Our coffee science team clear up 3 myths & half-truths about the health benefits of cold brew coffee
What we’re not a fan of, is misinformation.
It turns out, when you combine health and the internet, you inevitably get a whole lot of nonsense. So, to help get the facts straight, we’ve compiled the current scientific evidence on the topic and condensed it into this bite sized summary
Almost all arguments talking up the health benefits of cold brew, focus on the lower acidity compared to hot brewed coffee. The logic goes:
- At lower temperatures, fatty acids are less soluble in water (true, see here for details warning: shameless self-promotion)
- Lower fatty acid content leads to more acidity (probably, would at least partially contribute)
- Acidity is bad for you (if coffee is bad for you, don’t eat strawberries)
Unfortunately, I haven’t seen any measurements done on pH by the proponents on acidity, but thankfully, there is some good stuff in the academic literature that can shed light on these claims.
What does Science have to Say?
1) Cold brew is only slightly less acidic than hot brew coffee
Yes, it turns out the pH of cold brew is only 16% less acidic than hot brew coffee, rather than the 60% quoted virtually everywhere.
To find the answers, we consulted the Scientific Communications journal under the Nature publishing group
Their numbers show that, on average, there is about 16% difference in total titrable acidity. In some cases, such as the Ethiopia Ardi and the Myanmar coffees, the pH was lower (i.e. more acidic) by about 60%. However, in Ethiopian Yirgacheffe and Colombian coffee was the same pH. For Brazil, hot coffee had a higher pH (i.e. less acidic). So, it seems that pH is more a function of origin, processing method (and possibly roast levels) than it is on the brew method.
(Side note: the solubility difference between the fatty acid Myristic acid at 100°C vs. 25°C is about 60%. This means that the total brew acidity is, perhaps, not solely dependent on fatty acid extraction.)
So, is cold brew less acidic? Yes, slightly by a factor of 16% on average. Will that make a difference to your gut health? I’m not a doctor (of medicine), but I’d imagine eating a strawberry may do worse for your bowel.
2) Cold Brew Coffee has less antioxidants than hot brewed coffee
Hot coffee, on average, holds a 20% higher antioxidant activity than its cold counterpart.
It’s also interesting that this roughly correlates to the proportional increase in solubility of radical scavenging fatty acids. Of course, antioxidant activity is not limited to these compounds alone, but it’s an interesting observation nonetheless.
Behold the graph below from the same source as above:
So is hot coffee is ‘better’ for you, in terms of radical scavenging/antioxidant potential.
3) If Cold Brew is better for gut health, it’s probably not due to lower acidity
It seems that it’s not the ‘lower acid content’ in cold brew that prevents irritation in the bowel – but the higher polysaccharide content.
A recent article looked at the biological effects of higher polysaccharide content present in cold brew coffee. This may explain the sweeter taste, and the impact it has on your gut health. It turns out, according to research by the Korean Department of Food Science and Biotechnology, the crude polysaccharide (sugar) extract in cold brew coffee stimulated the macrophage functions (i.e. pathogen/bad cell destroying cells in our bodies) in the intestinal system.
In simple terms, these supercells help fight disease in your gut.
Food for thought.
We say, drink the coffee you like because you enjoy it.
If you’re looking to drink cold brew coffee simply for the health benefits, there aren’t any big gains one way or the other.
Click here for more on the work of the Coffee Science & Education Centre
- N.Z. Rao And M. Fuller, 2018 (DOI:10.1038/s41598-018-34392-w).