best if it can be kept away.  Foil valve bags have been developed specifically to allow you to vacuum out the air, seal it, and allow the carbon dioxide to vent.  This is ideal, and roasted coffee will stay fresher for longer this way than any other.

You might think that the best time to brew a coffee would then be immediately after it was roasted, but this turns out not to be the case.  As the beans exhaust carbon dioxide and recover from being cooked, their flavors change and develop for a while.  The process is conceptually similar to letting a roast rest after cooking, and in fact letting it sit is also called 'resting'.  It varies greatly by origin, crop, and roast, but a good guess would be 24 - 48 hours is the peak for flavor.  I've had at least one coffee that was incredible at its peak, but otherwise just kinda 'eh'.  There's an idea, maybe a Brigadoon Blend.

Yet another good reason to know when the beans you bought were roasted.

Drink Quality

This may seem obvious, but it is very difficult in practice.  Coffee is a crop, which means that variations from year to year make regions, brands, and even individual farms taste different with each crop.  If you really loved the coffee from a particular farm in their 2002 crop, you may find the 2003 crop to be even better, or much worse.  No way to tell until you taste.  Even worse, you can have the same coffee from the same farm harvested at different times of the same season and get very different results.

How do the big coffee producers get around this problem?  Blending.  They buy from a lot of different places all the time, roast the beans, and mix them to produce a taste profile that is consistent from year to year.  Because of the variations in the crop the contents of the blend will vary as they adjust to get back to the taste they are looking for.

Another technique is to roast darker.   With lighter roasts, the individual flavors of the beans are more vivid (for better or worse), but as the roasts darken the taste of the roast level itself becomes stronger and that of the beans weaker.  By roasting darker coffee producers can achieve a more consistent taste.  This is one of the reasons that Starbucks coffees tend to all taste the same, even when they're from different origins.

I buy my coffee beans (usually green, but he does offer a limited amount of roasted coffee) from Tom at Sweet Maria's.  He does blind taste testing of coffees and only caries the ones that meet with his high standards, I've never bought anything from him I didn't like.  I give the same advice to others that I took myself six years ago or so; find a shop, roaster, or someone else whose taste you agree with and trust, ask questions and let them know what you like and don't like.  They'll be able to help you better, and you'll get a better idea of what you like and don't like.

Brew Well

All of the above is for naught if you don't have a brewer that can deliver the goods.  The important factors are temperature, time, and water quality.  The water needs to be high quality but not distilled, it needs to be close to but not at or above boiling, and it can't hang around in the grounds too long.

• If your water temperature is too low, the water is distilled, or it moves through the grounds too fast, you won't extract all the great flavors and you should expect a flat, bland cup.
• If the temperature is too high or the water moves through the grounds too slow you will over-extract and get a lot of the bitter and nasty flavors from the coffee.
• If the water quality is low, you'll have a bunch of tastes that will interfere with the coffee, never in a good way.

My personal favorite way to brew is the one I use at home, the Cona Vacuum Brewer.  No filter (which can add a papery taste to coffee), the temperature is self-regulating, and it just plain looks cool.  At work I have a brewer more suitable for a small office, the Solis Master 5000 Digital.  Only had it a few months but we've already made over 1200 coffees with it (it keeps track).

Finally, don't let the brewed coffee sit on a burner and continue to cook.  Better to put it in a thermal insulated container and let it cool (slowly).