Newbie: Flow color vs weight to stop extraction

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#1: Post by Tacit37 »

Hi everyone,

I have had my rocket appartamento for almost 2 months. I am able to get 18g in an about 40g out by timing the shot. If I go by flow color, 18g yields about 54g out. Is this normal? I want to get the technical aspects down so that I can start fine tuning by taste.

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#2: Post by MNate »

Most of us don't cut the shot by time, but rather use a scale under the cup and stop the shot when it gets to the desired weight. We usually aim for a ratio of the weight of the grounds (18g is great) to the desired weight of the beverage, often 1:2 So 36g of liquid (usually here stated backwards as 2:1, just FYI)

Then we might look at the time it took to get that amount and if it took too long we would grind a little coarser. If it got that weight in 10 seconds we'd grind finer.

But then we'd start thinking about if this really is the right ratio and time for this coffee. I don't think many go by a blinding point anymore, but it can be very useful to try your espresso in its staged by doing something like the rule of thirds to help you know if you should change your recipe:
Good Extraction, Good Espresso - Espresso Guide
Rule of thirds?

Experiment! Have fun! And definitely go by taste in the cup above all!

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#3: Post by BaristaBoy E61 »

I would also add to the above advice that is very good, that after that if I still can't achieve a taste profile that I like, I look to our freezer to see what beans are lurking there that might be mixed to our primary bean of the moment to find a more satisfying cup by blending coffee beans on hand.
"You didn't buy an Espresso Machine - You bought a Chemistry Set!"

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#4: Post by Nunas »

All good advice so far. I'll add that it depends also on the type of beans and the degree of roast. Some will blonde more quickly than others. Also, you need to consider why you're pulling the shot. If it's a straight-up espresso shot, then it will be mostly the desired taste, aroma, mouthfeel, and so on. Nominally, less then 1:2 (grinds in:coffee out) will be a ristretto, between 1:2 and 1:3 a normale (which is what most people call an espresso shot) and over 1:3 a lungo. In the real world, you just have to keep trying all sorts of ratios with all different coffees to settle on what you like. It can be more complicated if you are also making milk drinks, then you have to consider the effect of the milk. When most people start doing cappuccinos and lattes, they wrongly think that the taste and mouthfeel of the coffee are less important, so pull it long (who cares). Somewhere, recently, there was a thread about whether the coffee matters. Fact is, it matters a lot. Counterintuitively, using a lower ratio for a milk drink will usually be better, as the stronger coffee comes through the milk better. The bottom line is you just have to mess about for some years or do a lot per day until you get everything to the point where you don't even have to think how to produce various coffee beverages consistently.

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#5: Post by another_jim »

I go by flow color. If the flow isn't mostly clear; then you haven't fully extracted all the solids. If you haven't fully extracted the coffee; it's taste will be distorted. If you're looking for lungos, ristrettos, X:Y ratios, 38.7 second shots, etc, etc, adjust the dose and grind to hit those bench marks as the shot is beginning to flow clear.

The point is real simple ... if the shot is not clear by the time you get to whatever benchmark you are looking for, it will always taste better if you wait for it clear. If the shot is flowing clear before you hit your benchmark, it will usually be a denser, more espresso-like version of what you would get at your benchmark. Heather Perry of Klatch roasting, two times US barista champ, taught me this long ago, maybe fifteen years or so, when most people, including me, were stopping shots a lot darker. I've never since that time had a coffee that was better tasting when it wasn't flowing clear, or that improved when pulling it longer. It's just about the most invariable rule I know.
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#6: Post by EricLuhrs »

I find your comments intriguing. But can you say more about what you mean by "clear?" Is this blonding?

Thank you.

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#7: Post by another_jim »

Yes, but more important is translucent. Just ruin a shot by letting it run on and on while observing. There's a point where the stream is translucent and also strongly whitening the crema where it enters.

This is not a precise guide, but a way to know that your grind and basket are appropriate to whatever recipe you are using. If you follow a recipe and the shot is flowing clear for a while before, or still dark and foamy at, your recipe's cut off point, then you are using the wrong grind, dose, or basket for that recipe.
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Tacit37 (original poster)
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#8: Post by Tacit37 (original poster) »

Wow! I am glad I asked. So this morning I did cut off solely based on weight, and this makes it easier to adjust up or down with the grind. I am still playing with this. Thank you!

The other element of translucence that AnotherJim brought up sounds like it does have to do with blonding if I am reading correctly, and in which case, cutting off by watching blonding and looking at factors of "recipe" or time and weight seems to be what he is suggesting.

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#9: Post by Peppersass »

Tacit37 wrote:...cutting off by watching blonding and looking at factors of "recipe" or time and weight seems to be what he is suggesting.
Right. Ideally the shot turns translucent when the beverage weight reaches your desired brew ratio. That way, you have the desired strength with complete extraction. This should give you a balanced shot, neither overly bitter or sour, with all the flavors the coffee can offer up (well, sometimes tweaking temperature will improve flavor, but that's yet another variable you have to play with.)

When dialing in, time is only helpful in a gross sort of way, generally to indicate that the flow rate is way too fast (gushing) or way too slow (choking.) For most coffees, chances are that if you pull 36g of beverage from 18g of grounds in less than 20 seconds or so your shot will be under-extracted. The effects of a really long shot time, say longer than 45-50 seconds without playing games with flow/pressure profiling, are harder to predict because they vary with the coffee. A dark roast is likely to be over-extracted, bitter and ashy, while a light roast might end up under-extracted because a too-fine grind choked the machine and not enough water ran through the puck. In any event, when dialing in "traditional" (non-profiled) shots, I just look for the shot to finish somewhere in the 25-40 second range and adjust from there. I'm much more concerned about the low end of the range than the high end, especially when pulling light and medium roasts, which don't over-extract easily.

However, once you dial in, pull time is your indicator for consistency. If the time it takes for the shot to blond at the desired brew ratio changes more than a second or two, something has changed and likely the shot won't taste like it did when you dialed in. Could be aging of the coffee, an inherently inconsistent grinder, a hopper with not enough beans, poor puck preparation, poor temperature or pressure stability in the machines, etc.

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#10: Post by EvanC »

This is intriguing. Then, there are those of use using manual machines who have a limited amount of water, so we have to hit the blonding stage before we run out of water in the grouphead. :roll: