What would make a perfect pour over technique?

I am asking about what needs to be eliminated to get flavour separation in pour overs, or what should one be aiming for to reduce unwanted bitterness or whatever masks the flavours? Should I pour slower? If I do multiple pours should I avoid splash while starting the flow? Is there anything that I should generally avoid?

Update: so I’ve asked Grok and the usefulness of the answer surprised me. Copying it below for those who are curious:

To achieve flavor separation in pour-over coffee—where distinct flavors like fruitiness, sweetness, or acidity stand out clearly—and reduce unwanted bitterness or muddiness that masks those flavors, it’s all about controlling extraction. Bitterness often comes from over-extraction (pulling too many harsh compounds from the coffee), while lack of clarity can result from under-extraction or uneven extraction. Here’s what you need to focus on eliminating or adjusting, along with some practical tips:

Things to Eliminate or Avoid

  1. Uneven Extraction

    • The biggest culprit in masking flavors is inconsistent water flow through the coffee bed. If some grounds are over-extracted (bitter) and others under-extracted (sour or weak), you get a muddled cup.
    • What to do: Ensure an even coffee bed. After adding grounds to the filter, gently shake or tap the brewer to level it. Avoid pouring water carelessly—focus on saturating all grounds evenly.

  2. Channeling

    • Water finding "paths of least resistance" through the coffee bed (instead of flowing uniformly) leads to uneven extraction. This can amplify bitterness or leave flavors dull.
    • What to avoid: High, aggressive pours that disturb the bed and create channels. Splashing water haphazardly when starting can also disrupt the grounds.
    • What to do: Pour gently and steadily, starting from the center and moving outward in slow circles. Keep the spout low to the coffee bed to minimize agitation.

  3. Over-Extraction

    • Extracting too long or with too fine a grind pulls out bitter, astringent compounds (like excess tannins). This overwhelms delicate flavors.
    • What to avoid: Letting water sit too long in the brewer (e.g., slow draining due to a clogged filter or overly fine grind).
    • What to do: Aim for a total brew time of 2.5–4 minutes (depending on brew size). If it’s dragging past 4–5 minutes, coarsen your grind or check your filter.

  4. Under-Extraction

    • Too coarse a grind or too fast a pour can leave flavors underdeveloped, making the coffee taste flat or sour instead of vibrant.
    • What to avoid: Rushing the pour or using inconsistent timing between multiple pours.
    • What to do: Slow down and ensure each pour has enough contact time with the grounds.

  5. Turbidity (Fine Particles)

    • Excess fines (tiny coffee particles) slipping through the filter can muddy the cup, masking clarity.
    • What to avoid: Using a grinder that produces lots of fines (cheap blade grinders are notorious for this).
    • What to do: Use a quality burr grinder for a consistent grind size. Rinse your filter with hot water before brewing to reduce paper taste and help it seal better against fines.

Should You Pour Slower?

  • Yes, to an extent. A slower, controlled pour helps maintain even extraction and prevents channeling, which aids flavor clarity. However, don’t go so slow that brew time drags excessively—balance is key.
  • Try this: Pour in pulses (e.g., 50–60g of water every 30–45 seconds) rather than one continuous stream. This gives you control and lets the coffee "breathe" between pours, enhancing extraction consistency.

Multiple Pours and Splash Control

  • Multiple pours: Yes, they’re great for flavor separation. They allow fresh water to interact with the grounds in stages, pulling out different compounds each time. Aim for 3–5 pours depending on dose (e.g., for 20g coffee, try 60g bloom + 3 pours of 80g each).
  • Avoid splash: When starting each pour, especially the bloom (first 30–45 seconds where you wet the grounds with 2–3x their weight in water), avoid aggressive splashing. It disturbs the bed and can lead to channeling. Start with a gentle trickle, then increase flow slightly once the grounds are saturated.

General Things to Avoid

  • Boiling Water: Water at 100°C (212°F) can scorch the grounds, amplifying bitterness. Aim for 195–205°F (90–96°C), just off the boil.
  • Inconsistent Grind Size: A mix of boulders and fines throws off extraction. Invest in a good grinder if you haven’t already.
  • Skipping the Bloom: The initial bloom releases CO2, preventing uneven saturation later. Skipping it can mute flavors. Use 2–3x the coffee weight in water and let it sit for 30–45 seconds.
  • Overcomplicating Ratios: Stick to a simple starting point like 1:16 (1g coffee to 16g water) and tweak from there based on taste.

Aiming for Clarity

  • Grind Size: Medium to medium-coarse (think table salt or coarse sand) works best for most pour-overs (e.g., V60, Chemex). Adjust based on taste—finer if it’s sour, coarser if it’s bitter.
  • Water Quality: Bad water = bad coffee. Use filtered water to avoid off-flavors from chlorine or minerals.
  • Taste Test: After brewing, sip and note what stands out. Muddy? Check grind or pouring. Bitter? Shorten brew time or coarsen grind. Sour? Extend contact time or go finer.

Experimentation is your friend here. Start with a baseline (e.g., 20g coffee, 320g water, medium grind, 3 pours over 3.5 minutes), then adjust one variable at a time—pour speed, grind, or water temp—until the flavors pop. You’ll know you’ve nailed it when you can taste the coffee’s origin notes (like citrus, berry, or chocolate) without a bitter veil. What’s your current setup and method? I can refine this further if you share!