Key takeaways

Roasted coffee bags typically run two to four layers: a printed outer layer, a barrier middle layer, and a food-safe inner layer.
Together, those layers usually measure 80 to 140 microns, which is enough to let the bag stand up, hold in aroma, and keep out outside air.
Thicker roasted coffee bags mean more protection and longer shelf life, but they also raise costs and reduce recyclability.

Roasted coffee bags matter for more than freshness alone. They also shape the pack’s appearance and usability. Exploring bag thickness is something roasters need to consider on many fronts and note for future development.

Chase Stafford is Director of Coffee at Iconik Coffee Roasters in Santa Fe, New Mexico, a roastery whose bags feature a clear window revealing the beans. He has worked through the trade-offs between protection, presentation, and sustainability first-hand. Read on for his insights.

What layers make up roasted coffee bags?

Three, in most cases. A printed outer layer carries the design, a barrier layer in the middle blocks light, oxygen, and moisture, and a food-safe inner layer sits against the beans.

Manufacturers craft the layers within a coffee bag to protect and preserve the roasted beans inside. That means an outer layer carrying the printed label, then a second protective layer that may include a metallic lining and a valve. A food-safe layer inside the bag then shields the beans from moisture.

Typically, roasters use two to four layers of lining to effectively maintain freshness. The number of layers can also depend on where the coffee is sold. For direct-to-consumer sales, a single laminate may be preferable. Selling to grocery chains may require additional layers to ensure freshness. Transport can damage bags, so more layers may help there too.

What are these layers made of? The outer layer may use paper, PET (polyethylene terephthalate), or matte plastic film. Digital printing controls the print quality of the outer layer, and the result varies depending on the material underneath.

The second protective layer of roasted coffee bags usually carries a metallic lining of aluminium foil mixed with materials like low-density polyethylene (LDPE). This protective layer keeps light out of the bag and protects the coffee from moisture and oxygen. Yet metallic lining is not exactly eco-friendly, and it may not suit sustainability-focused roasters, especially since coffee drinkers care deeply about the environment. Alternatives include metallised films or ethylene-vinyl alcohol copolymer (EVOH), which recycles more readily and costs less.

People making coffee at home may prefer a recyclable bag, and foil-lined bags typically do not suit the recycling bin.

The last layer usually consists of polyethylene (PE), a food-safe plastic that keeps the coffee protected from external threats. All three layers ensure seal integrity, which keeps outside air and moisture away and maintains freshness. Each additional layer adds durability.

Iconik Coffee Roasters made its window a deliberate part of that structure. “We chose a few key creative decisions that we wanted to see, such as the clear window that wraps around the front of our small bags and is added along the side of our 5lb bags,” Chase mentions. These bags are sensitive to sunlight, so they stay in a darker area of the café to prevent photodegradation.

That raises the question of roasted coffee bags’ thickness, and how thick is thick enough to keep the coffee fresh.

How thick should each layer of roasted coffee bags be?

Around 80 to 140 microns in total. That range lets the bag stand up on a shelf, hold the aroma in, and keep outside air out. Bag size and shipping conditions push the figure up or down.

Manufacturers measure the thickness of roasted coffee bags in microns, and by understanding grams per square metre (GSM). To measure it yourself, use a micrometer, or cut a sample and divide its weight by its area to reach GSM.

Some say the combined thickness of roasted coffee bags should sit between 80 and 140 microns. That allows a stand up pouch to hold its own shape, protect the aroma of the beans, and keep outside air out.

The size of roasted coffee bags also affects how thick the layers must be. A 1kg bag of beans weighs more than a 250g bag and needs to support the extra load. Format matters as well as volume, since a flat bottom bag carries weight differently from a pouch. Roasters may therefore alter their layers depending on how much coffee they want to sell in each bag.

If roasted coffee bags will ship, the layers may need to be thicker to protect the coffee from transport damage. Yet thicker layers with more puncture-resistant materials may increase costs and reduce recyclability.

Chase mentions that “the thickness of the coffee retail bags will skirt around porous bags. The thicker the bag, the more material, the less likely the bag allows for CO2 to escape,” which is why thicker layers preserve the coffee better and stop it going stale.

How do thickness choices affect freshness and sustainability?

Directly, and in opposite directions. Thicker layers extend shelf life but use more material and complicate recycling, so the right answer depends on where the coffee sells.

Most protective coffee bag layers contain compositions of plastic, which may not suit a roaster who prefers more eco-friendly packaging. To recycle coffee bags, consumers must take them apart and sort the materials properly.

More eco-friendly and compostable layers do exist, and MTPak Coffee offers them. The degassing valve does not change how many layers a coffee bag needs, since it simply lets the carbon dioxide building up inside escape.

Roasters must also consider shelf life and think about how long bags sit before anyone opens them. Thicker layers extend the shelf life of a coffee bag, which suits coffee sold in bulk at grocery stores.

Deciding on the layers of roasted coffee bags and their components depends on exactly what a roaster wants to do with their beans. A roaster growing from direct sales into online and grocery channels may want to invest in stronger, more durable bags. A roaster prioritising sustainability will need more sustainable materials such as low-density polyethylene (LDPE) and compostable linings like polylactic acid (PLA) structures.

Chase adds that “a majority of our coffees are flown to Iconik from Origin, vacuum sealed, frozen, thawed and roasted with precision tools; if the coffee goes stale on a shelf, we degrade the value and efforts from the farm level to the roastery… yet, if we can’t protect the earth, all of the above is for naught.” The challenge is to protect delicate coffee without harming the earth through too many plastics and materials.

If the bag fails to preserve the coffee well, consumers will blame the coffee rather than the bag. Protective, secure bags are therefore vital to the customer experience.

MTPak Coffee can assist with roasters’ bags at every level. From durability to sustainability, our range covers what roasters ask for, including recyclable and compostable bags alongside recyclable degassing valves.

There is a way to maintain quality while keeping the environment in mind. Not sure how thick your roasted coffee bags need to be? Put it to our team and we will spec it with you, micron by micron.

FAQs

How many layers does a roasted coffee bag need?
Two to four, depending on the sales channel. Direct-to-consumer coffee that moves quickly can work with fewer. Coffee heading into grocery chains, or travelling any distance, benefits from more layers to hold freshness and survive handling.

How thick should roasted coffee bags be in microns?
Between 80 and 140 microns across all layers is the usual range. That gives enough body for the bag to stand up, hold aroma in, and block outside air. Larger formats and shipped orders sit towards the upper end.

Does a degassing valve change the number of layers?
No. The valve sits within the barrier layer and simply releases the carbon dioxide that freshly roasted coffee gives off. It does not replace any layer, and it does not require an extra one.