Grind v Tamp v Cake - Relationship

Honest_Gaza

Obviously, there is a direct relationship between the fineness of grind and the pressure of the tamp.

In mathematical terms, I'm guessing that  :
Grind + Tamp = Crema (meaning, the coarser the grind, the more pressure is required in the tamp....and the finer the grind, then less pressure is required in the tamp)   feel free to correct me if I am wrong.

A bi-product of the Grind and Tamp process (apart from the Crema that is produced), would be the "cake" that is left behind.  Again, I'm guessing that it shouldn't be too sludgy.

This morning I've been experimenting with Grind and Tamp and having various degrees of success with the Crema & Cake that has resulted. Perhaps, too much spare time on my hands  ;D

If the guage on the front of the machine is any indicator (I think it is probably indicating pressure required to force water through the grind), I am frequently tamping too hard as it is indicating an "over extraction".
I have set the Solis Maestro Pro to the "Espresso" setting (between "Drip" and "Turkish")....and would assume that some tamping is required.

As mentioned, the guage is frequently indicating an over extraction.  If I cut back on the fineness of the grind, the resulting espresso seems too "runny" to me as it drops from the PF....and a sludgy cake is produced

Am I paying too much attention to the guage ?
Should the aim be to produce a grind that is so "correct", that tamping is not required ?
Should I find another hobby ?

Please ease my confusion.  ???

Remus

i don;t know about your guage, not familiar with it. i do know that i pay absolutely no attention to mine at all. experimenting between grind and tamp is that fine tuning that can take ages to get right. from my experience the cake should be solid, well defined and appear almost dry on top. if there is water at the top of the cake then your grind is too fine and the water is not purging thru the coffee enuf. when i knock out the cake from my pf, it comes out cleanly in a well formed solid mass leaving the pf almost clean. you definately need to pressure with the tamp to get a good solid formation so that the water runs thru the coffee. if it is not tamped firmly you will have the water running all over the place unevenly. i can't imagine not tamping at all to mean a perfect grind ? not sure. remember that 20-25 second extraction trick to get it right. start with a coarser grind and work the way back. in fact, i remember starting out that i used bathroom scales to get the tamp feel right when i started. the ida is to get the tamp as considtent as possible so that the different grind settings is your variable for flow. i would guess by what your saying that your grinding way too fine. turkish coffee for instance is an extremely fine grind that will clog up your machine every time...very smooth powdery texture. i reckon you could kick it back 2-3 notches and be around the money. guessing of course.

Honest_Gaza

Thanks Remus.  Just to clarify....I'm not setting it for Turkish.  Turkish is at one end of the scale on the grinder and there's approx 7 settings before you hit Espresso, and then further settings for coarser grinds. I'm about 9 settings away from Turkish...and 2 settings past Espresso....heading towards Drip. You have made a valid point about the length of time for the extraction though.  I'm well below 20 secs and therefore getting a pretty wet cake at the end of it.  As you've suggested, I'll go for a slightly more coarse grind and heavier tamp.

Unknown

It's called a PUCK, not cake.. the name puck is a better description because you should be producing a fairly solid puck ie: being able to knock it out of the basket and pick it up with two fingers without it breaking apart.  This is something that I could not achieve with my old Breville.   I find that a fine grind (hard to explain in words) with moderate tamp.. moderate tamp meaning about 12 - 15 kgs of force (yes I used bathroom scales to test it).  I've started to use the polish method after I tamp also, it gives the dose a nice even finish on the top before it goes into the machine. Also, watch for the little shower screen screw indentation on the top of the puck once the coffee has been extracted.. this is a good measure to see if you are using the right amount of coffee. I use a digital scale now that is accurate to 0.1 grams.  Silvia is best (at my grind setting) with 15 grams of coffee in the double basket.. Hope all this helps.. Paulie PS: don't stress, finding the right grind, tamp & extraction time (and the combination of these) is the best thing about making espresso at home.. you'll get it eventually..  8)

FreshCoffee2

Gary, you are right in that there is a relationship between (type of beans ie density), fineness of grind and tamp. Did you also mention dose? Cant remember, I've just skimmed over your post quickly. Rule number one in my "book" (and probably Pinot's excellent reference book ;D) is you must fill the filter. "Fill" in this case meaning, not to the very top, but to the point where when you apply the group handle to the group, you just get a whisker of an imprint from the shower on the top of the tamped grinds. Then you can worry about fineness of grind & tamp. A heavier tamp pushes the grinds together more and results in a smaller puk, so filling the filter as stated abopve, is dependent on how hard you tamp. Make coffee. If it doesnt extract properly, and you have filled the filter as above and tamped "consistently" to an arbitrary pressure (say 15 kilos as measured when tamping on a bathroom scale), then the only variable than needs to be looked at at that point is the finess / coarseness of grind. Adjust as necessary & repeat until you get the extrction you want. It is finicky, you do get variation, do not become obsessed!  ;D I am not familiar with the pressure guage on your model but it sounds very much like a "back pressure" gauge as also used on some other domestics. If this is the case, actually, its not a bad "tool" for novices. It will tell you what you want to know, as long as you have first filld the filter & tamped consistently as already noted above, because if (according to the gauge) you are over or underextracting, you only need tpo adjjst grind, repeat and wattch the guage. It is simply a mechanical device to tell novices exactly the same thing as experienced operatiors can tell you from just looking at the flow & sampling the brew. Having said all the above, I am an afficionado of overfilling the filter, tamping well ( even up to 20 kilos...who cares as lonmg as you are consistent in your own technique) and thereby setting a slightly more coarse grind. It gives a more rich, smoother coffee. No sugar for me. Others apparently do the same but beware, it (overfilling) can be hard on the equipment. Hope this helps, it's not that hard, and I repeat dont let it become an obsession!   Regardz, FC.

nzroaster

You should get a solid puck which you can cleanly break in half and see whats going on with your distribution. Havent got time to find it for you but Malachi(spelling?) has some excellent puck diagnostic stuff on the net.

FreshCoffee2

Ah yes and with regard to getting some (or a lot

Remus

I'll go for a slightly more coarse grind and heavier tamp.

imo that will work the best. just trial and error. if you see it pouring our really watery, you know you go up a notch. and so on and so on. to really give you a kicker, once you get it right, make sure your note down the coffee type somehwhere and hwat grind setting you have it on. if you buy different beans next go you may need a different grind setting and it can be very frustrating if you don;t record what you've done. my simple way to remember this stuff is i have a sticky label on the inside of the cuoboard door i store my coffee in and i've just put down coffee type and grinder setting on it to refresh my memory. maybe i get confused cos i have different grinder settings for the 2 diffferent machines i have at home...maybe i just have a pisspoor memory...i dunno. :D it may sound anally retentive but its the best way to guarantee that the coffee you are extracting is the best it can be. you have a good machine, a good grinder. my philosophy is get the absolute best out of it !

Honest_Gaza

Thanks guys. The one thing that I've probably been ignoring is the amount of grind I am using.  I believe that I'm possibly underfilling....will experiment further. FC....it's too late about the obsession part....I think I'm goooonnnnnnnee.

Honest_Gaza

I mentioned earlier that my extraction time was significantly shorter than the target 20-25 secs.  I made a cappa this afternoon and timed the extraction time.....7 secs (nearly freaked me out)  :-X So as per previous suggestions, I changed the grind setting, payed more attention to the fill level and exerted a little more tamp pressure. The result.....23 sec extraction time and a pretty damn good puck at the end of it.  The sad thing is that the drinking of the coffee has become of lesser importance  :D I'm amazed how the slight change in variables can change the end product.  Obviously, a person making upwards of 100 coffees a day will attain a level of consistency.  Pretty hard for your average garden variety home coffee drinker to achieve this level of consistency.....but I'm sure as hell gunna try  ::)

nunu

Try to keep at least one variable constant, like the tamp.  If you tamp consistently, I find adjusting the single variable often yields the better result.  Otherwise you'll be fishing around for ages. 20-25 seconds is nice for 15-20mL.  Try 30 seconds for 30mL.  Even get a graded shot glass to see how the pour is going. If you can't see an imprint of the screw on the coffee, it's obviously underdosed.  If you need an extension to your group handle to get the portafilter locked in place, you've obviously overdosed.  We're talking about a few millimetres of coffee, maybe half a gram either way.

Reschsmooth

It is incredible how almost imperceptible changes to dosing can make a difference. A gram more and you can choke the machine, a gram less and you get a 5 second gusher. However the other problem for home baristas is that we don't have many kilos of coffee to play with over a short period of time. I may try to pull 5 shots or so to get grind settings right with a new blend. However, the next day, the beans are, well, a day older, and you may find the grind setting is no longer appropriate. But hey, we don't do it just to drink coffee do we?  ;D P

Unknown

Hey HG! I just remembered.. you should (if you haven't already) go out and buy yourself a decent tamper.. I started using my Silvia with the silly standard plastic one and always had trouble tamping consistently.. I went to Toby's estate and bought a 58mm tamper that fits the Silvia basket perfectly.. it made all the difference.. I can consistently pull 45 second shots (i like it slow)!! A decent stainless steel tamper will cost you between $25 on ebay and $65 for a Pullman.. Luck!

FreshCoffee2

Please be careful with evil-bay et al...there is very little visual difference between a tamper that fits snug, and one that is only 1 mm smaller in diameter... What I'm saying is, sometimes you get what you pay for, and very often, it's not what you though it was! So the good quality tamper ends up costing its own price, plus the 25 dollars (plus postage) wasted on the tamper that didnt fit! Regardz, FC.

nunu

Good advice on your 500th post FC.   A lot of times we're looking for bargains, as we do.  There's nothing wrong with looking for the best deal, but you really have to beware of people selling off items at a ridiculously low price. While a 1mm discrepency might not look like a whole lot, just think of around the edges of the portafilter.  There's somewhere not being tamped enough.  If you tamp to get the previously untamped edge down, you're overtamping the rest.

FreshCoffee2

Thanks for that Nunu, I hadnt noticed until you pointed it out it was my 500th post! The point is, if you spend money to buy a tamper that fits...then it should bloody well fit!    A discrepency of even just a humble millimeter (in the case of say, picking up a cheap 57mm tamper as opposed to a more expensive 58mm jobbie for a regular commercial size filter), still amounts to the purchase of a tamper that doesnt fit...so why bother? Chiz, FC.

Unknown

Well FC, lets leave that up to HG.  For anyone on a budget, I believe that a tamper that is 1mm smaller than the inside diameter of the basket is not a problem.  My ADVICE is genuine... the standard tamper is hopeless for novices like me to get an even tamp, primarily due to its diameter. If I measured the inside diameter of my basket and it was 58mm for example, and I ordered a 58mm tamper from "evil-bay" as you call it, I would expect one that fits quite closely.  If I (or anyone else) ordered a "58mm tamper" and was delievered something different, that is something I would take up with the seller. >:(

FreshCoffee2

My post was not intended to offend, certainly not anyone on a budget, it was only just to make people aware...as in "buyer beware". Kind Regardz,

Honest_Gaza

Paulie, FC....the tamp that came with the Sunbeam EM6900 appears to me, to be a reasonably solid hunk of plastic with stainless steel base.  Certainly a lot more useful than the plastic straw with disc that came with my previous Sunbeam machine.  As such, I am assuming that it is performing it's function correctly. In a review of the machine that was on "coffeeco.com.au" the reviewer went into great detail on the mechanics of the machine, possible shortfalls in the PF and baskets....but didn't mention the Tamp as an issue.  So I'm hoping that it can be considered as "within specs".

mattyj

HG, when I had a look at the 6900, the tamp was one thing that impressed me. It wasn't as heavy as I was expecting (and I probably commented on that as a negative), but from holding it, and checking it's fit with the basket, I was really impressed. I would also imagine that being a bit lighter, it would provide some really good 'feedback' as you tamp - you'd be able to 'feel' the coffee as it's compressing into the basket.

nzroaster

HG, somebody pointed out keeping your tamp consistant and changing other variables. This is the best way to do it because it is hard to measure your tamp everytime. Once you get it right though its all practice. In regards to the tamper diameter, the 1mm makes a huge difference as if your outside 1mm isnt tamped it causes channeling through the sides. Remember, water is very lazy and will travel the path of least ressistance. If there is 1mm around the outside of your puck that is tamped less than the rest, it is sure to create channeling. If you havent found out already, channeling is becoming a major focus for barista and home coffee fanatics alike. Have you tried www.coffeeparts.com.au ? They have decent (price and quality) tampers.

Unknown

Anyway, I was just trying to be "honest" Gaza The difference that my "near enough is good enough" tamper has made is great.. PS: I measured my Ranc baskets and the tamper that I bought with a micrometer before I bought it.  I was just trying to suggest the different options. Enough on tamp, Gaza is happy with the Sunbeam one which sounds like it's a lot better than the standard Silvia tamper.   Paulie

Honest_Gaza

As I've continued to fiddle for the last couple of days (using the advice you have all given), it appears my main problem has been the "fill" level. I've been underfilling and as someone (I think Remus & Paulie) suggested earlier, this results in a collection of water at the top of the basket which produces the lovely slush I was complaining about in the puck. While this is possibly an obvious requirement for the seasoned coffee baristas.....it's easily overlooked by us beginners. My wife....she just looks at me and shakes her head at my new obsession :D

Remus

HG i have personally found that the slush at the top of the basket is more due to a grind that is a little too fine. so maybe check that aswell mate. simple physics, (believe me it must be simple if i suggest it  :P ), that even if you underdose; if the grind is correct then the water is still passing thru the coffee, down the pf and into the cup. why would you get water at the top if you underdose ? this is actually a question more than anthing cos i double + dose everything so i truly don;t know. to me though, if water is at the top of the basket like sludge then something is preventing the water passing thru the coffee. that suggests that either the tamp is too hard or the grind is too fine. great to see you're enjoying the process though mate. like you mentioned b4, it's not just about the coffee anymore is it !!  :D

Remus

FC you've mentioned "evil bay" a few times b4. have you had a bad experience ? i've used ebay for years and rarely had a prob. even had my manual pavoni machine shipped out from europe with no dramas at all.

Honest_Gaza

HG i have personally found that the slush at the top of the basket is more due to a grind that is a little too fine. so maybe check that aswell mate. simple physics, (believe me it must be simple if i suggest it

Remus

Well that's my theory....which is it ? Genius or Idiot (no offence taken)

buggered if i know mate. i just like the taste of coffee. lol ;D

FreshCoffee2

Ok fellas, with regard to slush at the top of the grinds in a situation of under dosing, here's the explanation... how so ever badly... explained: At the end of the brew cycle, there is a pressure relief from the top of the shower, back through the group... A correctly filled filter is one where coffee grinds are touching the shower. The pressure relief goes back up through the shower/ group and out the electrovalve into the drip tray. So the liquid is "sucked" back up from the puk, which is still in contact with the shower, leaving it "dry". In an under filled filter, ie one where the grinds are not up to the shower, when the top level of liquid / pressure is relieved away from the shower area, the liquid /slurry has dropped to below the level where it is in contact with the shower, the pressure relief stops, leaving the rest of the slurry wet........ Apoliogies for crap english explanation, but the idea is there. And separate to the above. Subject to all other opinions being just as "worthy" as mine on this one, evil bay is a place that allows people that might have taken their junk to the tip, to instead sell it to someone else that will later, take it to the tip for them! I realise this is a gross generalisation, but I see an awful lot of coffee equipment junk being palmed around just like that, and in some special interest forums where an awful lot of talk goes on, subsequently making icons and legends out of crappy old equipment that never worked well even when it was new. This may sound harsh tbut there is quite an element of truth in it from my point of view which is that of an experienced equipment dealer. Certainly there are some bargains to be had in there but I see people that dont know, buying the wrong bargains! Anyway like I said, just an opinion. Regardz, FC. Ah and forgot to mention....and of course this certainly is biased, evilbay is also a haven for discount artists to destroy the service industry by operating from warehouses and selling cheap. No shopfront, no repair/service facilities as such, no resposibility for warranty, no employment of staff, therefore generation of taxes, no deliveries, just cheap "appliances" with no care, no reponsibility... You want help, you go elsewhere because you wont get it from the vendor who incidentally, probably knows nothing about the equipment he's selling...may as well be selling nuts and bolts. I did say biased, diddle I!

Reschsmooth

FC, so would an appropriate analogy of your comments re pressure relief, wet pucks be, say vacuuming up water from carpert (with a wet & dry vac of course) - if you hold the vac nozzle (do you know I needed to look up how to spell nozzle?) above the carpet, you won't suck up any water, but if you hold it directly against the carpet, you will suck up more water? By the way, with ebay, at the individual level, it is nothing more than a garage sale - hey, I sold a Jack Daniels bottle display light that was collecting dust for about $120! At the 'wholesale' level, it is just another way to sell goods on the internet to cut prices because of no service and questionable warranties - that maybe fine if I am buying an illy cup, but buying a coffee machine, which is a mechanical device requiring some skill, is different. My 4c P

FreshCoffee2

P. Regarding your analogy with a vacuum cleaner on carpet...yes, that's basically what I'm saying, thanks for deciphering my jumbled explanation. Sometimes its hard to finds the right words. I like your reference to "garage sale". That seesm quite appropriate to me. I realise there will be plenty of people who will agree with what I am about to say, but at the same time will also disagree with my dislike for it,  because they will reserve their right to maximise their dollar, but for me a one word description of evil bay, or one of the main reasons why many use it to buy coffee machines, is the simple word "cheap". Very often however the lowest price is not the "best" price. Anyway enough of that from me, someone asked, I replied! Regardz, FC.

Honest_Gaza

FC...thanks for the technical explanation on the grind level within the PF.  I was so impressed with my own explanation I never believed there would be an alternative answer  :D As for E-Bay, I've used it many times for buying and the occasional selling.  I can only offer positive comments on all of my purchases except for one case (which was quickly resolved, and a refund given). As previously suggested, for specialist items, probably not the best place to shop. However, I have recently got into digital photography and, like coffee making, this often means further purchases of accessories.  I can honestly say that I've been able to source accessories via E-Bay (and other internet sites), which are not readily available via normal retail avenues. So for me, I give it the thumbs up.....but I'm aware it's not everyone's cup of tea (or coffee)