Swapping duvets twice a year is a job most households put off, so the summer one stays on the bed into October and you lie there chilly for a fortnight before anybody fetches the winter one from the loft. The Woolroom Deluxe Washable 3-in-1 Wool Duvet, sold as the All Season, keeps both weights to hand so nobody has to. Woolroom sells it direct as two flat duvets of British wool in organic cotton covers, a lighter one and a medium one, with poppers round the edges so they fasten into a single heavy duvet for winter. It's the only duvet in the Deluxe Washable range that changes weight through the year, and it is the one I'd send you to if your bedroom gets properly cold. Climb into bed on a January night with both halves fastened and the weight is the first thing you notice, then a dry, even warmth without the sticky heat a polyester duvet builds overnight.
Three other Deluxe Washable weights sit beside it, and two of them match its halves. The Woolroom Deluxe Washable Light is one 200gsm duvet, the same weight as the summer half here, and my pick for hot sleepers. The Woolroom Deluxe Washable Medium is one 350gsm duvet, matching the heavier half, and it is the all-rounder for a heated bedroom that most people should buy. The Woolroom Deluxe Washable Warm is one 500gsm duvet with nothing to fasten, and I'd treat it as about a 10 tog: fine with the heating on, short in a cold room. Fasten the All Season's halves and you have 550gsm, more wool than the Warm and the heaviest duvet in the range. Woolroom's Classic range, the Woolroom Classic Wool Duvet in Medium and its sister weights, has no joinable version, which is the plain reason this one comes from the washable range.
This is the duvet for a bedroom that's warm in July and cold in January, for a house where the heating goes off overnight, and for you if you feel the cold and know a Warm wouldn't be enough. It comes with a catch. The poppers that join the halves can come apart in the night, and once a few let go the two duvets slide over each other and bunch up inside the cover, so you start the day pulling it out and squaring it up again. Plenty of owners never have the trouble, and enough do that I'd expect a bit of morning faff in the winter months. Look elsewhere if you want a duvet you never think about, if you like one thick enough to disappear under, or if you'd be changing the cover on a super king by yourself.
From spring to autumn you sleep under one half
Unpopper the halves when the evenings get light and sleep under the 200gsm one alone. Woolroom's figure for it is 2 to 5 tog, and on the bed it's a thin quilted layer that keeps the chill off your shoulders without trapping heat. Sweat on a warm night soaks into the wool fibres instead of hanging in the air under the cover, so the bed stays dry where a thin polyester duvet would leave you sticky. A synthetic duvet that leaves you clammy is the problem wool answers, and Woolroom is where I'd buy it. One owner tried both halves together on cooler days at the start of summer and called it "unbearably hot", then slept under a single layer all summer and found it "not too hot and very comfortable". Keep the heavier half in its bag until the nights turn cool.
Switch to the 350gsm half for the months in between. Woolroom rates it 7 to 10 tog, and in a heated house it carries on further into winter than you'd think: one owner says it was freezing outside and the heavier half on its own was still all they needed. So "3-in-1" means the Light half, the Medium half and the two fastened together. You own two duvets and use them three ways, and only the third way involves the poppers.
Winter is both halves fastened, and it is heavy
Popper the two together and you're under 550gsm of wool, which Woolroom rates at the equivalent of 11 to 15 tog against the Warm's 11 to 14. The extra 50gsm is why a cold bedroom belongs here: to my mind the Warm runs cooler than its number, and a room that drops into single figures overnight wants more than that. I like a heavy duvet all year because the weight helps me settle, and I can always stick a leg or an arm out if I get warm, so the fastened pair is close to my idea of a winter bed.
Lifting it is another matter. A single weighs about 3.1kg with both halves on and an emperor about 7.5kg, so shaking it out is an effort. On top of you it feels lighter than that, because the weight spreads flat from shoulder to foot. One owner sums it up as "quite heavy to lift but doesn't feel weighty on the body". Another found it "like two wool blankets from the days of old" and now sleeps under the Medium half with a light blanket of their own on top. And it can suit a couple who sleep at opposite temperatures: "I get cold when I sleep but my husband is a hot sweaty sleeper and we have both found it to be wonderful".
It is flat, too, and stiff with both halves fastened. You can't tuck it round you or fold a corner back the way you can with feather, and owners coming from feather and down notice that first. There's a limit to it, too. A few owners still put a blanket on top in winter, and one with both layers on is "still needing extra layers". If your bedroom is that cold, add a blanket or turn the radiator up a notch.
The poppers are the part to watch
Fasteners that let go are the complaint that keeps coming up with this duvet, and it is specific to this one, the only Deluxe Washable duvet that comes in two halves. On some duvets a few poppers are weak from new. When they come undone overnight the top half slides off the bottom one, the pair rucks up inside the cover, and you are back to taking it all out to line it up. One owner calls the poppers "not fit for purpose". Another, on a king, gave up and now sleeps under one half, because remaking the bed every morning was too much hassle. Others never have a problem: "No trouble with poppers," one says, and another finds the two sections "stay firmly together".
Test every popper the day it arrives. Fasten the halves on the bed, give each one a firm tug, and if any pull apart easily, ring Woolroom about it while you are still inside the sleep trial. Owners who kept a weak set have fixed it with a few stitches across each popper or by adding studs of their own, which works, though it is a repair you shouldn't have to make. One owner feels the poppers in bed too, "aware of them from time to time under my chin". A cover that fits snugly gives the halves less room to wander, so use the closest-fitting one you have.
None of that changes my answer for a cold bedroom. Buy it, and check those poppers before the first cover goes on.
Is it the best all-season duvet for summer and winter?
For a bedroom that changes with the seasons, it is the one I'd pick. Plenty of duvets sold as all season are one fixed weight all year: The Nectar Duvet, for one, is 10.5 tog and nothing else. That is a compromise at both ends, too warm in a heatwave and thin in a cold snap. Two weights that come apart suit a room that changes better than any one weight can, and wool breathes in a way polyester filling doesn't, so a muggy August night stays dry. Bought separately, the Woolroom Deluxe Washable Light and the Woolroom Deluxe Washable Medium give you the same two weights with no poppers, so what the All Season adds is the fastened winter setting in one buy.
Washing it means washing two duvets
Woolroom's washable wool is "bathed in a chlorine solution to smooth out the natural barbs you find in wool", and that treatment is what lets it go in a machine without felting. The instructions are a wool or delicate cycle at 40 degrees with wool detergent, a spin under 800rpm and a washing line, never the tumble dryer. I'd unpopper the halves and wash them one at a time: fastened together, a king weighs 5.6kg before it takes on any water. Mostly it won't need the machine at all. Air it on a dry day and keep a cover on it.
The half you aren't using goes back in the fabric bag with handles that the duvet arrives in, which one owner rightly reckoned would be "very useful for storing it away". Don't vacuum-pack it, because Woolroom says the duvet isn't suitable for that. Owners keep remarking that theirs arrived with no wool smell at all, one of them adding "Absolutely no sheep aroma".
Inside both halves is British wool, and the label lets you trace it to the farm. The duvet is made in the EU, though, and that has caught out owners who had taken the whole thing for British, so go in knowing. Both halves are covered in unbleached organic cotton percale, crisp and plain, and one owner finds it crackles: "rather like trying to sleep (or not) in a crisp packet". Measure your duvet covers too. A flat wool duvet fills a cover edge to edge. One owner of a super king sent theirs back because it came up larger than their covers, and another warns that changing the cover on that size "is a 2 man job literally".
What to buy instead
If this isn't your duvet, the alternatives sit next to it in the Deluxe Washable range. If the poppers put you off and your bedroom is heated, the Woolroom Deluxe Washable Medium covers most of the year on its own, with the Woolroom Deluxe Washable Light for summer if you run hot, and neither has a fastener to fail. If you'd rather one heavier duvet and the heating stays on at night, the Woolroom Deluxe Washable Warm costs less and has nothing to come apart. For a properly cold bedroom, nothing in the range carries as much wool as this one, so the All Season is still the buy.
