A first look at the 18g VST Basket

There's been a lot of talk about VST baskets, a lot of people buying them, but I haven't seen a lot by way of review or 'first look'.  So when I recently discovered that Square Mile are selling 18g VST baskets online I decided to go for one.

It arrived today nicely boxed up, and inside were two pieces of paper which seem to be the results of quality assurance tests. They include a chart showing the normal distribution of hole sizes, presumably to make sure they conform with manufacturing tolerances.  That's a really nice touch, and although I'm a little confused by the fact that there are two different results sheets (and hence I wonder if the sheets actually relate to my basket or whether they're just thrown in from a pile in the despatch room) but it certainly makes me feel better about spending £22 on the basket!

Here are a few pictures, alongside my bog-standard gaggia classic basket from Happy Donkey.

18g VST Basket

Left: VST.  Right: Standard Double.

Significantly Larger Bottom
(I like big bottoms and I cannot lie!)

Straighter walls leading to the
larger base

Standard Double Basket

VST

It clearly has a larger base with more holes than the standard basket.  I'd like to go into the dynamics of how this should, in theory, affect extraction, fines migration etc... but to be honest I don't fully know at this point in time. Something to add to my learning goals.

It is actually not too dissimilar in appearance to the triple basket I received with my bottomless portafilter, although as the side view shows the triple has a larger basket volume.

Let's make some shots.
I thought that first I'd use my Gaggia Classic standard double basket, to provide a basis for comparison.

** I must point out here that the beans I'm using were roasted about 6-7 weeks ago and are therefore quite lacking in crema, so both shots on the videos below actually look a bit flat.  I'm not particularly happy with the appearance and extraction of either shot.  But the beans still taste great, and I'm mainly using them because I want to give the Square Mile Summer Espresso (that arrived with the VST basket) a few days to degass. At that point I'll post another blog specifically concerning taste.  In this post I'll focus on visible differences in making a shot of espresso ***

I've taken photos at various points... measure, dose, distribute, tamp... to see if there is a visible difference between the two baskets during these stages.

STANDARD DOUBLE BASKET:
Just over 18g of beans.  I'm aiming for around 27 seconds for approx 2oz and an espresso weight of about 30g, which is a 60% brew ratio (or 1.67 if you prefer using a multiplier to refer to brew ratios).  This is approximately what I always aim for and obtain, once all factors are dialed in correctly.

18.18g of beans

 

Grinds pre-distribution

Modified WDT

After Stockfleth Move

After tamping with Espro tamper

Video of extraction:

18g VST BASKET:
Same parameters as above, same targets.

Same measure of beans

After grinding,
no visual difference

WDT again. I don't
notice a difference in
the basket.

Stockfleths.
There's a very minor
difference. VST slightly
larger than standard.

The main difference with the tamp
is that the basket is slightly larger
so the 58mm Espro tamper
is not such a perfect fit.

 Videos of extraction:

The first shot ran a little too quickly, so I tightened up the grind two notches.  But that was too tight, as the second shot was a little slow.  Here are both, for the sake of completeness.

VST Video 1, starring Biggins our birman cat.

VST Video 2.

Here is a photo of two spent pucks. 

VST on left, standard double basket on right.

With the pucks knocked out of the portafilter and bottom-side up, it's easy to see that a significantly larger surface area at the base of the puck is used for extraction.  As the VST puck is more cylindrical than the slightly conical standard double basket, the grinds seem to be spread over a wider area and hence the puck seems softer.


CONCLUSIONS (visual inspection, not taste):
I can find no material differences in the volume of the VST basket compared to the standard gaggia classic double basket, so making the transition to VST seems an easy switch from that viewpoint.

Dosing and distribution seem to work very well using the Weiss Distribution Technique combined with the Stockfleth Move to ensure an even distribution in the basket.  As I always use those anyway, once again the transition doesn't seem to require any adjustment on my part.

There is no notable difference in the height of the tamped grinds in the basket, so no fear of the grinds being any closer to/further from the shower screen than previously.

With my first extraction using the VST I thought perhaps that it produced a higher TDS due to the increased weight in the glass compared to the standard double basket shot (42g versus 30g), but then surmised that the weight increase must partly be due to the additional volume in the glass in that VST extraction, so the weight could not be used to conclude anything.  Indeed, in the second VST shot the weight went down to 25.5g... coupled with the volume falling to an estimated 1.75oz, due to the grind being too fine that time. Again, it is therefore difficult to conclude anything.

In advance of tasting the espresso, which I shall leave for another post, the main visual difference is that the espresso flow did not blonde at all during extraction, whereas with the standard basket blonding did begin to occur around 22-25 seconds. I'd expect this to lead to a sweeter shot, which would marry up with many user's comments. 

As a prelude to a taste test, I gave my wife the first VST shot in a latte without any indication that it was different from what I usually give her.  I asked for her opinion and she said it was "Great".
"Compared to yesterday's?"
"Yes... better."
"Why?" I asked.
"It has no hint of bitterness at all.  It's very smooth"

I can't wait to try it with fresh beans!