Review: Mammut Meron IN Hooded Down Jacket

Down Jacket
Mammut Meron IN Hooded Down Jacket
$479, 14 oz.397g (men’s medium)
Sizes: men’s S-XXL, women’s XS-XL

As gray clouds hovered low overhead, the air still carried the dampness of the day’s rain, and a chilly wind whipped through our campsite by a lake in the Wind River Range, I zipped inside the Mammut Meron IN Hooded Down Jacket, pulled the hood up—and felt warmth immediately surround me. Fat but exceptionally light and packable, this puffy vaulted to the top of my list of insulated jackets. Here’s why.

I found the Meron more than warm enough on cool, wet, and windy evenings and mornings around 40° F in camps on an August backpacking trip in Wyoming’s Wind River Range. I also wore the Meron IN Hooded Down Jacket in similar temps backpacking five days through Washington’s Pasayten Wilderness in September, with mostly dry weather but one cool, damp morning of light rain, and found I didn’t always even pull the hood over my head (I also wore a wool hat).

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The Mammut Meron IN Hooded Down Jacket.
Testing the Mammut Meron IN Hooded Down Jacket in the Pasayten Wilderness.

At 14 ounces, for someone who doesn’t get cold too easily, this puffy jacket would deliver enough warmth (over one or two base layers) for temps around freezing; people who do get chilled easily may find it warm enough for 40° F and good over a lighter insulation layer in freezing temps.

Stuffed with RDS (Responsible Down Standard)-certified, 95 percent 900-fill-power goose down and five percent goose feather filling, the Meron boasts a warmth-to-weight ratio matched by very few down jackets. The sewnthrough construction, which stitches the outer, shell fabric to the inner, liner fabric—common in ultralight jackets made for three-season temperatures to reduce a jacket’s weight—creates visible boxes of down with potential cold spots at seams between them. But I noticed no compromise in warmth even on damp, windy evenings and mornings in camp.

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The helmet-compatible hood adjusts with a single drawcord in the back and wraps completely around your face, shielding it from wind; and with the zipper extending up over your chin, it seals in warmth very effectively, as do the elasticized cuffs and adjustable hem.

The fit leaves room for a couple of base layers and/or a light insulation piece underneath, yet never feels bulky. The length extends slightly below the waist, providing adequate coverage while helping to minimize weight. Two warm, zippered hand pockets are positioned higher than a backpack or climbing harness belt and are quite spacious: Each can fit a climbing skin (for backcountry skiing) plus a warm glove. The jacket stuffs into a zippered inside pocket, packing down to the size of a small bread loaf.

The lightweight, polyamide ripstop shell has a PFC-free DWR (durable, water-repellent treatment) that repelled a light rain in camp and sports durability comparable to the fabric on many lightweight down jackets. Plus, the jacket carries a Bluesign rating, indicating that at least 90 percent of the materials used in making it meet Bluesign standards.

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The Verdict

With exceptional warmth per ounce and packability and a total weight of just 14 ounces, the Mammut Meron IN Hooded DownJacket ranks among the very best down jackets for three-season backpacking and front-country camping in temperatures plunging to freezing.


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Whether you’re a beginner or seasoned backpacker, you’ll learn new tricks for making all of your trips go better in my “12 Expert Tips for Planning a Backpacking Trip,” A Practical Guide to Lightweight and Ultralight Backpacking,” and “How to Know How Hard a Hike Will Be.” With a paid subscription to The Big Outside, you can read all of those three stories for free; if you don’t have a subscription, you can download the e-guide versions of “12 Expert Tips for Planning a Backpacking Trip,” the lightweight and ultralight backpacking guide, and “How to Know How Hard a Hike Will Be.”

NOTE: I tested gear for Backpacker magazine for 20 years. At The Big Outside, I review only what I consider the best outdoor gear and apparel. See The Big Outside’s Gear Reviews page for categorized menus of gear reviews and expert buying tips.

—Michael Lanza

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Leave a Comment

4 thoughts on “Review: Mammut Meron IN Hooded Down Jacket”

  1. WHy is there no chest pocket with a zipper. It makes it a great place for phone. I have an old Mammut but the zippers are going out of it. I truly love this jacket. Do you know of any Mammut that has an outside pocket with zipper?

    • Hi Ray,

      Yes, the lack of a chest pocket is conspicuous. Pockets are sometimes eliminated to reduce its overall weight (the zipper weight). I have not looked through Mammut’s entire line to see which jackets have a chest pocket.

  2. Thank you for your review!

    I was curious about your comment about the helmet-compatible hood “…with the zipper extending up over your chin, it seals in warmth very effectively”. The photos of the young man wearing the jacket shows a large gap between the top of the zipper and his chin, but the jacket also seems over-sized on him. The photo of you wearing the jacket appears that the zipper fits more closely to the chin.

    I’m asking this question because I just returned a Patagonia Fitzroy jacket due to the poor hood design and gaps around the neck along with their poorly designed one-pull drawcord.

    Does the zipper and hood design on this jacket provide a secure and comfortable seal around the face to hold in body heat?

    Thanks for your help!

    • Hi Kerry,

      Thanks for that question, it’s a good one and I can see how the photos in this review might raise that question. In the photos of my son wearing the jacket, he has his hands in the pockets pushing downward a bit, which probably pulls the chin portion of the hood off his chin. I think he also didn’t snug the hood up more closely. Plus, he’s about three inches taller than me (I’m 5’8″ and that’s a men’s medium jacket). I deliberately snugged up the hood when wearing it in cold temps and found it’s adjustability created a nice seal around my head and face.

      I hope that helps. Good luck.