question re my shots

texx

i have been having a problem with my shots just lately seems to me its since we had some good rain in the last week or 2 , the shots are a little watery (thin) most times but not all the time , now and then i pull off a good one but i have been calling them a fluke .
everything is the same in my setup as its always been when i was pulling all good shots every time .
my question is how does humidity affect a shot cos our humidity is a lot higher the last few weeks than it normally is only other thing i can think of is that my grinder burrs maybe need replacing .
any thoughts would be interesting .

johno

Ronin

My guess is the humidity. Moisture in the air will swell the coffee grounds in the puck. What I have experienced is I will need to fine the grind to get a decent pour, humidity swelling coffee grounds in the group chock the shot. I've not had watery shots in humid conditions tho Hope it helps

texx

thanks for the replies , after giving it more thought i am thinking it is a combo of 2 problems the main one being the unusualy high humidity we are getting here the last few weeks ( i have taken my grinder in one more notch , but looks like that aint enough) also my burrs maybe getting a bit worn now which would be why the marks i have on my grinder that show where i normally run it are probably out because of wear , so both those things means the grinder needs to be adjusted in further than i normaly would . i will mess about with it a bit today if i get chance and see if i can improve on it . the burrs have done about 150kgs of beans by now, whats the average for a set of burrs ?? its a K5 grinder.

texx

thanks AM , i have been using the same bean for quite a while now (a columbian from beangreen). but i will look into another set of burrs today , from memory i had a bit of trouble last time they were a bit hard to find , anyway i will get onto it today .

Dry_bean.

We face the opposite problem here on the Copper Coast, lack of moisture, as the roasted beans age over a period of 7 to 10 days I have to grind progressively finer to get the same result in the cup. I realise this is the opposite to what your experiencing however just thought I would include this to reinforce AM's post re coffee beans and moisture, or lack of.

mycuppa

As a rough, general guide, you can expect around 250kg from small burr grinders, 300kg from medium and up to 350kg from the larger burr grinders. Conicals, such as the large mazzer and compak run between 900kg and 1.2 ton, although I have a cafe running a pair of K10 conicals and we can't seem to get more than 800kg from genuine burrs. Genuine burrs seem to last almost twice as long as 3rd party burrs. Only use kilos as a prompt to inspect, because inspection is the ONLY way to know for sure - and that means removing the top assembly to get a good look at the burrs. Unfortunately, most people don't know what the approx. wear point is on the burrs, so you may find like I did on a recent K6 that the original burrs after 500kg were still fine, but we replaced them anyway. K5's use quite a small set of burrs, from memory I think they are < 60mm. The beans and barista techniques play a major part in the wear pattern. I have a customer who grinds our house very fine and doses low, so he chews through blades at almost 1.5 times the rate of comparable cafes. How a bean is roasted is very important. I have just started supplying a cafe who were previously getting their beans from a local "micro" roastery using a "low-end" drum roaster. We found the beans from their previous supplier quite dark roasts (much darker than mine) in external appearance and extremely hard to the point I believe they were not adequately roasted, e.g. dark on the outside and very light on the inside - the color of the ground coffee was a complete contrast to the exterior. The subsequent effect of grinding these beans over many months caused the burrs to wear at incredible rates (along with highly inconsistent coffee). The customer was usins a new grinder with the factory fitted burrs and it lasted a woeful 100kg - on our advice, the customer looked at the burrs and it was "game over". At 150kg, I would urge you to inspect the burrs. You might also gain some insights by trying a completely different pack of beans not roasted by you to see if you can consistently get the shots to match back-to-back. This is a process of elimination.

derrilex

Apart from the dodgy grind, is there a definitive way to tell if your burrs are shagged ? Is there a wear indicator or something or a standard test one can do ?

Lacehim

on 1358494977:

Genuine burrs seem to last almost twice as long as 3rd party burrs.

I totally agree with that.  I've experienced genuine and generic burrs, and in my experience they are very different.  Buy genuine, buy once! It wouldn't hurt to get a spare set of genuine burrs to test.  If that's not the issue, you put them away as spares. 

FreshCoffee2

on 1358494977:

.........How a bean is roasted is very important. I have just started supplying a cafe who were previously getting their beans from a local "micro" roastery using a "low-end" drum roaster. We found the beans from their previous supplier quite dark roasts (much darker than mine) in external appearance and extremely hard to the point I believe they were not adequately roasted, e.g. dark on the outside and very light on the inside - the color of the ground coffee was a complete contrast to the exterior. The subsequent effect of grinding these beans over many months caused the burrs to wear at incredible rates (along with highly inconsistent coffee)...."

Which is why professional methods of colour coding roasts such as Agtron rely on comparing grinds to the colour chips rather than beans. And while admitting up front to adding nothing of value to the discussion, I had a good belly laugh when I read the passage quoted. In the coffee game its a contradition of epic proportions. Fledgeling "microroasters" sweating over their low end low cost geriatric design coffee roasting machines, reinventing the wheel, seen in the eyes of many as being the passionate artistic types turning out "specialty origins and coffees", while people in the industry with background and experience using high quality modern roasting equipment are seen as the evil old establishment. Its a marketing coup of unfathomable proportions. Way to go Jeff !

mycuppa

:D A., I forgot to add the part about the super-shiny, super-clean, micro-drum roaster (sans flue) strategically placed in a prominent posy inside the cafe, drawing an alarming amount of admiring attention and Oohh--Aaahhs. Add to this image their unshakable self-belief they were the only 4th wave coffee haus operating in the city and I must have heard it 30 times in the space of an hour. "we are the only ones doing it like this anywhere !" Yep - they sure were in a category all on their own - just not sure if it was related to coffee though.

mycuppa

In terms of how to check the wear on grinder blades. Experience and intuition are one measure - you just get to know by looking at the blades over and over, or you can use AM's suggestions. From a practical point, there is a simple test I like to apply (although it does consume a bit of coffee). Run the grinder for a few minutes using say +/- half a kilo of coffee (or less for smaller grinders). If it's getting hot and the smell of burnt coffee is evident, then you know the burrs are stuffed. This method is essentially relying upon emulating the practical duty cycle of a cafe during a busy period. Very few home grinders go through the volumes to worry about wear, except if you have somehow got hold of an ex-cafe grinder. For cafes, it's a numbers game and you are recommended to use conservative judgement - if in doubt, replace the burrs as it's a relatively cheap investment that greatly assists in producing excellent and more consistent coffee. I have a bad habit of lifting the doser chamber lid of cafe grinders and smelling the ground coffee. Seems my nose can't stay out of trouble.

UNM

on 1358659523:

Very few home grinders go through the volumes to worry about wear, except if you have somehow got hold of an ex-cafe grinder. .

A surprising number of people on fora such as this use ex-cafe grinders. I am one of them. My burrs were definitely  stuffed. I went for low cost burrs, presumably generic. Only genuine ones available were the long life version at $240. Generic $42. Assume  generic wear more quickly than original. Let's say a life of 100kg. I get through 350gram a week approx. They will last  long enough for me.  simple arithmetic.

derrilex

on 1358505465:

OPPSS. Chippy = no fingers so can not test burrs  :pan

Loose the odd fingernail here and there but all digits in tact - so far  :D

Dry_bean.

After 5 years of use I replaced the burrs in my Rocky with a generic set, got less than 6 months out of them, replaced them with a set of Rancillio burrs and they were still going strong when I sold the machine almost 5 years later.

texx

got my shots back to the way they should be today . bit of tweeking with the grinder and a little lighter tamp and we are back on track , a very nice thick slower shot with tons of crema . had a traveling customer this arvo got a double short black and loved it ,.actually asked about our beans and would we sell him some , so all good and i am happy again . i have ordered another set of burrs but they can go into my spare parts for the time being . johno

coffeehorse

on 1358714369:

My burrs were definitely  stuffed. I went for low cost burrs, presumably generic.

Assume  generic wear more quickly than original.[...]I get through 350gram a week approx. They will last  long enough for me.  simple arithmetic.

I've done a taste test on 3 Robur-E's - generic burrs, mazzer burrs & blunt mazzer burrs, and while I was earplugged and in a separate room to the grinders, I was able to correctly taste the genuine burrs after 0KG and 30KG on 3 separate origins and two grind sizes for each origin. 18/18 may not 'prove' anything, but it was certainly nice to know. I guess I'm saying the most important thing is 'taste' rather than 'price'. Cost per kg is not really a big issue on grinder burrs, IMO. In the same way that clarity of flavour improved when moving from flat > conical grinder, bluntness of burrs plays a similar role to a greater or lesser extent.

askthecoffeeguy

For me I'm always keeping an eye on shot quality and trying to erasure all the variables If I know my burrs have had a good workout and its taking more effort than I would like to get a less favourable result - then that to me is a good indication that burrs may need changing On average we change ours twice a year in the cafe and it seems to do the trick - also keeping all equipment regularly serviced whether it seems to need it or not reduces wear and tear on equipment and reduces the likelihood of equipment failure or breakdown ...