onemoreshot wrote:Is this the screen you use on a regular basis?

Yes, it's the one on most E61's I've seen. The flipside is shown in the photo below (right), next to the "dot" one I mentioned earlier.


Groovy on the right, ungroovy on the left

Well, here they are...my first shots using a naked PF on the Anita (Mazzer Mini grinder, brew pressure 9.9 bar, beans are from Whole Earth-French Roast):

http://s4.photobucket.com/albums/y147/H ... ta-1st.flv

http://s4.photobucket.com/albums/y147/H ... ta-2nd.flv

I think I'm stopping the pull a little on the late side (too much blonding), so I'm open for suggestions on how to improve my technique. My video skills also need a lot of work

To tell you the truth, I couldn't really see all that much from the video ... it looked like the pour was starting off black and crema-less and the finished product only had a few mm of crema ... is that correct? I could tell that the espresso was lightening, but couldn't see if it had blonded ...

... anyhoo, I'd definitely dial the brew pressure down to 8.5 or 9 bar. Seems much more forgiving and it seems to reduce the sharp increase in pour speed throughout the pour. 9.9 bar is craazy! For some reason, I've always found a large double basket to be a lot more forgiving than the 3x basket that you seemed to be using.

Other than that, from what I could see, your pours looked good ...

Hope that's somewhat helpful,

Luca

luca wrote:To tell you the truth, I couldn't really see all that much from the video ...

Yeah....I was afraid about that. I'll play with the lighting in the kitchen to get a better picture.

I hate opening the Anita because the screw holes don't exactly line up...so it's hard to re-install the cover.

I would have to concur that the extract looks crema-less, that is normally a bean issue. Do you know what the roasted on date was?

On both videos you had two streams from the PF. While that is not necessarily a bad thing, it does suggest an uneven distribution. The center is not extracting evenly hence the two streams, sometimes.

You appear to be using a triple basket, the shot looks to be a bit fast and watery. It should be more syrupy and goopey (is that a real word?). Turn down your pressure (personally I run 8-9 bar depending on the machine) and try a different blend, I bet you will get better results. For a first time it is not too bad. I did not see any channeling jets and the extractions were not lopsided, relatively even. You are going down the correct path, now practice practice practice...

If I remember correctly, the Anita has a vibe pump. One trick setting the pressure, use a blind basket (backflush basket), let the pressure ramp up and make note of it. Turn down the OPV (over pressure valve) and repeat. I adjust my Isomac to .5 bar higher than I want with the blind basket. When you switch to you normal basket with coffee, you will get a slight drop in the pressure v.s. the blind basket. So 9.5 with a blind will be 9 with coffee, 8.5 will be 8 etc... at least it is on my vibe machine. My rotary pump only drops about 0.1 bar using that method but rotary pumps are another beast.

These are great suggestions. I appreciate the feedback and tips.

The beans are store bought from Whole Earth, but I'll take a look at the package to see if I can find a roasting date. As everyone mentioned, they're almost guaranteed to be old (therefore, only about 1/4" of crema). Some Ambrosia is on it's way so hopefully it will get here in time for the long weekend.

Yes, it's a triple basket. I'm guessing I didn't quite fill it as full as it should (about 18grams).

Thanks for the tip on adjusting the pressure with the blind basket. I had it at 9.5bar but turned it back up. So I'll turn it down a little. I think I'm trying to adjust too many things at one time so there are too many variables

I agree with Dave, the pour looks like very tired beans. Decaffeinated coffees will sometimes pour like that. But let's look at the two pours more closely:


#1: Fast, dark beading in donut shape

I blame loss of adhesion with the sides for donut extractions (rapping, grating on lock-in) if it's later confirmed by premature blonding at the perimeter and weak center flow. That doesn't occur in the next seconds, so center-weighted distribution faults are the next likely culprit:


#1: Twin inverted towers collide as perimeter flows merge

The total pour volume was 1.5 ounces in 40 seconds. While there are signs of unevenness both in color and flow, it's not grossly out of whack, again supporting the assertion that the grind is super-fine to compensate for stale beans. Using fresh coffee and the WDT are my recommendations.

Given the dramatic change in the extraction, I'm assuming the next pour was after an adjustment:


#2: Two ounces in 22 seconds

A triple basket holds around 19-23 grams of coffee. If you underdose too much, the puck will not expand to meet the dispersion screen, which can increase the chance of channels developing. This pour was fast and accelerating when you cut it off. If there was no major adjustment, my guess is transversal channeling (i.e., a fissure between layers in the puck developed because of uneven pockets and excessive headspace during the puck expansion).

I don't have video, but here are a couple of photos. When you fill the basket, dose it to the top, the distribution techniques are many at this point. I do a simple NSEW sweep with the side of my finger. The result is an even coffee bed level with the top of the basket. Then tamp and lock your PF into the group, then remove it. If the top of the puck is cracked and broken you have too much coffee in the basket.

After the extraction, the puck has swelled in the basket. My best pours, the puck expands and makes slight contact with the shower screen leaving a light impression like this...



The shot from the above puck about half to 2/3 through the shot (that is a double basket, about 17g of coffee)


I did not notice the donut Dan points out, I was rebuilding a Citrix server and did not notice. Your Ambrosia will do the trick. Keep in mind that Tony recommends about 5 days post roast before use. He roasts Monday, Wednesday, Friday. I find the blend to be too sharp and baking soda tinged until about the 3 or 4th day post roast.

As you mention, don't change to many variables. One thing at a time, watch, taste then adjust.

OK, got the Ambrosia beans and made a video:

«missing video»
Again, sorry about the quality (and poor camera work). It's from a digital still camera.

The fresher beans yielded a better pour, but my tamping is still off (pinhole sprays, etc). I've still to try the WDT, and that will be my next step.