From Silvia to e-61 and back: the effects of pressure profile on texture?

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Tag Team Jesus
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#1: Post by Tag Team Jesus »

Three years ago, I was getting amazing textures of espresso with my PID Silvia that has been modified with a pressure gauge to read pressure near the coffee puck (gauge mod credit goes to the brilliant George Gillespie of Jeepin Geo fame). But I kept hearing about how much easier it was to get great espresso with an e-61 machine. So, I took the plunge and tried out an Alex Duetto and ultimately settled in with a PID Alexia (I only make espresso).

Just as promised, Alexia's e-61 made it easier to get a centered extraction without channeling, or two split streams, etc, etc. Also, underneath the crema, the body of the e-61 shots seemed clearer of the blond, murky emulsification thingies more typical of Silvia. What I didn't anticipate, however, was the texture of the espresso to be so different. Gone were the bubblier shots from Silvia that seemed more effervescent and lighter in texture (do I recall hearing them fizz a little in the cup and they seemed to float down my throat?). The extractions I got from Alexia were denser, as if they had been thickened with gelatin compared with Silvia's shots. And I wasn't sure I liked this denser, more gelatinous mouthfeel I got with the e-61. Well, I never quite figured it out then because I quit drinking coffee for 2 years....

...but recently, I came back to this delicious hobby and have again been comparing my PID Silvia with my PID Alexia. Now, with two years time to clear my palette, the difference in textures is still immediately salient to me. Each machine gets the same coffee. Same Macap grinder. Same basket and dose. Same SD3C Watlow PID controller set at what I believe are the same brew temperatures (no Scace though). And yet, quite different textures.

Anyone else ever notice such a thing or have any thoughts? Regardless of preference, I think there has to be a difference in texture/density of espresso between these machines. Is this difference an attribute of the pre-infusion of the e-61 group vs. the all-at-once pressure profile of the Silvia?

And when all else is going right for each machine, I think I almost prefer the lighter textures I can achieve with Silvia over what seems to be denser, more gelatinous shots I get with my e-61. The fact of the matter is, I guess I really miss the textures I got with Silvia. NOTE: this is not to say I don't get great flavor out of Alexia. This is a discussion about textures/density of espresso in the cup. Even with food, I think about texture a lot.

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another_jim
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#2: Post by another_jim »

I agree there are texture differences between machines. I don't not sure what the reasons are: LMs without long preinfusion also produce heavy textured shots, while lever machines, which have long preinfusions, tend to produce lighter ones.

On the same machine at the same pressure and temperature, if you use different baskets, using the same coffee, same grind, and same brew ration and time; you also get different textures. So my guess is that this has something to do with the actual dimensions of the basket, group and brewing volume, and how that affects the crema formation.

One of the main problems is that there is even less of an accurate vocabulary for mouthfeel than there is for taste.

Heck, this is a coffee site; and even here the spell checker doesn't believe "mouthfeel" is a legitimate word. Talk about the a topic still in the dark ages.
Jim Schulman

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Tag Team Jesus (original poster)
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#3: Post by Tag Team Jesus (original poster) »

I have definitely noticed Blue Bottle's lever machines here in San Francisco produce some rather light textures. But, Silvia has lighter textures with no pre-infusion while the e-61 is quite dense with pre-infusion. Very interesting.
another_jim wrote: Heck, this is a coffee site; and even here the spell checker doesn't believe "mouthfeel" is a legitimate word.
Ha! I noticed the same thing when I was typing my original post.

dman777
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#4: Post by dman777 »

Would the texture of the espresso from s commercial machine at a coffee shop be closer to the Silvia or the Alex? Strictly speaking of texture.

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Arpi
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#5: Post by Arpi »

I've noticed a difference in the cup between the Expobar Brewtus (E-61) and the Gaggia Classic but didn't paid attention to the texture. At first I thought it was due to the different OPV valve setting but both machines produce different cups. The Gaggia Classic has a temperature swing during the shot meanwhile the Brewtus is more flat. The GC doesn't have much preinfusion while the Bretus does. In the GC, the initial water rushes out faster and with a higher water debit (not measured). So all those differences probably add up to make a difference in the cup.

Cheers