The strictest definition of beer is the Reinheitsgebot, the German beer purity law, states that beer can only include water, barley, and hops (Yeast wasn’t mentioned because its role was not well understood, but it was implied.) It turns out this simple recipe for beer contains a powerful antibacterial ingredient: hops.
The History of Hops in Beer
We have surviving beer recipes from nearly 4000 years ago, and we have chemical evidence that beer was produced as much as 7000 years ago, but the recipes were very different. The earliest beers involved the use of crumbled bread in water to make beer. There were no additives that preserved the beer, so it was likely drunk quickly.
By the time of the Egyptians, they likely used a very similar process to what we use today, with dedicated malting of barley, but they still didn’t have hops. Instead, they used emmer and sugary ingredients to help flavour their beer, although these didn’t have the preservative qualities of hops.
By the Middle Ages, people were flavouring their beer with gruit, a mixture of herbs that added bitterness and flavour to beer, but still lacked the preservative aspects. However, about this time, beer production began to increase in some places, which led to a desire to export beers (especially by monks, who could use it to fund their monasteries), and in order to do that, they needed a preservative. Hops were finally discovered and added to beer: the first mention of it occurs in 822 by a Carolingian monk.
This is only about 600 years before the Reinheitsgebot, and during the interim there was much conflict over whether it was proper to add hops to beer. In England, this debate was particularly heated, since the addition of hops to beer was associated with the invasion of William the Conqueror, who promoted a continental style of beer manufacturing. Over time, the delicious taste and preservative aspects of hops won out, even in England.
As beers began to be shipped over longer and longer distances, hops became an even more important ingredient. This is how the famous India pale ale (IPA) style started. More hops were added to beer to preserve it for the six-month-long, unrefrigerated trip from England to India (and Australia). Through the 1600s most beer shipped from England to the colonies of North America, with only a small portion going to Asia.
By 1775, about twice as much beer was being shipped to Asia as to North America, and the quantity would more than double by 1800 with increasing settlement in India and the founding of New South Wales and other Australian colonies. That England was able to ship so much beer to these distant lands was due to the increasing additions of hops and brewing it with stronger alcohol content, the characteristics we associated with an IPA, though this term wouldn’t be used for at least fifty and perhaps a hundred years after the invention of the style.
Antibacterial Properties of Hops
Because bacteria weren’t well understood until the 20th century, it wasn’t until 1937 that researchers discovered that hops preserved beer because they killed bacteria. At this time, it was shown that hop extracts could kill bacteria, but it wasn’t until 2008 that it was shown that hop extracts could actually have an impact on plaque formation.
Is There a Net Benefit?
But before you start adding an extra pint to your routine in the name of oral hygiene, we have to note that there’s no evidence that drinking beer has the net effect of decreasing gum disease or cavities. There are many reasons why beer might not be a net benefit for you:
- Although less acidic than wine, beer has a pH of 4, which can lead to erosion of your enamel
- Beer contains sugars and starches that feed oral bacteria
- Beer contains alcohol, which can dry out your mouth and irritate gums
However, if you’re going to be drinking beer anyway, you should consider choosing ones with a higher hop content, measured by the IBUs (international bitterness units). Most of the popular beers, like Victoria Bitter, XXXX Gold, or Toohey’s New, probably don’t have enough hops to make a difference. You’ll have to hunt around for something that will really make your taste buds stand up to have any chance of getting a benefit.