Tips & Techniques

Keep leftovers fresh with this fermentation pump

So long, bad leftovers.

words by: Natasha Marsh
Feb 26, 2022

In the span of a few weeks, I’ve gone from someone who hates eating leftovers, to someone who feels immense gratitude when I have leftovers in my fridge. In the past, I’d always wind up throwing uneaten food in the trash after a few days (even though I put them in the fridge with the best of intentions), but now that going to the grocery store poses so many risks, I’ve become pathological about eating every last morsel of food I’ve been lucky enough to have scrounged up.


My main complaint about leftovers has always been that things that were once crisp and crunchy (like vegetable ragout, the absolute best way to use up whatever you happen to have on hand that’s about to go bad), become soft and soggy just a few days later.


For years, I’ve been storing leftovers in widemouthed Mason jars with easy-to-screw-on plastic lids, as they are cheap, plentiful, and aesthetically pleasing. But I recently took leftover storage to a whole new level by using these lids meant for fermenting vegetables instead. They come with a clever handheld pump that sucks any extra air out of the jar.


Oxygen is the enemy when it comes to leftovers, as it makes food wilt, and go bad far more quickly. I’ve found that pumping as much air as possible out of my food containers keeps everything I store as snappy and fresh as the day I made it—up to a full week later. Even things that notoriously become mush overnight in the fridge, like broccoli, are al dente five days later.


The process to remove extra air from your leftovers is simple: Screw one of the air-lock-valve lids onto any widemouthed Mason jar, insert the hand-operated pump, and lift it upward anywhere from 2 to 5 times, pulling any extra air out of your jar. You’ll have pumped just about all the air you can out of your jar when the pump gets hard to pull up.


When it’s time to eat whatever you’ve vacuum sealed, press down on the air-lock valve in the center to release the pressure, then screw off your lid as you normally would. It feels like I’m performing a magic trick every time I open a jar and feel the vacuum seal popping.


The lids that come with this ultra-simple air-removing pump have a silicone ring to ensure a tighter seal and a handy date ring to remind you when you put the leftovers in the fridge to begin with. I’m hoping the one habit I can carry forward after this unprecedented time has passed us by is to be more mindful about wasting food. Having enough to eat (and the ability to stretch it out to last as long as I can) is the ultimate luxury.


You can grab an easy Mason jar fermenting lids and pump starter kit from Amazon for $23. If you’re looking to eat organic, check out these 3 delivery services.