Short answer: no, properly made borosilicate glass containers don't stain or hold onto smells the way plastic does, because glass has no microscopic gaps for pigment and odour molecules to hide in. Tomato sauce, turmeric and curry oils sit on the surface of glass and rinse away completely, whereas the same foods can work their way into a plastic tub and never fully wash out. The one thing worth knowing: on most glass meal prep sets, including ours, the lid is BPA-free plastic rather than glass, so it's the part that needs a little more care.
Why Plastic Stains and Smells But Glass Doesn't
Plastic containers are made from long polymer chains that pack together unevenly, leaving microscopic gaps that open and close as the material flexes. Oily, pigmented compounds — like the ones in tomato sauce or turmeric — can slip into those gaps and settle in deeper than a wash with soap and water can reach, which is why a plastic tub can look faintly orange for months after one batch of curry. Glass has a completely different structure: it's a rigid, fused network of silicon and oxygen with no gaps at all, so those same compounds simply sit on the surface and rinse off. As the science explainer site ScienceABC puts it, plastic's structure gives grease and pigment a pathway into the material, while glass offers none. That's the whole reason glass has stayed the go-to material for anything that stains hard — think Pyrex dishes that have survived decades of lasagne and tomato bakes without a mark on them.
What About the Lid? It's Still Worth a Little Care
The lids on glass meal prep containers, including our 10-Piece and 5-Piece sets, are BPA-free plastic with a silicone seal, not glass, because that's what makes the hinged locks and airtight seal possible. That means the lid can still pick up a bit of staining or smell from strong spices or tomato-based sauces over time, even though the glass base won't. The fix is simple: rinse the lid straight after use rather than leaving sauce to dry on, and hand-wash it rather than putting it through the dishwasher, which helps the silicone seal keep its grip for longer too. If a lid ever does stain or wear out, it's designed to be dealt with on its own — every Good For You container comes with a 2-year guarantee, so you can get a replacement part rather than throwing out the whole set.
How Long Can You Actually Keep Batch-Cooked Food Before It Needs Eating or Freezing?
Under UK Food Standards Agency guidance, cooked food should be cooled at room temperature and moved into the fridge within one to two hours, and any cooked leftovers should be eaten within 48 hours or frozen if that's not realistic — full detail is in the FSA's own guidance on chilling, freezing and defrosting food safely. Your fridge should sit between 0°C and 5°C and your freezer around -18°C. If you're doing a Sunday batch cook, splitting the food into smaller portions before it goes in the fridge helps it cool faster and more evenly, which matters more than the container material itself — though an airtight seal does help stop one dish's smell (or stain) transferring to whatever's stacked next to it. Once something's been frozen and properly defrosted, the FSA's guidance is to use it within 24 hours and only reheat it once.
Picking the Right Size for Your Kitchen
Container size matters as much as material once you're batch cooking regularly. Our 10-Piece Glass Meal Prep Set gives you five 1040ml containers for full dinners and five 370ml containers for snacks or sides, so a week of lunches and a week of small portions come in the same set. If you'd rather have one size across the board, the 5-Piece Glass Meal Prep Set uses 850ml containers, which suit hearty salads, pasta bakes or a main course with veg on the side. For packing a child's lunch, the Kids Meal Prep 6-Pack uses smaller 370ml containers sized for a school portion rather than an adult one — and because they're the same borosilicate glass, they won't hold onto the smell of yesterday's spaghetti either. All three are LFGB-certified, BPA-free, and safe in the oven, microwave, freezer and dishwasher (glass base only — hand-wash the lid as above).
Keeping Your Containers Looking Like New for Years
The glass base can go straight in the dishwasher, but wash the lid by hand to protect the silicone seal, and give both a rinse as soon as you're done eating rather than letting sauce sit and dry. Beyond that, there's not much maintenance involved — that's really the point of glass. If a lid or seal ever does wear out ahead of the glass itself, it's covered by the 2-year guarantee that comes with every set, so you're replacing one part rather than binning containers that are otherwise still perfectly good.
Frequently Asked Questions
Do glass meal prep containers really not stain, even with tomato sauce or turmeric?
Yes — the glass base itself won't stain because it has no microscopic gaps for pigment molecules to get into, unlike plastic. The BPA-free plastic lid can still pick up some staining over time, which is why it's worth rinsing it promptly and hand-washing it rather than staining the glass, which stays completely unaffected.
Why does plastic hold onto stains and smells when glass doesn't?
Plastic is made of polymer chains with microscopic gaps that let oily, pigmented compounds from food work their way into the material itself, beyond where washing can reach. Glass is a rigid, non-porous structure with no such gaps, so the same compounds just sit on the surface and rinse away completely.
Will the lid still stain or smell, since it's plastic?
It can, because the lid on a glass meal prep set is BPA-free plastic rather than glass, chosen so it can form the hinged locks and airtight seal. Rinsing it straight after use and hand-washing it rather than leaving sauce to dry on will keep it from staining as quickly.
How long can I keep batch-cooked meals in the fridge before I need to eat or freeze them?
UK Food Standards Agency guidance says cooked leftovers should be cooled and refrigerated within one to two hours, then eaten within 48 hours or frozen if that's not realistic. Your fridge should be kept between 0°C and 5°C for this to hold true.
Are glass meal prep containers dishwasher safe?
The glass base is dishwasher safe, but the plastic lid should be hand-washed to protect its silicone seal and keep it sealing tightly for longer. Washing the base and lid this way is what the manufacturer's care instructions recommend for Good For You's borosilicate glass sets.
What size glass container should I choose for an adult lunch versus a child's portion?
For an adult main meal, an 850ml or 1040ml container gives enough room for a full dinner with sides, while a 370ml container suits snacks or lighter portions. For a child's school lunch, a 370ml container sized for a smaller appetite, like the ones in a dedicated kids' set, tends to fit a lunchbox and a child's portion more sensibly than a full-size adult container.