Now that I've started putting filter papers in the basket and worrying less about how this may affect my cholesterol measurements, I just read a new thread that (only) suggests changing how coffee is dosed and ground when using those papers. It's an admirably technical piece of research done primarily by Jim Schulman with contributions by others in the HB team. Here's the link to it:
How filter baskets affect espresso taste and barista techniqueAfter a first read, I gather that different baskets with different amounts of perforation and differing levels of uniformity of the holes affect the taste of a fresh, hot shot with crema, specifically that baskets with holes engineered to finer tolerances and allowing faster flow because of more cumulative holes tolerate a finer grind up to a certain dose and thus allow more structure in the flavor of the shot while somewhat taming the intensity. Too high a dose at this finer grind, and the shot is unpleasantly intense. I think I'm interpreting that correctly. Here's a quote from Jim on what he means by structure and taming unpleasant characteristics of such more intense, higher-dose shots:
another_jim wrote:The higher the dose, the punchier tasting the shot. This punch is a combination of astringent, cutting and bitter flavors that wine lovers get from tannic wines, and which they call "structure." The higher the dose, the more structured the shot; the lower the dose, the creamier and softer tasting the shot. Since this effect disappears as the crema dissipates; this structure difference is clearly caused by differences in the crema of high and low dose shots.
Italians like soft and creamy espresso; but Seattle and West Coast espresso typically has a lot more punch. Five years ago, West Coast blends were medium roasts and had low acidity; and one could get away with overdosing a double basket and grinding coarse. With the advent of more acidic and brighter SOs and blends, the choice with a conventional double is to grind finer, dose lower, and give up the punch; or to make a very rough shot with coarser grinds and higher doses. The VST 18 gram baskets uses the same grind as a conventional double at 15 grams. This means it delivers the high dose structure without the unacceptably rough and sour taste of under-extracted, lightly roasted coffee. This may explain why some people strongly prefer the VST18 or Strada baskets.
Another finding in that thread is that baskets with more holes that are more finely engineered are more sensitive to variations in dose, such that consistency is difficult to achieve with anything equal to or less precise than a Mazzer Super Jolly grinder.
That thread leads me to wonder whether those of us pulling shots through filter paper may benefit by updosing a bit to achieve more structure while benefiting from a similar taming effect.* Also, I wonder whether paper at the bottom of the basket makes the brewing technique more or less tolerant of inconsistencies in lesser grinders. In other words, are excess fines (randomly small particles) less of an issue when filtered out by paper? I am not suggesting that filtering espresso through paper is a way to optimize flavor over dispensing with the paper and using only a metal filter basket. This is for those of us willing to compromise flavor somewhat for a healthier brew (but further discussion of that is off-topic for this thread).
I believe that those of us who are interested in paper filtering of espresso are relatively small in number and doubt that there's to do similarly rigorous testing. But I personally want to start with updosing some filtered shots and tasting them against lower-dosed shots without filter paper. I'll be interested in others' responses to the thread on filter basket differences as to whether it applies to pulling espresso through filter paper.
* I'll concede that my expectations may be "off" because the effect of pushing espresso through the tiny holes in paper could bring into play very different effects than pushing it through the larger holes in a metal filter basket. Why? The filtering effect may be very different with the smaller and possibly more varied holes in paper, especially with regard to substances such as lipids clinging to each other at one side of the paper. I also concede that I am not yet even considering the effect of differences in filter baskets when pulling espresso through paper. And, I acknowledge that I don't have the scientific training or the cupping expertise to test or analyze this subject with anything like the rigor that Jim Schulman and other HB members applied to their filter basket study.