Bad Science: how much is 25mls in 25 seconds?

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Lancelink
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#1: Post by Lancelink »

Hi All,

Something that's bothered me about the most basic instructions in defining your grind is the maxim 25-30 mls in 25-30 seconds.

Seems pretty straight forward right? But, reading through various threads on various sites, including this one, right down to the instructions that accompanied my Rocket Giotto Premium, I've noticed a startling inconsistency and, well frankly, bad science.

Standard espresso 101 advice for establishing your grind appears to be this:

1. Lift the lever, pour 25-30 mls (including the crema).

2. Adjust the grind until it pours in approx 25 seconds.

3. Time future shots by stopping at the very first sign of blonding.


Where's the argument then?

Well, to start with when does this shot start? Some insist as soon as you lift the lever. Others, when the "pour" begins after pre-infusion. Pre-infusion on my Giotto takes about 6-7 seconds.

That 6 or 7 seconds is ample time to ruin a shot. It certainly matters.

Next we ask: how do measure 25mls - does that include the crema?

The stock answer on is "yes." But from any empirical standpoint, that's not going to cut it, no matter who taught it to you in the first place. No matter how much it's received knowledge. It's bad science. It's even bad economics. Sorry, I know I'll get howled down and directed to the FAQ. But it's wrong.

Measuring to the point of crema will always be faulty logic. When your beans are fresh (even moreso for some roasts) you will end up grinding too coarse. And/or as the beans age, you will end up with an over-extracted pour. On top of that as the crema settles, your espresso proper may end up as little as 12 mls of extract. We all know it, but we ignore it because someone else said to. True?

In fact, it's hard to think of an instance where measuring the crema point could go right for you.

So it's my contention that the policy should be this:

1. Time the pour from the sight of the first drop of extract. If that's more than say 10 seconds, grind coarser and start again.

2. Measure under the crema.

Whether 25mls in 25 seconds remains the yardstick is another matter, but I'm guessing yes.

Finally, the issue of how to recognize blonding.

I'm going to call shenanigans on this one too. I can't for the life of me pick what's supposed to be blonding with any consistency. Heck with some beans it looks blond from the first drop. If I relied on that to stop every shot, I'd be a nervous wreck.

Now I know, ultimately it's what's in the cup that counts, but we still have to get the basics established before we can move on to subjectivity.

Thanks for reading.

Lance

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tekomino
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#2: Post by tekomino »


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HB
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#3: Post by HB »

Lancelink wrote:Well, to start with when does this shot start? Some insist as soon as you lift the lever. Others, when the "pour" begins after pre-infusion. Pre-infusion on my Giotto takes about 6-7 seconds.
Jim offers a compromise in What is the correct method for shot timing?
another_jim wrote:Machines vary from 3 to 10 seconds dwell time (from pump turn on to first drop). Since half the people say go from the pump, and the other half say go from the first drop, I give my shot times based on half the dwell time plus all the flow time.

It may not be right, but it seems the most reasonable way of comparing long dwell with short dwell machines.
Lancelink wrote:I can't for the life of me pick what's supposed to be blonding with any consistency.
It's a bit harder to describe, but I judge by the "pucker" of the extraction cone and translucency of the stream. I elaborate on this point in When did this espresso extraction go blond? It's not dependent on color and pucker/translucency works across all the espresso machines I've used.
Dan Kehn

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Randy G.
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#4: Post by Randy G. »

Ignoring the cross-posting....
Lancelink wrote:Measuring to the point of crema will always be faulty logic.

So... How big of a cup should I get?
This was a double of about 60ml. Should this count as approximately 0ml at this point?

The point being, there is no rule. Many of us have been saying for a long time that the so-called "rule" is merely a starting point to be used by those starting out, or possibly tuning a new grinder or new machine. From that starting point the fine-tuning of the variables comes into play with only one thing that matters - taste. If all you do is stick by quantitative science and ignore the art, then all you have is a cup of hot brown liquid.
EspressoMyEspresso.com - 2000-2023 - a good run, its time is done

Lancelink (original poster)
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#5: Post by Lancelink (original poster) »

tekomino wrote:Lance,

Here you go: Digital espresso or a way to consistency

:D
Good lord, I thought I was being pedantic.

Thanks, I think....

Lancelink (original poster)
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#6: Post by Lancelink (original poster) »

HB wrote:Machines vary from 3 to 10 seconds dwell time (from pump turn on to first drop). Since half the people say go from the pump, and the other half say go from the first drop, I give my shot times based on half the dwell time plus all the flow time..
Yes, it's quite a muddle isn't it? Which is why I asked the same question.

Seems to me whoever came up with the 25 in 25 maxim in the first place merely got quoted verbatim and it was passed along like an urban legend. (If you want to see one that's dumber, and dare I say, completely braindead, google "fellini move". When you see the source for that advice you'll laugh or cry depending whether you're wrestling a La Pavoni and haven't yet worked out they're too temperamental to give two remotely similar shots in succession.)

So given that there's no consensus as to when the timing is meant to start, and the policy of including the crema is so flawed it can't be justified, yet so accepted that it verges on negating anything approaching a starting policy, I'm wondering whether the entire maxim should be thrown in the let's start again basket?

But unfortunately, when you're adjusting your grind it's actually really useful to have a benchmark place to start. And that is, how long (roughly) should I let the pour run, and when the crema is settled, roughly how much espresso should be in the cup?

Or am I trying to make it too easy?
.

Lancelink (original poster)
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#7: Post by Lancelink (original poster) »

Randy G. wrote:Ignoring the cross-posting....

<image>
So... How big of a cup should I get?
This was a double of about 60ml. Should this count as approximately 0ml at this point?
Hardly. But it's not 60mls either is it?

Especially if you buy into the notion that crema is something to be discarded.

http://www.jimseven.com/2009/07/06/video-1-crema/
Randy G. wrote: The point being, there is no rule. Many of us have been saying for a long time that the so-called "rule" is merely a starting point to be used by those starting out, or possibly tuning a new grinder or new machine. From that starting point the fine-tuning of the variables comes into play with only one thing that matters - taste. If all you do is stick by quantitative science and ignore the art, then all you have is a cup of hot brown liquid.
Yes it is, but even as a starting point it isn't defined. Like I'm asking in this "starting point," when does the pour start, and when does it finish?

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HB
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#8: Post by HB »

Randy G. wrote:Ignoring the cross-posting....
Indeed, I see another parallel discussion here. For those new to this site, cross-posting is strongly discouraged for reasons explained here.
Lancelink wrote:Yes it is, but even as a starting point it isn't defined. Like I'm asking in this "starting point," when does the pour start, and when does it finish?
As tekomino noted, measuring by weight eliminates the "do you include the crema" question. AndyS proposed the idea in Brewing ratios for espresso beverages and it's been my standard ever since. As for when to start timing the shot... well, pump on is good enough for me, but for those who want to account for differing dwell time for preinfusion among various espresso machines, Jim's compromise seems reasonable.

I no longer get hung up on dogmatic adherence to standard brew pressure, pour time, temperature, etc., if only because these metrics change slightly between different espresso machine designs. On the other hand, if the goal is to calibrate identical espresso machines, it's reasonable to closely compare these metrics.
Dan Kehn

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Randy G.
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#9: Post by Randy G. »

Lancelink wrote:Hardly. But it's not 60mls either is it?
Says who?

The image in my previous post shows a Bormioli two ounce espresso cup, and the top of the handle closest to the glass points to a level that, if I remember correctly from when I bought the set about 6 or 8 years ago, is almost exactly two ounces (60ml), or at least close enough to count. I can check it again for you if you like.
Especially if you buy into the notion that crema is something to be discarded.
I could throw away the crema, wash the glass, and just have the fun of making espresso, scientifically.. personally, I prefer to drink it.

All the measurements, decimal places, temperature readings, timings to a tenth of a second, and weighing doses to a tenth of a gram are all meaningless if the espresso is not to your liking. It's fun to talk about (maybe not this time so much), but the journey, in the case of espresso, is not the goal - the beverage is, and however you achieve it is what counts. I have had miserable 25 second pulls, and I have had wonderful 40 second pulls.

And in my experience, a blonding stream does not taste bad. It lacks body and the flavor is thin, but not necessarily bad. What it does to the body of the espresso may not be to your liking, but I think far too much emphasis is placed on it. My feeling is that this is perpetuated by new home baristas to a great extent. They see a blonding stream, taste the espresso, and blame the bad taste on the blonding. I think that regardless of when such a pull was stopped it would have tasted just as bad- possibly with more body and a fuller, richer bad taste though. :wink:
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mitch236
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#10: Post by mitch236 »

I don't get hung up on how to time a shot. I agree with Dan in that when the pump is activated works for me and here's my explanation:

I only use timing, measuring, weighing etc... to adjust the end result to my liking, on my equipment. The parameters I end up using work for me. It is very difficult to translate those to others with different equipment. If you search out some posts by another_jim, you will read his reasoning for not providing exact parameters for finding a sweet spot in his reviews.

I have realized a few things since backing off from asking every little question and just reading what's already written:

1. I now weigh every shots grounds before brewing and keeping the dose within a few tenths of a gram.
2. I weigh every shot that I brew while dialing in a blend and figure out what time gives me the best taste. Once the shot's volume/time is determined, I don't need to continue to weigh the shot.
3. I don't try to measure volume in a shot glass.
4. I try extremes and see how it affects taste. Its fun and educational.
5. Consistency is KING! (see above)

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