Should butter be kept refrigerated or left on the kitchen counter?

A US woman is on a crusade to change how the world eats butter, insisting that there is one thing many butter lovers are getting wrong.

Joelle Mertzel believes that butter should not be stored in the fridge and is going to some lengths to spread the word.

Mertzel is petitioning the US government to change their official advice, is selling butter dishes - and has even written a children’s book to convince others to follow her lead.

But is she right?

After years kept on the margins by margarine, butter has bounced back in popularity around the world in recent years, and publications in the UK and US have been eating up Mertzel’s claims.

While butter has arguably always been king here in New Zealand, the question of how best to store it has long been a talking point.

Fisher and Paykel’s decision to stop including a butter condition in its fridges sparked a one-man campaign by a Nelson butter enthusiast to restore the compartment.

“Real Kiwis use a butter conditioner,” Gary Black told the Herald in 2004.

“A butter conditioner is part of our culture.”

You’ll find Kiwis on both sides of the debate, with many older New Zealanders swearing by keeping at least some butter on the counter.

Mertzel, a 49-year-old mother of three, has gone to great lengths to prove that she is correct and has produced a website to promote her beliefs - much of which is dedicated to selling her custom-made butter dishes.

She has also written a children’s book telling her story, titled Change Your Life For The Butter.

She claims to have science on her side, claiming that “it is a scientific fact butter does not require refrigeration” and citing a test performed at an accredited food safety lab that showed that butter remained of a “good microbial quality” after 21 days.

She does not share whether anyone tasted the butter.

Homegrown advice

New Zealand’s own Westgold butter recommends taking a middle path to get the best out of your butter. In advice posted online, the West Coast firm admits that the issue is divisive but says “There’s nothing worse than preparing your toast in the morning and having to force cold butter down on your toast only to ruin it with your knife.”

Their advice?

“You can get the best of both worlds by keeping your butter refrigerated, but keep 1-2 days’ worth covered in a dish on the counter or in the pantry.”

This common sense approach to divvy up one’s butter in this way may explain why Mertzel’s crusade is finding easy fans in the US.

There, butter is often sold by the stick - around 113 grams worth or around a quarter of the size of our standard offering.

So by storing a stick on the kitchen counter, Americans may never have it exposed to the elements long enough to cause much damage.

Paul Schwarz, general manager of Food Safety and Quality Assurance for Fonterra, had similar advice - but said that keeping butter outside of the fridge was better for salted butter.

“We recommend always following the instructions on the label, in this case, keep your butter refrigerated and out of light. When it comes to salted butter, it’s not uncommon or unsafe to keep a small amount out of the fridge in a cool place, in an airtight container for a day or two, so it’s easy to use,” Schwarz said, also recommending a product such as Mainland Buttersoft, which can be spread straight from the fridge.

The Herald also sought official advice and asked New Zealand Food Safety acting deputy director-general Jenny Bishop the best way to keep our butter.

Her official advice was similar to that from the dairy industry, stating that your best course of action depends on whether your butter is salted or unsalted.

But she went further.

“Salted butter doesn’t need to be refrigerated because the salt prevents spoilage organisms from growing and the butter becoming rancid,” Bishop said.

“However, if the room temperature is consistently warmer than 21–25°C, the butter will lose its freshness after a couple of weeks (the higher the temperature, the shorter the time), but it will remain freshest if kept in the refrigerator.

“In contrast, unsalted, whipped or raw, unpasteurised butter is best kept in the fridge to minimize the chance of bacterial growth and rancidity.”

Happy spreading!

This article was first published in the NZ Herald and is republished here with permission.