This theory is a simplified version of a conversation I had with Alex Wallace (@wallacecoffee). For simplicities sake, I have broken it up into two parts - this first being about water levels, heat, and compensation from a OPPB recipe. It's meant to be used as a tool to help you dial in a coffee to highlight the exact flavours you want, and is based on techniques I found when I was training for Brewers Cup. I hope you enjoy and find it useful.

Let's start with a One Pour Post Bloom recipe (OPPB) - set up to your finest grind before encountering astringency and using the hottest water. What happens here is we're using the most amount of water and heat to extract flavour, the least amount of agitation, and the finest setting for your coffee. Having a fully filled cone means we're the maximum energy from our water to extract flavour, and bringing the most heat to extract flavour from our sweetest grind setting. For me, this establishes a coffees flavour potential, since everything is set 'to the max' and water is passing through coffee in a consistent way.(%)

At this point, we might find boiling ‘too hot’ (for whatever reason) and might find a slightly lower temperature compliments a coffee more. We also might find an extra gram or so gives us an ideal body for the coffee. If you arrive at any of these points, keep these in mind as part of your favourite 'maximum extraction’, and use them to determine your brewing ratio and your ‘maximum temperature’.

Having more water in the cone means having the most heat and energy, which extracts more flavour, particularly more of 'the good stuff' (TGS). My reference to this in this article is particularly in reference to sweetness, brightness and acidity. This is a useful thing to know, and I will come back to it later on.

So let’s say I taste it and I want to open up the body more, I’d want to pour at least one extra time. I’d start by grinding coarser. In relation to my OPPB, I’ve already established a ‘maximum output’ because I’ve found my finest point and set that to my hottest water. So to compensate for adding an extra pour I would grind coarser and most likely drop temp a little.

This is kind of my baseline for making changes. Change one thing, compensate to balance. Want to add an extra two pours? Grind coarser and/or drop the temp to balance. Of course we can also not compensate if we don't want to create balance - we could change pouring structure AND drop temp AND coarsen grind if we really want to soften acidty and body, or go the other way to turn up the flavours to the max. It’s up to you.(&)

Essentially when we change things from a OPPB recipe we change the way flavour is extracted. As per my last Explore the Pour we basically can choose what to extract when we're extracting. Flavour dilutes and changes over time, and we can use that to our advantage to choose how flavour comes through. A OPPB recipe at 99c is the 'standard' in a sense, as temperature is super high, water is super hot and we’re getting a good idea of how the coffee is gonna taste at its potential. It will be a nice balance of sweetness, acidity and all the rest because we're just using grind and heat quite efficiently. 

So any large introduction of water will boost the extraction efficiency of whatever point of the brew we’re at and create ‘the good stuff’ (TGS): positive acidity, sweetness, body and brightness. This is how I think about every coffee I brew - with a OPPB recipe as the standard, and thinking about what I can do to enhance favourable characteristics of the coffee.

One of our (Redbrick) Guatemalan coffees at the moment is chocolately, sweet and has a nice peach-like acidity. I could brew this at a low temperature to showcase acidity, but realistically the body is what I like the most about that coffee. So I would build a recipe around showcasing body - extra pours = extra body. But I would also want to highlight some acidity, so I would drop the temperature a little too. This way I'm highlighting the body and using temperature to create a more dynamic cup through controlling acidity.

That recipe might look like this: a 3x dose bloom, followed by 3 equal pours at 93c. This way we’re creating body through pours, controlling acidity through temperature and finding a ‘sweet spot’ with our grind, looking for astringency and the sweetest point. When we pour in even amounts, we extract coffee in the same way each time on a ‘starts strong, sour and bitter and becomes weaker, lighter and sweeter’ spectrum.

Now I mentioned before about ‘TGS’ coming through when a cone is higher. When we introduce lots of heat and energy into a dripper, the water can extract more efficiently at whichever point in the brewing cycle it is introduced. Kettle temperature plays a big part here: with higher temperatures from the kettle we find more sweetness and body, which in turn reduces the perceived acidity because it becomes balanced with the enhanced sweetness and body. So when we are extracting less, we are extracting less sweetness and body through temperature, which allows the acidity to shine.

If you did a recipe that was 12g:200g, with a 30g bloom then 1 pour of 170, one at 99c and one at 90c, the 99c would taste sweeter, have more body and be more balanced. the 90c would taste thinner, less body, more acidity because the lower temperature is creating less sweetness. Again, the hotter recipe extracts more, extracts better, and creates more sweetness. The cooler recipe extracts less, creates less sweetness and body, meaning we encounter more acidity.

Now we can take this and say 'ok, if i wanted the acidity i got from that 90c brew, but i wanted to relatively boost the extraction, then i could add more pours to extract some more, create more body and sweetness through the extra pours, and compensate still with a slightly coarser grind'. Your extraction may be ‘lower’, but you're compensating by creating more body and increasing extraction. So you may not reach that same 'maximum' extraction, but that's fine, because if you want more acidity a lower temp will do that. Likewise if you want a softer flavour, or a flavour with less sweetness - just go for a coarser grind and cop the lower extraction. Extraction% is just a flavour, and for me is the compass on a road map we can use to find the coffee that WE want to drink.

When pulse pouring I like to only introduce fresh water - which is why I tend to use slightly coarser settings. I find the flavour more clean and vibrant, and my theory is that fresh water is more soluble, so we can actually more efficently extract flavour, and I have noticed that we can even see an uptick in extraction at coarser grinds depending on the coffee and the amount of pulses (but that’s another story).

My other idea here is greater pour volume = greater acidity (or TGS). The higher the volume, the more positive acidity and sweetness (TGS) that comes with a better extraction. There’s lots of ways to create body, sweetness and acidity. It’s useful here to think of pour amounts as body, and temperature as acidity/sweetness. The point here is if you want a bright juicy and clean cup, choose a recipe that uses greater water volumes. If you want less body, choose a recipe that uses less pours.

Let’s tie this in with our spectrum I mentioned earlier: if we poured a 40g bloom, then pour 80, 50, 50 for example, then we are extracting more from the early acidic, sour, bitter and body-making flavours from that earlier point in the brewing cycle, and using the latter two pours to enhance body (since they will extract ‘less’ from the lower water level, but create body through agitation).

If we compare that recipe to something like 40, 60, 60, 60 we’ll find with the latter the flavours will be more balanced because we’re extracting flavour from 3 different points in the same way since each pour is bringing the same amount of extracting energy to the dripper. If we switched to 40, 50, 50, 80, then you will find more acidity/brightness from the END of the brewing cycle, where the flavour is more diluted. So earlier + more water = more bitter sour body-making compounds, later + more water = more sweet, light flavours from when the brewing cycle is nearly done. The difference in flavour will be - we’ve extracted more from the body-making part of the brew with 40 80 50 50 vs more from the lighter, brighter, sweeter part of the brew with 40 50 50 80.

There’s no right or wrong here, but we can use a recipe that uses a higher water volume at points that are earlier in the brew to showcase some more body, and a recipe that uses more water later in the brew to highlight some more clarity, a lighter body and possibly more brightness. The difference between a recipe that is a bloom then 2 equal pours and a bloom then 3 equal pours is the 3 equal pours will have more body and sweetness and the 2 equal pours will have a lighter body and more acidity.

There are lots of ways to develop sweetness and acidity in coffee, some just happen in different ways and achieve slightly different results. This is based on my experience over the last 2 years, particularly over the past 12 months where I only focused on flavour quality and effects of changing variables on a coffee. I hope this helps you build a roadmap to finding the flavours you want to drink in a coffee.

Tune in soon for part 2, where I wrap things up more and talk about blooming!

Let’s recap:

Hotter - more extraction, more body, more sweetness

Cooler - less extraction, less body, less sweetness - and in the deficit comes acidity

Less pours - thinner body from less agitation, but more heat in the cone so a closer flavour that comes from just the effect of temperature

More pours - more body AND extraction from agitation, but less heat in the cone so acidity has less of a chance to develop

Pouring high volumes introduces acidity and ‘The Good Stuff’ in whichever stage of the brewing cycle we’re at.

Earlier in the brewing cycle we have more body-making, sour, bitter flavours present.

Later in the brewing cycle we have more brightness, lighter flavours and sweetness present.

Our dose/ratio/coffee to water amount will determine the body.

% Coarser grinds in this context are ‘less extraction’, but coarser grinds can lead to greater cup clarity and can aid saturation.

& For me, a fine grind with lots of agitation and a super hot temp will most likely taste unbalanced, strong and probably a little astringent (thanks to saturation and channeling) - but with a perfectly roasted coffee I’ve had some very favourable cups.