Hi,

Im still getting to grips with my Bezzera BZ10 and learning a lot along the way I have a question though about the water pressure when pulling a shot. It seems there is a lot of variation in the pressure, according to the pressure gauge on the machine, when pulling shots and im not sure if its because of:

1. the bezzera just fluctuating
2. my grinder not being consistent over grinds (Baratza Vario)
3. dosing inconsistency?
4. tamping inconsistency, doubtful?

Sometimes when pulling multiple shots i will see the pressure go from 6 bar for one shot to 11.5bar the next shot which seems odd. I also mean that it stays at that pressure throughout the shot. Can the machine be *that* sensitive to differences in tamping and dosing or is there an issue with my machine, grinder. Keep in mind that i have already calibrated my grinders setting as well as time to dose so im not fiddling with the settings from shot to shot and there shouldnt be that much difference between dosing amounts seeing as i run the grinder for the same amount of time every time.

Happened again this morning. For some reason, with no grinder changes, pressure was at 6bar throughout the shot and pulling way to quickly. Took me 30mins to get back to normal.

Any ideas?

thx

Interesting. My first guess would be a problem with the vibratory pump. Perhaps there's an electrical problem, e.g. the pump doesn't perform right when the heating element is on due to, say, a wiring problem. Or perhaps there's something in the pump preventing the plunger from sealing consistently.

Does the pump sound different when it's putting out 6 bars vs. when it's putting out 11?

Nice Machine! Where in the US are you located?

How many grams of coffee are you using in those Bezzera baskets - they like about 12, maybe 13g's, unless you opted for the slightly larger 14g baskets.

I would put the blind basket in and adjust the max pressure to 9.0 bar as the BZ10 is reading the pressure just prior to the grouphead. It's a PITA to adjust this pressure but . . .

You have downloaded the parts manual here? - http://www.bezzera.it/home_ing.html

lotOfLatte wrote: For some reason, with no grinder changes, pressure was at 6bar throughout the shot and pulling way to quickly. Took me 30mins to get back to normal.

Hmm, on second thought this is striking me a bit differently than my first reading. I would think that, if you're preparing your basket well, using good coffee, and selecting an appropriate dose for your machine, you'd get a slower-pulling shot when the pressure's low (all things being otherwise equal). a 5 bar drop seems a little crazy, in particular, but maybe It's just been too long since I used a vibe-pump machine. If you're seeing higher flow and a pressure drop, there's a decent chance that's normal and you may need to look at your coffee selection, dose weight, and distribution prior to assuming an issue with the machine. Setting the pressure as per Eric's suggestion may up your forgiveness factor as well, making the machine act more consistently for you.

erics wrote:Nice Machine! Where in the US are you located?

How many grams of coffee are you using in those Bezzera baskets - they like about 12, maybe 13g's, unless you opted for the slightly larger 14g baskets.

I would put the blind basket in and adjust the max pressure to 9.0 bar as the BZ10 is reading the pressure just prior to the grouphead. It's a PITA to adjust this pressure but . . .

You have downloaded the parts manual here? - http://www.bezzera.it/home_ing.html

Hi Eric,

Thx for the response. I am currently using Counter Culture's Toscana blend and really enjoying it, when i can get a decent shot that is As per their guidelines i am dosing at about 19.5 grams using the original double basket that came with the machine. There is probably a lot less left over as a lot falls out when i try to distribute the espresso by leveling it out with my finger?

Re your other question when i back flush the machine with the blind basket i get around 11.5 bar consistently. I downloaded the pdf in your link but to be honest i think it might be a little beyond my current skill level. Not even sure what im looking for lol.

For what it's worth, how much coffee you put into the portafilter basket prior to distributing and leveling is a useless measure of dose weight if your puck preparation includes leveling off "excess" into the trash (or whatever). The number that matters is the dry weight of the coffee that you use in actual brewing, the weight AFTER you knock all that stuff off. If you're not being consistent about leveling, particularly if your routine includes any tapping down, then your dose is likely to be rather inconsistent.

It sounds like your machine is fine (if you always get 11.5 bar against a blind filter), and sounds like you need to find out what your dose really is, adjust it if necessary, make sure that it's the same every time, and make sure that any leveling of the coffee you do (whether tapping, stockfleth's move, etc.) is the same every time as well.

Not even sure what im looking for lol.

And hence my question as to where are you located - I happen to know a couple of experts in Houston, TX and Silver Spring, MD. who can show you exactly what you are looking for and what to do with it.

You need a 0.1 gram scale badly and you can't/shouldn't go past 13 grams with the basket that came with the machine. 1st-line offers a 14 gram Bezzera baskets - http://www.1st-line.net/cgi-bin/category.cgi?item=5471009&type=store - I bought two and recommend the same for you. Yes, there is a multitude of other baskets on the market but, without going into a long story, stick with Bezzera for now.

Bezzera machines have the same group bell as an Elektra. They like to have head space. If you are dosing to the top of basket, you are probably over dosing. The puck will hit the shower screen and crack which will cause channeling and could give you a low brew pressure.

Ok, looks like i am making some progress on this at the expense of a lot of epresso.

erics wrote:And hence my question as to where are you located - I happen to know a couple of experts in Houston, TX and Silver Spring, MD. who can show you exactly what you are looking for and what to do with it.

You need a 0.1 gram scale badly and you can't/shouldn't go past 13 grams with the basket that came with the machine. 1st-line offers a 14 gram Bezzera baskets - http://www.1st-line.net/cgi-bin/category.cgi?item=5471009&type=store - I bought two and recommend the same for you. Yes, there is a multitude of other baskets on the market but, without going into a long story, stick with Bezzera for now.

I have a gram scale and tried your suggestion above although i found if i use 13 grams (whole espresso beans) then after grinding/distributing it doesnt even fill to the top of my double shot portafilter before tamping, which makes it a little hard to distribute. Is that normal? Is there some sort of guidelines on how to go about finding the right amount of espresso for your basket?

Lastly how then does the supplier guidelines, 19.5 grams, 1.5-1.75oz in 26 secs relate? I guess what is the most important number amongst those figures? Obv the dose is way to much for my machine, so should i basically assume that regardless of the blend i should always does around 12.5-13grams? How does that affect the other numbers?

Thx again

Remove the springs from your portafilters (PF) and set aside. Grind the 13-15 grams into a spare cappy cup, fluff them up with a small stick (5 seconds) and spoon them into your tared basket resting on the scale to 13 grams. Your portafilter is nice & toasty in the machine.

Smooth & distribute the grinds in the basket, set the basket in your spare PF and evenly tamp. Flush a couple of ounces (max) through the grouphead, insert the basket in the PF and brew away. As a starting point, adjust the grind to give you a 25 second +/- shot of 26-30 grams of espresso.

I happen to use the double spout PF as a tamping stand and the single spout to brew but this is a personal choice. Try this for a day or two and if you don't like the results, well, back to your regular routine.