Bike cafés: a questionnaire

General cycling advice ( NOT technical ! )
Cyril Haearn
Posts: 15215
Joined: 30 Nov 2013, 11:26am

Re: Bike cafés: a questionnaire

Post by Cyril Haearn »

rmurphy195 wrote:
Cyril Haearn wrote:this is getting as uninteresting as the thread about motorcycling :?

No-one forces me to read either thread :wink:


Agreed - I can't find the core of what people are suggesting to the OP in all the long-winded discussions about coffee roasters - should these (along with this post?) be shifted to a coffee roaster thread?

Maybe we should force ourselves to read them, to keep our brains going :wink:

Where are the railway threads?
Entertainer, juvenile, curmudgeon, PoB, 30120
Cycling-of course, but it is far better on a Gillott
We love safety cameras, we hate bullies
Airsporter1st
Posts: 792
Joined: 8 Oct 2016, 3:14pm

Re: Bike cafés: a questionnaire

Post by Airsporter1st »

rmurphy195 wrote:
Cyril Haearn wrote:this is getting as uninteresting as the thread about motorcycling :?

No-one forces me to read either thread :wink:


Agreed - I can't find the core of what people are suggesting to the OP in all the long-winded discussions about coffee roasters - should these (along with this post?) be shifted to a coffee roaster thread?


The clue is in the title -"cafe" (can't add the acute accent on my tablet). A great deal about a successful cafe hinges around the quality of the coffee served, so I think it only reasonable that a good portion of the threads discuss the best way to make it.
Brucey
Posts: 44666
Joined: 4 Jan 2012, 6:25pm

Re: Bike cafés: a questionnaire

Post by Brucey »

re temperatures/pressures in a Brikka; this

http://coffeegeek.com/forums/coffee/machines/478669?LastView=1544232250&Page=1

suggests that it has a 55g weight over a 1.83mm dia hole, and that the pressure is therefore about 2.0bars before the water is able to go through the coffee grounds. If so then the water won't boil before 130 degrees C.

However it is possible with any similar machine that the first flow of water occurs before the water actually boils; the reason is that the trapped air in the top of the reservoir expands considerably well before the water boils, and this will push water through if the pressure gets high enough. Therefore the coffee grounds in a standard Bialetti are probably wetted with non-boiling (cooler) water well before the water boils and indeed this may happen with a Brikka too (indeed the valve may leak air at a lower pressure than 2 bars and will only make the full pressure/temperature when the boiling is quite vigorous and liquid is being forced through the valve).

Once the main flow of boiling water is pushed through it has to heat the wet grounds to get to the extraction temperature; it might be that the grounds start out at ~70C and migrate to ~95C during the main flow, it might go higher than that. Someone posted in the link above that "it doesn't taste like it is brewed at 130C", and indeed it probably doesn't get that high. Still don't know how hot it gets though...

cheers
-------------------------------------------------------------------------------
~~~~~~~~~~~~~~~~~~~~~~Brucey~~~~~~~~~~~~~~~~~~~~~~~~
Canuk
Posts: 1105
Joined: 4 Oct 2016, 11:43pm

Re: Bike cafés: a questionnaire

Post by Canuk »

The Brikka—-

A variation on the Moka, the Brikka features a modernised weighted pressure valve, which essentially acts as a pressure cooker. This means less vapour is released from the valve, so that pressurised water reaches the upper chamber at a much lower temperature. This lower brew temperature is similar, and perhaps slightly lower than the 92/94 degrees widely applied to pour overs and opens a new world of possibilities for this old-fashioned charmer.

Thats a review from a Barista forum. The general consensus seems to be that your can make excellent coffees on both the Moka and the Brikka of you follow the #rules :

1. Always use cold filtered water to start with.

2. Make sure the basket is completely clean and dry before adding fresh ground cofee,ground to a consistency of rough sand, no finer.

3. Do Not tamp the coffee, fill and make a soft mound with which the screw top will gently compress itself.

4. Heat on a medium plate only, the whole brew to boil should take no less than 5 minutes.

5. When the upper chamber is 80% full, immediately take it off the heat and set to one side for two minutes till be process is complete.

Follow this and you'll have an expresso experience every time. Some people, when they take it off the heat plare the Biletti in a pan of cold water, to stop over brewing which can give a bitter taste. The secret to these Biletta does seem to be the valve and the fact that the coffee is wetted long before any very hot gases get to it, around 90-94C.
Brucey
Posts: 44666
Joined: 4 Jan 2012, 6:25pm

Re: Bike cafés: a questionnaire

Post by Brucey »

given the pressure cooker effect on the boiling point it seems a bit counterintuitive that the brewing temperature would be less in a Brikka; has anyone actually measured it? Is there is a big difference in the airspace above the reservoir fill in a Brikka? Does the weighted valve leak steam at a slightly lower pressure, or seal perfectly vs liquid or gas?

Found lots of talk (and some interesting measurements/tests) about standard Bialettis here

https://www.home-barista.com/brewing/how-to-improve-your-moka-pot-coffee-t48638-40.html

and a load of measurements here

http://www.msc.univ-paris-diderot.fr/~phyexp/uploads/Moka/article2.pdf

I've used a moka for decades but didn't fully appreciate the importance of the fill level before, or the importance of making sure that there really are no leaks (eg from the safety valve). Both can significantly change the brew temperature, more than I'd expect.

cheers
-------------------------------------------------------------------------------
~~~~~~~~~~~~~~~~~~~~~~Brucey~~~~~~~~~~~~~~~~~~~~~~~~
slowster
Moderator
Posts: 4661
Joined: 7 Jul 2017, 10:37am

Re: Bike cafés: a questionnaire

Post by slowster »

Canuk wrote: I'm very tempted by this Hasbean offering. It should arrive today.

Canuk, if you've bought whole beans to grind yourself, and if you also plan to try making espresso with them, I would add that I often found it quite difficult to consistantly pull good espresso drinks from the single estate Hasbean beans, not least because the beans in the subscription change each week and I would routinely struggle (with my frankly mediocre skills) to get the grinder dialled in each week, often wasting quite a bit in the process. It's not helped by the fact some single estate beans can be very intolerant of getting the grind/dose right (conversely, every so often I would get a very easy bean which would give good results almost no matter what I did). Incidentally, before using the beans to make espresso I always wait a week or so after the date of roasting to let the beans de-gas.

I stress that I think that my problems probably reflect my personal skill level: I think a lot of other people are able to dial in their grinder for the new beans each week with only one or two shots. Moreover, it's completely different using the beans in a commercial setting, where it's normal to waste a few shots to get the grind dialled in maybe once or twice a day, because after that dozens or even hundreds of drinks will be made and sold before the grinder needs adjusting again.

Congratulations on the getting the donated espresso machine.
Post Reply