First of all, let's take a look at brew ratios and what it is. Simply put, the brew ratio is the relationship between the amount of dry coffee used (dose) and the amount of coffee extracted (yield). This relationship is usually expressed in a dose:yield fashion, so a ratio of 1:2 means that for every gram of dry coffee, we will extract two grams of espresso. If you haven't already, make sure you check out our post about the basic espresso recipe.
Secondly, get yourself a reliable weighing scale here. If you're not already incorporating weight into your coffee brewing routines, start now. We talked perviously about how using weight will improve your coffee consistency and extractions tremendously.
Now that we understand brew ratios and have got ourselves a good weighing scale, let's take a look at the 1:3 brew ratios.
1:3 Brew Ratios have been gaining popularity and naturally, since Compound Coffee Co. is all about pursuing greater coffee, we had to try it out ourselves to see if it was worth all the hype. Normally, a 1:1 Brew Ratio (Ristretto) gives you a coffee that tends to be a lot more viscous and has a heavier mouthfeel. This tighter brew ratio plays to the strengths of a darker-roasted, low-grown coffee that has chocolatey, caramel characteristics. What ristretto espresso lacks in clarity, it makes up for in body or mouthfeel. As brew ratios increases, from 1:1 to 1:2, 1:3, 1:4 or even higher, the clarity of the coffee increases, body and viscosity decrease, and more individual tasting notes of the coffee become evident and easier to pick out.
The first time we tried to pull a 1:3 Brew Ratio with our normal espresso roast, WE FAILED. The shot tasted chalky, had a very drying finish and astringent after taste and was frankly, just not very pleasant. We had to coarsen the grind all the way to the same size you would use for a regular drip coffee just to get it to taste good. At that point we were getting an Extraction Yield of 13.8% compared to our normal 21.8%! What was happening? Was it the way we pulled our shot? Was it the coffee? The roast? The grinder? Actually, it is all of those things. Because 1:3 brew ratios bring out more flavour clarity, what that means is that whatever flaws we have in our coffee brewing process is equally exposed and out there for everyone to taste. So what do we do?
Brew at 9 Bars of pressure.
At Compound Coffee Co. we have been brewing our espressos using 6 bars of pressure since over a year ago instead of the default 9 bars. Why?
Simply because it gives us better tasting coffee. The exraction percentages have been higher and the coffee have been sweeter and clearer. Here's some other people's experience using lower pump pressures:
Yet now we are telling you to do the opposite and go back to 9 bars? Why?
While we were pulling 1:3 Brew Ratios using 6 bars, our extraction percentages dropped all the way to 13.4% just to get it to taste good.
When we switched back to 9 bars, we were able to grind finer and push our extractions to 16.6% before we started getting some undesirable characteristics.
Don't use Pre-infusion.
If you are one of the lucky few to have an espresso machine that allows you to control the Pre-brew / Pre-infusion aspect of your Espresso Brewing, this is NOT the time to use it. Pre-infusion created more over-extraction tastes coming through in the cup as the hot water stays in contact with the puck longer which causes overextraction. This is because we are still using the default 93.3C temperature water. With heavier bitter notes and a drying finish. Ramping straight to 9 bars helped smooth out the flavours much more.
Use a lower brew Temperature.
Because of the additional amount of water being run through the espresso puck for 1:3 Brew Ratios, the average brew temperature of the coffee grinds is now much higher compared to the average brew temperature for a 1:2 espresso. This is the reason why pre-infusion actually made the coffee taste worse as the increased contact time with hot water during the pre-infusion phase actually brought the average brew temperature even higher, causing overextraction more easily. Especially if you use a Mythos One Grinder, the average temperature of the coffee grinds starts off at a higer temperature, making matters even worse.
Go back to brewing at 6 Bars of Pressure and pre-infusion.
What? Didn't we say to brew at 9 Bars? Why are we back at 6 Bars again? As some of the previous articles have mentioned, brewing at 6 bars creates less channeling as the water is not being forced through the puck as strongly. We can also afford a longer contact time with the hot water now from the decreased pressure because we followed Tip 3 and lowered our Brew Temperature. Therefore, the average brew temperature is not as high and we can afford to extract longer.
Use well-roasted Coffee.
As we mentioned earlier, pulling shots at 1:3 Brew Ratios or higher lends itself to increased flavour clarity within the coffee. This means that the delicious parts of the coffee are exemplified but it also means that any flaws or defects are equally magnified. Especially at higher extraction percentages where more of the coffee flavours get dissolved and exposed, any roasting flaws or defects show themselves more more obviously then a tighter brew ratio where is can be covered up through the strength and viscosity of the espresso.
Coffees that are darker roasted to the point where roast flavours (Ashy / Smoky / Burnt / Charred Flavours) are introduced or have common defects such as scorching or tipping will show themselves quite easily when pulling shots with higher brew ratios. Therefore, we recommend getting coffees that are either lighter roasted or medium roasted with no obvious oils rising to the surface of the bean. Coffee Beans that have obvious color differences within each bean are also signs of uneven roasting and will not lend itself well to higher brew ratios.
Since pulling the 1:3 Brew Ratios, it has exposed certain flaws within our own coffees roasted by Compound Coffee Co. that we have since corrected and improved. How did we improve and correct our roasting? Stay tuned as we will definitely post about our coffee roasting journey in the near future. You can also buy some well-roasted coffees here : http://compoundcoffee.com/home/14-public-access
Pulling 1:3 Brew Ratios take a bit of time and a lot of messing around with different variables. At the end of the day however, it will provide a coffee that has better flavour clarity and it will easily expose any flaws that you may have in your coffee. Is the coffee that you brew properly roasted? How about your barista skills? Are you able to brew a well-roasted coffee at 1:3 Brew Ratios? Let us know your thoughts and feel free to ask us any questions! Also if you like the content that we are giving out don't forget to subscribe and support us by buying some awesome coffee here!