Soak&Sleep New Zealand Mitchell Wool Mattress Topper reviewed

The Soak&Sleep New Zealand Mitchell Wool Mattress Topper is a slim, carded wool layer (2.5cm in the specification table) quilted into a 233 thread count unbleached cotton casing, sold in double, king and super king. It is designed to change the temperature of a bed more than its feel.

Specification

Everything in the table comes from the Soak&Sleep product page, which gives two different depths. Either way it is a thin layer: Soak&Sleep describes “a fine layer of supportive comfort” without a sinking feeling, so it will not soften a firm mattress the way a 5cm fibre or foam topper does.

What the evidence says about wool

Soak&Sleep’s page claims wool is “proven to improve your REM sleep quality by 25%” but does not name the study behind the figure, so we do not repeat it as fact. A peer-reviewed sleep-laboratory trial is more cautious: Shin et al. (2016), Nature and Science of Sleep, run by the University of Sydney with co-authors from the Woolmark Company, put 17 healthy young adults through nine nights of polysomnography. Wool sleepwear shortened the time taken to fall asleep, especially at 17°C, but the study found no effect of wool bedding on sleep. Wool does absorb and release moisture, and that is the property Soak&Sleep’s temperature claims rest on.

Because the fill is carded and quilted rather than loose, it stays evenly spread across the bed, though Soak&Sleep still advises shaking the topper out and rotating it once a week and using deep-fitting sheets and a protector over the top. Room temperature still matters more than any fill. The Sleep Charity recommends a bedroom of around 16 to 18°C and says temperatures above 24°C are likely to cause restlessness.

Prices by size

Prices were checked on soakandsleep.com in September 2026, with all three sizes in stock. There is no single or small double.

Care and guarantee

The page calls the topper machine washable in one paragraph but recommends a professional wash and dry about every six months in its care notes, followed by a patient cool tumble dry, because damp wool clumps. The five-year guarantee matches the goose down topper at the top of the range. There is no sleep trial; unused items can go back under the 365-day returns policy.