Is there any risk of wort infection by not sanitizing hops before dry hopping?

2 Answers 2


There is an infection risk any time you open up your fermenter and especially when you throw stuff into it. If you dry hop at the right time you reduce that risk.

  • The alcohol built up protects against infection
  • The hops already in the beer act as a preservative
  • The pH is unfriendly to new growth
  • Most of the easy to eat sugars are already consumed

For these reasons, it is important to dry hop late in the fermentation. You need to allow alcohol and carbon dioxide to build up in solution to fight off invaders. Listen to the Dec 8, 2008 episode of Brew Strong for techniques and technicalities.

The same rules apply to many other fermentation additions. Other herbs and chips can be thrown right in. The more surface area the addition has - the more nooks & crannies - the larger risk of infection because there are more places for baddies to hide. I recommend soaking wood chips in alcohol of some sort, for example.


I've put hops for dry-hopping into a sterilized mesh bag (note* the bag was boiled in a pot of water and cooled with lid on to RT before adding the hops). I then squirt the outside of the bag with a squirt-bottle filled with grain alcohol. This kept things sterile and allowed for hop infusion without messy hop bits ending up in the final beer.

  • 2
    The squirting with alcohol is far from sterile my friend, but it probably helps a little with sanitation.
    – brewchez
    Commented Jan 19, 2010 at 13:34
  • v true...i'm a chemist, not a biologist...i still get those two mixed up. i do spray everything from equipment, surfaces, bottle necks, etc, with a 70% ethanol/water solution....have never had an infection.
    – Arlo427
    Commented Jan 19, 2010 at 15:56
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    This is a bad dry-hopping technique as it will boil off desirable hop aromas. It is the very volatile α-acids that yield wonderful hop smells. α-acids are not soluble in water, but they do dissolve in alcohol. This is why we boil to get hop flavor (and some aroma) and dry-hop to get aroma (and some flavor). Commented Jan 27, 2010 at 23:45
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    the bag is boiled and cooled prior to hop addition for sanitation
    – Arlo427
    Commented Jan 28, 2010 at 21:00
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    @Dean, Alpha acids (humulone, cohumulone, and adhumulone) are responsible for the bitterness hops impart to beer in a process called isomerization that occurs when you boil them. The the oils that impart aroma and flavor (which are indeed either evaporated or degraded when boiled) are composed of compounds to include Myrcene, Humulene, Caryophyllene, farnesene, and other hydrocarbons. So essentially, when you boil hops you create the bittering compounds, but lose the flavor/aroma compounds. (Source: Daniels, Ray, "Designing Great Beers," 1996, 2000)
    – Mike S
    Commented Nov 23, 2010 at 2:53

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