A visit to Witchmark distillery

After the excitement of Warminster Maltings it was on to Witchmark distillery. They're very whisky focussed, but being under three years old they don't have any to sell yet!

They have a mash tun from Northern Monk brewery and use locally grown Laureate malt in half tonne bags. It's malted at Warminster and milled at the distillery using a four roller mill. They do two brews a day, using a tonne of malt each. This gives them 100hl at 1.059-1.060. The local chalky water is treated by reverse osmosis to soften it. They mash Scotch whisky style, with three waters, the last of which is used for mashing the next brew.

Mash tun on left

As they have to wait three until they can sell their whisky they're very cautious. The use peracetic acid on the mash tun after use and do a weekly CIP. The plate heat exchanged is cleaned every day. 

Washbacks (fermenting vessels)

They have temperature control on their washbacks, with a maximum temperature of 30°C. Fermentation with WHC Hercules yeast takes 96 hours, which is long for whisky. The vessels are agitated at the beginning of fermentation to mix in the yeast, and at the end so the sediment is removed. Everything then goes to the wash still.  

Wash still

The wash still has a capacity of 5,000L, so two distillations are needed per washback. The wash is preheated from 30 to 70°C by a heat exchanger cooling the pot ale from 95°C. The wash at 8-8.5% ABV makes low wines at 30%. The low wines, as well as heads and tails from the spirit still go into the low wines tank. In terms of efficiency they get 800 litres of pure alcohol from two tonnes of malt. The 3,200L spirit still is pre-heated with water from the hot liquor tank, which is itself heated with water from the condensers. Gas from the green diesel industry is used to heat the distillations. 

The pot stills are out of balance, as five wash distillations need six spirit distillations. Spirit at 71-73% ABV is cut to 65% ABV for casking. Casks are ex-bourbon and Shaved, Toasted and Recharred wine casks. They have filled 1,000 barrels and have another 120 in tank. Production is currently 1,000 casks a year and they're aiming for 2,000 next year. The first few casks were stored dunnage style, on their side and three high, but most are palletised. 

Dunnage style cask storage

Bottling is done by hand, with one person able to doe 3-400 a day, though if they have four people working on it they can get up to 1000 done. 

Heads from the spirit still at 40% ABV can also be used in the column still to make Grain Neutral Spirit, six distillations make 1000L for the still. Typically they get 330L of GNS at 96.3% ABV. The two columns in the still each have 21 plates. Distillation takes at least 11 hours and can take up to 14.  The still has a vapour basket for when  making gin. Hardy botanicals go in the pot still, fluffy botanicals go in the vapour basket! 

For vodka a carbon filter, with three sections of carbon and silica sand is used. 

Long and narrow carbon filter

Then it was time for a tasting, though as I was driving only small sips!