Use between 1/4 oz and 1/2 oz of syrup per 2 oz of bourbon. If you want one number, pour 1/3 oz, which is a 1:6 ratio and the setting that fixes most Old Fashioneds people complain about. Too sweet usually means someone free-poured. Too harsh usually means they skipped the syrup entirely and muddled a dry sugar cube that never dissolved. Measure it with a jigger, use something with body like Traditional Proof Syrup, and the drink comes into focus.
What makes a great Old Fashioned
The drink is bourbon, sugar, bitters, and water, and the sugar is the part nobody respects. In a spirit-forward cocktail the sweetener is a third of the recipe, and it does far more than sweeten. It carries the body, the texture across the tongue, and how long the drink lingers after you swallow.
This is where 1:1 simple syrup fails. It is roughly half water by weight, so a half ounce of it is a quarter ounce of actual sugar and a quarter ounce of, effectively, extra melt. Add that to the half ounce of water the ice already contributes and the drink thins out exactly at the finish. People taste that and assume they need more sugar. They need denser sugar.
The ratio table
All three assume 2 oz of bourbon at 90 to 100 proof and a thick raw cane syrup, not 1:1 simple.
- 1:8 — 1/4 oz syrup to 2 oz bourbon. Dry and spirit-forward. The sugar reads as texture more than sweetness. Best with barrel proof or high-rye bourbon, and best for people who normally drink whiskey neat.
- 1:6 — 1/3 oz syrup to 2 oz bourbon. The default, and the one to start at. Balanced enough that the bourbon still leads but the edges are rounded off. This is what most good bars are pouring.
- 1:4 — 1/2 oz syrup to 2 oz bourbon. Openly sweet, closer to the mid-century version of the drink. Best with a flavored syrup you actually want to taste, or with lower-proof bourbon that needs the help.
If you are using 1:1 simple syrup instead, add roughly fifty percent more volume to land in the same place, and accept a shorter finish.
The build at 1:6
Ingredients
- 2 oz bourbon or rye
- 1/3 oz Traditional Proof Syrup
- 2 dashes aromatic bitters
- Orange peel
Instructions
- Combine the bourbon, syrup, and bitters in a mixing glass filled with ice.
- Stir twenty to thirty seconds, until the glass frosts over and your fingers object.
- Taste with a straw before you strain. This is the moment to adjust, not after.
- Strain over one large cube in a rocks glass.
- Express the orange peel oil side down over the surface and drop it in.
Why the sweetener matters
Proof Syrup is made in small batches from raw cane sugar. Raw cane keeps a faint molasses note that reads as depth rather than sweetness, which is why a smaller pour of it does more work than a larger pour of white sugar syrup. It is thicker, so it gives the drink weight and a finish that holds instead of dropping off.
Consistency is the other half. A homemade batch changes as it reduces on the stove and thins in the fridge, so your 1:6 today is someone else's 1:5 next week. Ratios only mean something when the ingredient is stable. Bottles come in 8 oz, and there is a 12-bottle case if you make these often.
Adjusting the ratio for flavored syrups
Orange, at 1:6
Ingredients
- 2 oz bourbon
- 1/3 oz Orange Proof Syrup
- 2 dashes aromatic bitters
- Orange peel
Citrus reads as brightness rather than sugar, so this one holds its shape at the standard ratio. Skip any extra orange garnish beyond the peel.
Best for: summer, and anyone who orders their Old Fashioned with fruit in it.
Pecan, at 1:6
Ingredients
- 2 oz bourbon
- 1/3 oz Pecan Proof Syrup
- 2 dashes aromatic bitters
- Orange peel
Nut flavor gives the impression of sweetness without adding much, so the ratio stays put. Works especially well with wheated bourbon.
Best for: autumn, and converting people who say they do not like whiskey.
Maple Bacon, at 1:8
Ingredients
- 2 oz high-proof bourbon
- 1/4 oz Maple Bacon Proof Syrup
- 2 dashes aromatic bitters
- Orange peel
Maple carries more perceived sweetness than cane, and the savory note gets heavy fast. Pull the ratio back a step and let the smoke sit underneath.
Best for: cold nights, and drinks made in front of people who want to watch.
Getting the ratio right in practice
Dilution is part of the ratio
A properly stirred Old Fashioned gains roughly a half ounce of water, which is more volume than the syrup itself. Under-stir and the drink tastes both hot and sweet, since nothing has integrated. If your 1:6 seems cloying, stir ten seconds longer before you touch the sugar.
Adjust for proof, not for taste memory
An 80 proof bourbon at 1:4 turns to syrup water. A 115 proof bourbon at 1:8 is still plenty sweet. Set the ratio against the bottle in front of you rather than the number you used last time with something else.
Taste before the peel goes in
Citrus oil changes the read of the whole drink and can make an over-sweet cocktail seem balanced for about a minute. Judge the ratio on the stirred liquid alone, then garnish.
Batch it if you are making more than four
Scale the ratio, add twenty percent water to stand in for the stir, and chill the bottle. Pour over ice and garnish to order. Guests get the same drink and you get to stay in the room.
Start at 1:6 and move from there
Pour a third of an ounce, stir it properly, and taste before you adjust. Once the syrup is a fixed quantity instead of a guess, every other change you make actually tells you something. See the full lineup at the Proof Syrup collection, or go straight to the Old Fashioned syrups.
