I am looking for a place to attach the water shock absorber. I have a couple of ideas now. I can connect the shock absorber right at the high pressure nozzle of the pump. It would give me an opportunity to connect a pressure gauge. That would force me to replace or modify the high pressure tube, which, to my surprise, is made out of heavy plastic. The plastic holds 15 bar pressure. Impressive! Another possibility is to attach it to the input of the OPV valve. It is a less attractive option because of the lack of space around that area.

The second option is an Allen screw that looks like a screw on the E61 head. It might be there for the same reason too. If it it the case, then I should be able to use it either for a water temperature gauge mod, or use it for the pressure gauge and shock absorber.

I also disassembled the shower head and discovered that it is a bit different. I think it is a simpler design than on the Silvia.It might be less efficient as well. I have not way test that. I do not have a SIlvia.

I am posting a few pictures of the Audrey head here.

Three-way Solenoid Valve

Three-way Solenoid Valve Label

Assembled Shower Head

The difference between the Silvia and Audrey is visible on the following picture. On the Silvia, the shower head has a removable disk below the shower screen. On the Audrey, the disk is not removable. The small black dot on the right of the deep part of the head is the water orifice.

Shower Head with the Screen Removed

Finally, a little bonus for phone junkies like me. I used the Audrey water container as a light modifier for taking the pictures above. I am using a Nikon SB 28 with a PocketWizard Plus II, You can see the flash at the top of the picture and the Wizard in the left bottom corner.

Audrey Light Modifier for Off-Camera Flash

JeepinGeo also posted a Youtube video of this setup (I assume it is the same guy and the same setup) in action.

The second way is to add a programmable timer to the pump electrical circuit. It is a bit more difficult because it requires a relay, power source, wiring, etc. It sounds funny too. On the flip side, it is still simpler than this one:

Just to understand the workings of E61 group head great guys on the web created a few drawings showing interal design.

…and even a thermal model of the E61 group head.

Where can you get the good beans? Buy expensive? It is a good rule of thumb with other things, but not for coffee. Often it is just the opposite. The more expensive a roast is, the less buyers can afford it. It leads to longer shelf time for the costlier roasts. Not good, isn’t it?

Well, may be one should buy a fresh batch from a local roaster? It might work, if you have a good roaster who knows what he/she is doing. How many coffee roasting places you know in 5 miles area around you? I am lucky and I have at least three. But the catch is that they run a business and roasting in small batches is not an option for them. How fast can they sell a large batch? Not too quickly. Within three days guaranteed? Are you kidding me? This is why you end up getting a mix of freshly roasted with some slightly stale beans.

The verdict is – if you want good coffee, you have to make it yourself. This is why I started to roast.

At first I used a roaster that I received as a gift. It was a “Fresh Roast II”, an early predecessor of this machine.

Mine did  not have a digital thermometer and it did not have any means of the temperature control. But it produced coffee so much better than anything I could buy (more by chance than by design, I should say) that I’ve gotten hooked on coffee roasting.

It did not take me long to become unsatisfied with the lack of roasting control in the Fresh Roast II. When it fell off my counter and shattered into pieces about eight months into my exploration of coffee roasting I did not try to replace it with the same type of device. This roaster takes a few ounces of green beens at once. One batch is hardly enough for two espressos! Total absence of temperature control make roasting too quick. Temperature grows so fast that a couple seconds difference in roasting time  make a big difference in the final result. My requirement for the next roaster in the range of  20-25 minutes roasting time and about a pound of beans per batch.

Well, I have a roaster like that now. It is a self-made DIY rig made out of a set of  things that are not expected to be found together. It all sits on a chassis of an Omega photo enlarger. A few years back this enlarger was a dream of many photo enthusiasts. Now, it is a staple of garage sales.  A modified bread maker, a heat gun, and a digital thermometer with a thermocouple provide all the heat and spinning action. The heat gun can move up and down of the enlarger’s shaft providing fine control of amount of heat applied to the beans. As beans grow in size, distance between the spout of the heat gun and the beans reduces. I move the gun up the shaft a couple of times during roasting. This the roast relatively constant heat flow. At about 350F I am moving it higher up again to slow down roasting between the first and the second pop.  The rig produces a pound of perfectly roasted coffee within 30 minutes.

The coffee roasting rig

The idea of using a bread maker and a heat gun is not mine. I found it on the Youtube. The coarsest version of it is called “a heat gun and a dog bawl”. I think my design is a Cadillac of the roasters of this type. The only think that I might add to it is a temperature controlled heat gun, but I am not sure if it would add anything to the roast quality. You can see a video of this rig in action in my other post.

Stay tuned for an DIY description of the rig! Let me know if you are interested to encourage me writing the post!

This is the product it produces

Roasted Beans

Once PID is installed the next big thing is to find optimal brewing temperature for your setup. I found my sweet spot at 98C. The PID keeps boiler just below boiling point three degrees above optimal brewing temperature of 95C. This tree degrees drop happens while water travels through the gropuhead and warms up the grinds and  the portafilter.

I found that it does matter if the grinds fall into the porafilter directly from the burrs of the grinder or from a container. Free falling grinds give much more even fill to the porafilter and makes extraction so much better.

One thing I can tell with certainty. The result of extraction is an extraordinary drink. I did not have a chance to have a better espresso anywhere else. I can certainly tell that espresso foam is called “crema” for a good reason. When you drink espresso with good crema it tastes somewhat similar to Crème brûlée.

I am not sure if anyone is reading these posts. I am tempted to put little teasers in my posts to figure out if anyone is lurking here. Here is another teaser. Let me know about your existence by following me on Twitter, or by registering to this web site and I will share with some tips on getting great green coffee beans in Toronto or on the Internet and on really easy way to roast them.

To appreciate complexity of making a consistently good espresso take a look at the chart below.

It is not enough to say that OK espresso comes out of being between the two lines separating too sour and too bitter ends of it. One has to stop extraction at the moment when there is a right balance between sourness, bitterness and other flavors.  Some baristas let first sour drips of the coffee to go in the drip tray and then put the cup under the flow. But, unfortunately, the most complex flavor is in these first sour drips. Without them the shot looses multiple facets of flavor.  Sourness is a background that attenuates  complex flavous. If it is not sour, the taste is not pronounced enough. To figure out role of sourness, try to have a sip of good espresso right after having a bite of orange or a sip of orange juice. Not having enough bitterness does not help either. First, bitterness is a taste of caffeine. If you do not have it, the espresso has no punch.

If you appreciate whiskey, grappa, schnapps, or cognac, you would know that their complex taste is coming from spirits other than ethanol.   Ethanol is the base of it, but the flavor is in heavy spirits that are called “tails”. Too much tails in the drink give you hangover, but enjoyed in moderation and in skillfully made drink, they are exquisite. This is what we are paying our money when we go for a shot of 33 year old Glendronach or Camus. The same idea, but the time frame is different. Your espresso is good fresh. The flavor lasts for a couple of minutes. What a wonderful reminder of   impermanence!

My favorite coffee is Ethiopean Yogercheffe. I like roasting it to full city about 10 second into the second crack. It is better than all espresso blends I tried so far. To be fair, I did not try too many yet. I am sure some blends are as beautiful as the Yogercheffe.

I love sniffing espresso aroma right after pulling a shot. I think if I have made a perfume (and I can do it, but you do not know about this hidden passion of mine yet) it would be wonderful!

Update

Now I think I figured that out. The problem was in the bad batch of coffee roasting. A thermocouple on my roaster broke down and I was terribly over roasting the beans. All sugars were caramelized and there was no more sweetness in the bean left. I changed the thermocouple and  things are back to good and very good.

I started to install the PID on my Audrey. Fist, I decided to find out what is going on by just observing the temperature as I pull a shot. I have read on the net that the optimal temperature for most blends is 109C or 228F. Well, it turns out that the boiler heats up to 118C! This is an overshot by 9 degrees. When I pull a shot, the temperature goes down to 101C (213F), but the heater does not start until the boiler cools down to 96C (205F). Now I know exactly why I need a PID! Precision of 7o degrees  is bad!