Buffalo Trace Distillery has rolled out four different wheated recipe bourbons under its Experimental Collection to investigate the effect of entry proof on the whisky.

Different distillers have different opinions about effect of entry proof on the whisky.

Some think high entry proof makes for a better bourbon, while others are of the opinion that low entry proof will result in a more mellow, consistent finish.

The experiments resulted in all the four blends coming off the still at a constant 130 proof, though put into barrel for aging at four different entry proofs.

All the barrels were aged together for 11 years and seven months, and were bottled at 90 proof.

The four experimental bourbons were Wheat 125, 115, 105 and 90.

The Wheat 125 bourbon was the highest entry proof used in the experiment that resulted in high evaporation rate of 71% and released tastes of cooked berries, sweet honey and hints of spicy cloves and pepper.

The 115 entry proof resulted in high evaporation rate of 73% and offered sweet and fruity tastes with buttery toffee notes to the bourbon.

The 105 and 90 entry proof resulted in evaporation rates of 62% and 64% respectively.

Kentucky Bourbon Distillery master distiller Harlen Wheatley said this was an interesting experiment for them to conduct, and by keeping all of the variables consistent such as the proof off the still, aging time and placement next to each other in the warehouse, they were able to focus just on the entry proof into the barrel and see how it affected taste and evaporation rate.

"We were pleased that what we consider the ideal entry proof for a wheated bourbon, at 114 proof, was pretty close in proof to what we evaluated to also taste the best in this experiment – which was the 115 proof experiment," Wheatley added.

"It was gratifying to see that we have been on the right track this whole time with our entry proof for our wheated recipe bourbons. Another point of interest is the higher entry proofs, the higher the evaporation rates, which is something we’ve always suspected but now know for a fact."

The Experimental Collection will be packed in 375ml bottles and as 12 bottles in a case, with three bottles of each entry proof in a case.

The whiskies will retail for approximately $46.35 each.