How to Blend Spirits to Hit a Target ABV

Every distillation run produces spirit at a slightly different strength and with a slightly different character. Without blending, each bottle you produce will be inconsistent, different ABV, different flavour balance, different mouthfeel. Blending is the tool that solves this. It lets you combine batches with different strengths to hit a precise target, and it lets you smooth out variation in character across runs. Done well, it is what separates a one-off batch from a repeatable product.

Dilution vs. Blending, What Is the Difference?

Dilution means adding water to reduce ABV. You are combining spirit with a neutral liquid that contributes nothing but volume. It is the right tool when you have a single batch at a known strength and want to reach a specific bottling ABV.

Blending means combining two or more spirit batches, each with their own strength and character. The result is a new liquid whose ABV sits between the two, weighted by the volume of each. Blending is the right tool when you want to combine two batches, balance two different characters, or hit a target ABV without adding water.

In practice, most bottling involves both: blend your batches first, then dilute the blend to the final bottling strength. This is exactly what commercial distilleries do.

The Blending Formula

The calculation for blending two spirit batches to a target ABV uses what is known as the Pearson Square. It is straightforward algebra:

Volume of Spirit B is simply the remainder: V_B = V_total − V_A. The formula works regardless of which batch you call A or B, as long as Spirit A is the stronger of the two and the target ABV sits between them.

Blending Reference, Common Combinations

The table below shows how much of a high-strength batch (Spirit A) is needed per litre of final blend for common starting and target ABVs. Spirit B is assumed to be water or a 40% ABV spirit. See the notes column.

Why Blend Rather Than Just Dilute Each Batch Separately?

If you produce multiple runs of the same spirit, diluting each to bottling strength separately then bottling them is the easiest approach, but it gives you inconsistent bottles. Run 1 might be slightly richer, run 2 slightly lighter. Each bottle is technically correct in ABV but they taste different.

Blending before final dilution solves this. When you combine two runs into a single large batch, then dilute that combined batch to bottling strength, every bottle drawn from it is identical. This is the core reason commercial distilleries blend: not just to hit an ABV, but to achieve consistency.

The secondary reason is flavour correction. If run 1 has more tails character than you would like, blending it with a cleaner run 2 brings the overall character back into balance. If run 1 is slightly thin, run 2 can add body. You have much more control over the finished product as a blender than as a distiller alone.

Blending Batches with Different Characters

When combining batches that differ not just in strength but in character: for example, a rich, fruity run with a lighter, cleaner one, the process is called vatting. The goal is to use each batch's strengths to compensate for the other's weaknesses.

The practical method is to blend small samples in varying ratios first. Try 30/70, 50/50, and 70/30 splits at approximately your target ABV, then assess each sample after 24–48 hours of resting. Character blends often need time for the components to integrate, a blend that tastes harsh or disjointed immediately after mixing will frequently smooth out significantly after a few days.

Keep a record of your blend ratios. If a combination works well, you need to be able to reproduce it with the next batch.

Step-by-Step: Blending Two Batches

1. 1Measure both batches accurately. Take ABV readings with a calibrated alcoholmeter at 20°C. Record volume and ABV for each. These are your inputs for the blending formula.
2. 2Decide your target ABV and total volume. The target ABV must sit between the ABVs of the two batches. Your total volume is constrained by however much spirit you have available, the calculator will tell you if you have enough of each batch.
3. 3Calculate volumes using the Pearson Square or the blending calculator. Note the volumes down before you start pouring, it is easy to lose track mid-blend.
4. 4Blend a small sample first. Before committing to the full batch, blend 100 mL at the calculated ratio and assess it after 24 hours. Adjust if needed, a 5% shift in the ratio is easier to correct at sample scale than at full batch scale.
5. 5Blend the full batch. Pour the calculated volumes into a clean vessel. Stir gently, do not shake, which introduces oxygen unnecessarily. Measure the ABV of the blend to confirm it is at target.
6. 6Rest before final dilution and bottling. Allow the blend to rest for at least 24–48 hours. For character blends (two different spirit types), a week or more is better. Then dilute to final bottling strength using the ABV dilution calculator.

Common Mistakes to Avoid

• Blending without measuring ABV first. The formula only works if your input ABV readings are accurate. Always measure at 20°C with a calibrated alcoholmeter before blending.
• Skipping the sample blend. Blending 100 mL costs nothing and tells you whether the ratio needs adjusting before you commit the whole batch.
• Bottling immediately after blending. The blend needs time to integrate. Always rest before bottling, even 24 hours makes a difference.
• Trying to blend three batches at once. Do it iteratively, blend A and B first, measure the result, then blend that with C. Trying to hit a three-way target in a single step is harder to check and correct.
• Not keeping records. Write down the ABV, volume, and ratio of every blend. If you produce a bottle you love, you need to be able to reproduce it.

Frequently Asked Questions