Typical third wave coffees are lightly roasted and harder to extract. It the roast was a little off, it will be even harder to extract (this happens often, unfortunately).
Have you tried a dark roast? Starbucks might have just what you need. I think it is fairly easy to get extraction numbers much higher with a dark roast compared to your typical bleeding edge light roast.
jpender Senior Member Joined: 11 Jul 2011 Posts: 742 Location: California Expertise: I like coffee
Grinder: OE LIDO Vac Pot: S/S Moka Pot Drip: Aeropress
Posted Fri May 18, 2012, 9:14am Subject: Re: Calling All VST Refractometer Owners - A Brewing Challenge:
I don't have a VST refractometer (or a press pot for that matter) so I'm technically disqualified. I also suspect that Netphilosopher has tried this at least half a dozen times in his Coffee Research Utility Kitchen, so it's probably near to impossible if not impossible.
But I made a half-hearted attempt anyways. I bought some pre-ground coffee while traveling last month that I don't like at all. It's sitting in the freezer for just this sort of thing.
I added 36.0g (it's a drip grind) to 175g of hot water. Simmered and stirred in a saucepan for 8 min. Poured into inverted Aeropress. Used enough additional hot water to rinse coffee from pan and utensil into AP and top up to 236g total slurry weight (18% brew ratio). Pressed.
148g beverage, 87g wet grounds (1g went missing).
Dried the grounds in the oven for a little over 2 hours until weight stablized. Cooled: 29.8g That's a yield of 17.2% and a beverage strength of 4.2% (including some undissolved solids).
Not even close.
By Netphilosopher's theory the effective extraction was only 24%, less than what I'd have guessed I'd get by boiling grounds for 8 minutes.
Now the really weird thing is that although the coffee was way too bitter, it was also delicious. I drank it.
GlennV Senior Member Joined: 27 Oct 2011 Posts: 29 Location: UK Expertise: I love coffee
Posted Sun Jun 3, 2012, 2:51pm Subject: Re: Calling All VST Refractometer Owners - A Brewing Challenge:
I did had a go, with a criminally over roasted sidamo, espresso grind, 8 mins in a bain-marie to keep the temperature up, and it only got to 4.6%. Underextracted by all the usual formulae using a 2g/g water lost or retained ratio - I didn't dare taste it! I do find the argument for using all the brew water for extraction yield calculations, for immersion methods, pretty compelling. What I don't understand, though, is how this squares with the fact that those with far more tasting experience than me are recommending 19-20% yields for both drip and immersion methods, with the usual formulae. For example, the Nick Cho video on youtube showing his clever dripper technique would come out at about 22% yield using all the brew water for the calculation ("Gold + Paper + Clever", which is certainly a full immersion technique as he pulls the grinds out of the brew in a Gold filter before the drawdown).
Symbols: = New Posts since your last visit = No New Posts since last visit = Newest post
Forum Rules: No profanity, illegal acts or personal attacks will be tolerated in these discussion boards. No commercial posting of any nature will be tolerated; only private sales by private individuals, in the "Buy and Sell" forum. No SEO style postings will be tolerated. SEO related posts will result in immediate ban from CoffeeGeek. No cross posting allowed - do not post your topic to more than one forum, nor repost a topic to the same forum. Who Can Read The Forum? Anyone can read posts in these discussion boards. Who Can Post New Topics? Any registered CoffeeGeek member can post new topics. Who Can Post Replies? Any registered CoffeeGeek member can post replies. Can Photos be posted? Anyone can post photos in their new topics or replies. Who can change or delete posts? Any CoffeeGeek member can edit their own posts. Only moderators can delete posts. Probationary Period: If you are a new signup for CoffeeGeek, you cannot promote, endorse, criticise or otherwise post an unsolicited endorsement for any company, product or service in your first five postings.