Interview: Alan Adler Answers Your Questions About Coffee and Throwing Objects

A while ago you had the chance to ask inventor Alan Adler about making the perfect cup of coffee and throwing things really far. Below you'll find his best coffee brewing tips and the answers to those questions.

How did you get interested in making thrown toys and brewing coffee?
by samzenpus

The two things that you're known best for are the Aerobie toys and the AeroPress. Were these things that always interested you or did you stumble into engineering them.

Adler: In the case of the Pro Ring, it was a deliberate effort to try to design a flying disc that was better aerodynamically. Better in the sense of lower drag, because lower drag would mean that you could throw it farther and also easier. For the coffee maker, again, it was a deliberate effort. I got to thinking that the way I made coffee did not make a good single cup of coffee. I and a lot of other people I know seem to want to just make a cup of coffee as opposed to a whole carafe full. Most people, including me, use an automatic drip machine, and when I tried various recipes to make one cup of coffee that way, it didn't work very well.

I started experimenting with various methods. I began mostly using a pour over on top of a mug, and experimenting with temperature and amount of coffee. I found there was a big improvement in taste quality when I lowered the temperature, but I was troubled by the fact that pour over was taking about four or five minutes to run through. I had read that the longer you drag out the coffee brewing process, the more bitter the taste of the brew.

I got the idea of making a cylindrical chamber where I could apply air pressure and push the liquid through rapidly. I made a prototype in my shop in early February of 2004. The very first prototype tasted better than anything I had ever made with a cone filter. So I knew I was on track and I really spent all of 2004 perfecting the design, experimenting with various types of seals, and various diameters and lengths, and spent nearly a year getting production [tooling] made so that we could go into production.



Aerobie Drones?
by CanHasDIY

After reading the article about the Aerobie setting a world record as the farthest flying thrown object in human history (uber-neat, BTW), I wondered: Do you think there's any way that such a design would work as a small drone platform? Perhaps something that can be thrown from the hand, then perpetuate flight at least semi-autonomously?

Adler: I haven't come up with anything that is practical. Every idea I considered, I think is really inferior to a relatively conventional airplane, a configuration that's not rotating.



The Physics of the Aerobie
by MonkeyDancer

The Aerobie Pro Ring is one of the best skill toy inventions ever created.Can you tell us about the physics and engineering challenges that you had to overcome to break the world record?

Adler: I spent about eight years on the project. Not all of those eight years were with rings. I wasted quite a few years trying to make a better disc.

The ring is really a superior shape. It's better than a disc, and it's better because it flies and behaves sort of like two thin airfoils one after another. The front half of the ring is behaving like a leading air foil and the rear half of the ring is behaving like another airfoil. A very efficient airplane, like a glider, has long thin wings opposed to short fat wings. And by going to the shape, we have something that's like two long thin wings.

The front half of the ring naturally wants to develop greater lift, because it's flying in undisturbed air. When an airfoil develops lift, the process of doing that forces air behind it downward a bit. For every action there has to be a reaction, and in this case, the reaction pushes that air downward, so the rear half of the ring is at a disadvantage. It's flying in air that has been pushed downward a little bit by the front half. A ring or a disc or anything that's spinning, won't fly straight unless the lift is balanced evenly between the front and the rear. The challenge was to figure out how to do that, and I had a partial success in 1980 when I developed a ring that I licensed to Parker Brothers called a Skyro. The Skyro was a little bit like an Aerobie, but it didn't have that little rim around the outer perimeter. it was so efficient that it set a new record for a human thrown object. It first set a record of 750 feet and in less than a year later, upped that record to 850.

During that time, I met Mr. Norris McWhirter, the co-editor of the Guinness Book, and he was quite fascinated by the records that we set throwing that device. However, it was really only stable at one air speed, and I had developed equations that told me if I could make an airflow that satisfied certain equations, I could make a ring that was stable over a wider range of airspeeds. By stable, I mean it would fly straight, whether it was flying fast or slow. I had a breakthrough in January of 1984 when I came up with that little rim around the outer perimeter. I call it a spoiler lift.



Will Aerobee do a Milk Steamer as well?
by billstewart

I'm guessing the answer is probably no, because it's not something that's easy to do in plastic, and in a hotel room you can get by with heating the milk in a microwave, while there are other devices out there for stove tops or camping stoves. But I'd love to see one if there's a practical way to do it.

Adler: No. What could we contribute over and above an already manufactured milk steaming machine? There are some really nice kettles on the market that allow people to dial whatever temperature they want as opposed to just boiling water. When we first started, there were only a couple on the market, but now there are probably a dozen different kettles, and they're useful not only for the AeroPress but also for brewing tea.



Metal filter for Aeropress
by hawkinspeter

I've been using a metal filter with my Aeropress(es) for a few years now and was wondering if you're ever going to sell a version with a permanent filter? Also, how about a redesign to make the upside-down method a bit easier? (The upside-down method allows for better control over the steep time).

Adler: I had a bunch of metal filters fabricated by the photo-etching process which is a sort of a relative of the way silicon chips are made. The process allows you to make very, very fine holes, but they never tasted as good as paper filtering.

Along the way, I discovered that coffee that's made with metal filters, or maybe we should say coffee that is not made with a paper filter, contains two harmful oils, called cafestol and kahweol. They've been discovered to be the most powerful blood cholesterol raising substances ever found. So the people who drink coffee that's made with a metal filter typically have LDL cholesterol, which is about ten percent higher than people who drink paper filter coffee.

So I decided that even though some people said that they wanted a metal filter AeroPress, I couldn't with a good conscience produce it. However, there are a number of filters on the market from other manufacturers now. I asked the guy who runs The World Aeropress Championships if they were permitting metal filters in Aeropress competitions, which are judged solely on taste, and he said, yes, we allow them, but no metal filter brew has ever won a single heat.



Re:Glass or steel Aeropress?
by Anonymous Coward

Was the Aeropress world championships something started by the company and what is the best recipe to come out of it?

Adler: It has been going on for about five years, and it was the invention of Tim Wendelboe who runs a cafe in Oslo, Norway. He's also the Norwegian importer for the AeroPress, and he held the first two championships in Oslo. Tim Varney worked for him, and sort of took it over, and then they decided to start moving it around to different countries, regions, and cities.

These championships just sort of sprang out of the grass roots all over the place. We have tried to step back from it and tried to be supportive in the sense that we often make trophies, but we don't tell them how to run it. I'm very happy with the way they run it. They judge it on taste, and I think that's the way it should be judged.

Now as far as recipes go. I think if you look at the winning recipes, over the years, they approximate what we tell people to do in our instruction booklet. We suggest people brew right side up with 175 degree water. Most of the winners have been in that ballpark. Occasionally, somebody will win with a variation on that, but I think it's fair that most people win with something that's pretty close to the normal process.



What's AeroNext?
by timothy

Both the Aerobie and the AeroPress embody design traits I really like: they're durable, have few pieces, and work simply by dint of ordinary (vs. extraordinary) human-muscle power. Basically, they remind me of simple machines. (As in the wedge, the lever, etc.) What are your favorite likely areas for further improvement?

Will you come up with good improvements on ...
- Flashlights? (Muscle-powered flashlights have gotten much better, thanks to LEDs, but they still mostly suck.)
- Sailboats or kayaks? (What could modern materials and thinking bring to small person-powered / wind-powered watercraft?)
- On that front, paddles / oars ... wrt ergonomics and efficiency, I think there is a long way to go ...
- Whistles? (Pealess whistles have come a long way, but progress isn't over)
- Waterguns? (Where is the next SuperSoaker-style leap?)
- Bicyle fairings? (A semi-standardized clear fairing would be useful for lots of people, esp. as some big U.S. cities improve their cycling infrastructure.)
- Juicers? (A human powered AeroJuicer sounds like a good idea to me ...)

Not to say that for any of the above items that there aren't smart people working in the field ... but Hey, there were lots of coffee makers and coffee making methods before the Aeropress, too.

p.s. What about smaller and bigger AeroPresses, for light travel and for bigger gatherings? :)

Adler: I haven't worked in any of those areas.

With regards to a small model, I think that the savings wouldn't justify the investment because the existing one is pretty small.

With regard to a bigger model, I've experimented with it at length, and perhaps someday I will bring one out. I feel that the present AeroPress really meets 80% of the average person's brewing needs. Because it is capable of brewing three or four cups if you want to. We get a lot of letters from people who say that they brew a few cups and then maybe three or four hours later in the day, they do it again, and before the AeroPress, they were brewing, let's say six cups in a drip machine. Towards the end of that six cups, it tasted awfully stale.



Perfect Coffee
by samzenpus

There are almost as many different ideas about how to make a cup of coffee as there are coffee drinkers. What advice would you give someone trying to make a perfect cup?

Adler: We get a lot of resistance on two fronts relative to the AeroPress. There are people who buy AeroPresses who use it differently, and the first way they use it differently is they don't use 175 degree water. They say, oh you can't possibly brew coffee at 175 degrees. My answer always is, well, you can use any temperature your heart desires, but you owe it to yourself to try 175, because whenever we do blind tasting, whether it be for just average people or professional coffee tasters, they invariably choose 175. I would say that the average person who had an AeroPress, has never tried 175, even once. They go hotter, and you get answers like 'I don't use boiling water. I boil it, and then I wait a minute before I brew.' Well, with the average kettle, if you wait a minute, the temperature goes from 212 to 210. It takes 17 minutes for the average size kettle to go down from boiling to 175.

You're really missing out on a wonderful tasting coffee if you don't at least try a lower temperature. I have never found a single person, who when given a test between 175 and higher temperatures, has chosen the higher temperatures.

I gave a talk at Google about a year ago, where I said that there are a lot of people who would rather jump off of the Golden Gate Bridge than to dilute their coffee, and that created a good laugh. But we tell people to brew their concentrate, according to our instructions. At that point they are brewing something as strong as espresso and then, if they want a cup of American coffee, to add water to it.

The idea of pouring water into the brewed concentrate makes peoples shiver in fear. They think somehow that they are going to wreck it, and so they do things like, push water through the same bed of grounds. A typical user will put in a scoop of coffee and then fill the AeroPress with water to the very top and push it through as opposed to what we say, which is just fill to the number one, and push that through, and then add water afterward.

It's a little like the temperature thing, most people have never tried that, and it tastes better. The reason it tastes better is you're not forcing a lot of water through the same grounds and extracting more bitterness. So once again, I tell people you can make it anyway your heart desires, but at least try the way we recommend, because I think you'll like what you taste.