How to Dry Hop

This article is a part of a series of articles to be published that relate directly to a part of the brewing process.  (repost from the original labeerfan.com blog - but I have made some modifications.  Its amazing how much your processes can change in just a few years.  Updated when to dry hop, free-ballin' and for how long)

One of my favorite processes when brewing is dry hopping.  It is really a great way to infuse some phenomenal, bright aroma into your beer.  As a home brewer its a good way to experiment with a single batch of beer to explore the different flavor and aroma characteristics you can impart into beer with different types of hops.  At the same time, its also really easy to negatively impact your beer.  If you aren't careful you may actually add contaminants to your beer, introduce too much oxygen, or ruin what is otherwise a really good beer!  Craft Breweries seem to have latched on to the term as a marketing gimmick for new beers.  I see a lot of “double dry hopped” comments or specific references to hop strains used in dry hopping.  Sometimes it is even mentioned when describing additions of non-traditional brewing ingredients, “dry hopped with cinnamon sticks” or something like that.  I think that is fine, and I understand using a term like dry hopping does invoke some sort of idea that this beer has had an extra process added to it that may distinguish it from other beers.  Its all marketing.

There are a ton of write-ups out there about dry hopping so I am going to go at this as a Q/A type session followed by an outline of my dry hop procedure.

Common Questions with the occasional lengthy answer:

1. What exactly is “dry-hopping”?

As I understand it dry hopping is when you add hops to your wort once it is cooled.  It is not specifically required to be an addition to the fermenter, but that is the most typical practice.  The idea behind dry hopping is that you are adding hops to cool wort rather than hot.  The essential element within a hop flower that adds aroma qualities to beer is the essential oils contained within the hop cone itself.  When boiled, these oils burn off over time and you lose their aromatic qualities.  This is why aroma hop additions are usually done towards the end of the boil rather than the beginning.  It is also why dry-hopping is seen as a way to impart a ton of aroma into a beer.  Dry hopping has also become a term for a process of brewing that doesnt necessarily relate directly to hops – its almost a term that just means “we added this ingredient to our beer post boil”.

2. When do I dry hop?

Hopefully part one of this answer was taken care of in answer #1, but to review, dry hopping is when you add hops to wort/beer post boil.  Primary Fermenter, Secondary Fermenter, Keg – whenever.  But now that you have decided to dry hop your beer, when during the post boil process is it BEST to add the dry hops?  For the purposes of this blog post I will answer this by describing when I add dry hops, but this topic is widely debated and my method is just what I have found to work best for my beers.  I highly recommend people try different approaches to all brewing practices, dry hopping is a perfect easy way to do this.  My approach to when to add dry-hops is based off of attenuation.  When you add hops to your beer you are adding one known quantity to your beer and an infinite amount of unknowns.  You know you are adding hops.  You don’t know what else is on/in those hops.  So my approach is to limit the effect that those unknowns could have on the beer, but my main focus is keeping oxygen out of my beer.  Nothing ruins a hoppy beer faster than oxygen.  Because of this (and because i purchased a large amount of them), I dry hop with pellets.  Hop pellets are chopped up hop cone matter that has been forced/squished down into small cylindrical pellets that look like green dog food.  While I know that there is still going to be oxygen introduced into my beer when I add pellets, my guess is that there is less oxygen in the pellets than there is in whole hop cone pellets.  So while I think that I have minimized the amount of oxygen that gets introduced when my pellets enter the beer, I know that there is still some in there.  I also know that yeast consume oxygen, so I like to add my dry hops when the beer is still fermenting (but not during vigorous fermentation) – so I add my first dry hop addition when the fermentation is approximately 90% through my expected attenuation and hope that the yeast will attack all of the oxygen they can get their hands on.  The good thing about adding @ 90% is there is usually very little activity so the amount of CO2 leaving the beer is pretty low and will not have a huge effect on the hops.  If you add your hops earlier in the ferment when there is still a lot of activity, its likely that that activity will mute out some of the aromas you are trying to get out of the hops.  I tried it once and it seemed like a waste of hops to add them during heavy fermentation.  

3. What amount of hops should I add to my beer?

The amount of hops you add is a very subjective question.  First you need to know what you are trying to make.  But for the sake of simplicity I will confine my answer to Pale Ale/IPA/IIPA for now.  

Here are my recommended guidelines for the amount of dry hops:

    • 10 – American Pale Ale / Amber Ale / Brown Ale – less than 2 oz of hops per 5/6 gallons of beer. 
    • 14A & B – American IPA and English IPA – less than 6 oz of hops per 5/6 gallons of beer.
    • 14C – Imperial India Pale Ale – less than 10 oz of hops per 5/6 gallons of beer.

Those are guidelines, and they are general.  You could go more, you could definitely use less.  Its up to you.  I recommend you split up a batch of beer into 5 1 gallon growlers.  Leave one growler as your control (no dry hops) and use an incremental amount in the other growlers.  Then do a blind tasting.  Trial and error.

4. I have spent a lot of time and effort to make sure that everything that has touched my wort has been free of contaminants, but what about the hops I am about to throw into my perfect fermenter of beer?  Do I need to sanitize them?

The short answer is no, you can add them as is – assuming you didn’t just dunk them into a bucket of lambic before you toss them into the beer.  Most hops that reach homebrewers have been handled fairly well.  You either buy your hops in bulk like i do where the hops are sealed with nitrogen and stored in a freezer, or you buy them online in smaller amounts that are in sealed containers, or maybe you just go over to your local home brew supply store and measure out your hops yourself.  Either way, as long as you didn’t spray them down with bacteria just before you dropped them into your beer they should be fine.  Hops do not provide a good environment for bacteria to live in (1).  If you add your hops to the fermenter when there is still activity (like I suggested in my answer to #2), there is probably enough activity to overwhelm the bacteria and like my (1) reference suggests, the PH is probably low enough to inhibit bacterial growth.

So feel free to add your hops to your beer without worrying about sanitizing them.  Its good practice to have a spray bottle of isopropyl alcohol handy when you are opening up your fermenters.  Spray down the outside of the fermenter while the airlock is still on the fermenter.  Cover that freaking thing.  I even spray down my hands.  Last week I was at my homebrew club’s Monster Brew at a local craft brewery and their brewers used sanitary gloves whenever they handled anything that could come in contact with the wort.  Another good practice that I follow is to spray some CO2 into the top of the fermenter while I add the dry hops.  Put a blanket of CO2 down on top of the beer, add the hops, keep adding CO2 to make sure that there is no oxygen in the fermenter and then close everything up.  You should be good to go.

5. How do you dry hop?  In a bag? Stainless mesh? Free-ballin’?

Below is my original posting.  Things have changed for me on this answer.  I used to use a bag, then I migrated to a stainless mesh container and now I am moving back to free ballin'.  My reasoning is this - the amount of aroma I have been getting lately pales in comparison to what others are achieving with shorter dry hop cycles and less hops.  Original post:

I like to dry hop in a nylon bag, but I am pretty sure I am going to start using a stainless mesh tea-ball or one of those dry hoppers from Stainless Brewing pretty soon.  I used to free ball, but there is no easy way to get the hops out of the fermenter if you free ball – this gives you much less control over your ingredients.  Here is my reasoning for wanting to get a stainless dry hopper or two.  First, I know you probably assume that its because stainless steel is cool.  And you are right, stainless steel is cool.  Reason #2 is this, if you dry hop in a nylon bag and you remove the bag from the wort it has usually expanded exponentially due to all of the beer that the hops soaked up.  Sometimes you have a large enough dry hop bill that the bag is bigger than the opening in your fermenter and you are left with the decision of cold crashing your wort while the hops are still in there and screwing up your recipe’s dry hop schedule, or you just yank the bag out hoping that the squeeze put on the hops isn't going to cause any off flavors or introduce too much oxygen.  Well it is going to do both, so option 1 is really the only option.  With a stainless dry hopper you get the cleaning convenience of stainless steel but you also have a rigid object which will not expand and contract like a nylon bag does.  I have never used one, but if I ever do I will post a report on this dry hop page with some more info.

A lot of people will tell you that you don't get as much hop aroma or hop contact with the wort when you confine the hops to a bag.  I don’t buy this at all and I think my beers are proof enough that this isn't true.  I will say this though, i do occasionally hook up CO2 to the bottom of my fermenter and push CO2 through the beer to try to stir up the hops.  I don't want to actually stir the container because that will more than likely oxygenate the beer which would essentially ruin it (or at least it would limit the shelf life).  Pushing CO2 from the bottom (through the spigot of a better bottle or through the bottom of a conical) is a perfect way to stir up the fermenter without introducing any O2.

But i think the bigger part of this answer to take away is that you need to think about your fermenter type.  When people start brewing they start out with a bucket or possibly a bucket and a glass carboy.  Plastic buckets are a terrible idea for fermenting – they let in way too much oxygen.  Glass is a fantastic thing to ferment in.  The problem with carboys is that the neck is really small, so you are left with limited options to on adding your dry hops.  I have a conical – which I know is a step way up from most homebrewers when you start out – but the great benefit to the conical is that you can dump stuff out of the bottom of it and in most cases the opening at the top is big enough that you could fit a dry hopper inside the container.  A good compromise is to ditch the annoying narrow neck glass carboy and go with the Big Mouth Bubbler from Northern Brewer.  I haven’t used it yet because I try to not use glass in the garage, but if I needed a new glass fermenter or if I was starting out this is the fermenter that I would recommend.  They advertise it as being easier to clean, which is a major bonus, but I would also be advertising its benefits for dry hop removal.  If they made it out of PET plastic like a better bottle and it had a spout at the bottom like a better bottle it would be the perfect homebrewer’s fermenter.  Stainless would probably make it too expensive, but that would be cool too.

But hey, that’s just me.  Now someone go invent one so I can buy some.

6. How long do I leave my hops in the fermenter?

This is different for everyone – I don't know that there is a correct answer for this as well.  For the first few years of brewing I dry hopped for 10 days.  For the next 4-5 years of brewing I dry hopped in 7 day increments.  My newest thing is to dry hop for 3 days (2).  My reasons are as follows:

    1. Firestone does it this way.  Buy the How to make a Pale Ale DVD from the Brewing Network and listen to Matt talk about dry hopping.  That should be enough, but in case it isn’t…
    2. I want shorter turn around time for fermenting beers and shorter contact time for hops with my wort/beer.  I want to get all of the bright aromatic portions of the hops and none of the grassy, vegetal components of them.
    3. I have seen zero drop off in hop aroma by shortening my dry hop schedule from 7 days to 3.  Why would I want to wait another 4 days?
    4. And finally, Firestone does it this way.

You really want the oils to come out of the hops and into your beer to get the hop aroma.  I have no science behind my theories, but I have to imagine that once you add something like a hop pellet to a liquid like fermented beer, the majority of the oils have to jump off of the hops relatively quickly into the beer – right?  I would dry hop for only one day if I thought it would be just as good as 3.  Its probably an experiment I should do (now that I am thinking/writing about it).  Again though, the key takeaway from this answer is you should have a planned length of time that the hops sit in the beer and you need to take them out.  Don’t just let the hops fall to the bottom and sit in your beer.  Have a plan of when to remove the hops and think about how you are going to do that.  

7. What temperature do you dry hop at?

I dry hop @ whatever temperature the beer is still fermenting at because I add the hops when fermentation is only 80% complete.  So that means that I usually dry hop when the beer is around 72-76F.  A few years back I remember talking to a brewer that said that he finished out fermentation and then dropped the temperature down to 64F to dry hop.  I tried that and it worked well, but it screwed up my whole oxygen removal by yeast method so I ditched that method.

8. What hops are the best ones to use?

The main determining factor in this is what style of beer you are making.  I’ve kind of kept this write-up american beer centric so far, so I will stick with that.  First off, if you are new to homebrewing and you have heard of the hop by name its probably suitable for dry-hopping.  Most of the boutique or popular hops that are out there right now are prized for their specific aromatic qualities.  Names like Simcoe, Citra, Amarillo, Nelson Sauvin, Mosaic, etc.  Those are the most popular.  But a better question is why are those hops special while other ones arent?  For one, most of those hops are relatively new and provide unique flavors that brewers havent been able to incorporate into a beer before.  By scientifically speaking it comes down to the essential hop oils which are: HumuleneMyrceneCaryophyllene, and Farnesene (4).  The one most people focus on is Myrcene, but I like to look at Farnesene too.  What I like to do is use this chart (3) and look at the hops I know have great pungent aroma.  Look at Citra and Simcoe, two of the most pungent of all of the hops.  It presents the oil composition of the hops so that you can see which oil makes up certain amounts of each hops oil composition.  In the case of both Citra and Simcoe they both are predominantly Myrcene and Farnesene – so when i notice that I look for other hops that have a similar oil composition.  Pacific Gem looks good, but the overall quantity of oils is substantially lower than Citra and Simcoe.  How about Newport?!  That looks interesting to me.  Its a fun way to choose.  But nothing works better than good old trial and error.  Try single hop dry hop additions of the same beer split over 5 growlers.  Or, try this cool method I have read about but never done myself of taking some cheap BMC beer and adding hops to the bottle for a cheap easy way to learn what different hops can provide.

The next step is to find out what hops work together well.  One of the most classic pairings of hops is Simcoe with Amarillo.  Pliny the Elder is the best example of this.  I like to use a combo of Columbus / Centennial together.  Layering your dry hops on top of each other in varying amounts is a good way to make unique aromas out of commonly used hops to make your beers different.

9. Can I use other ingredients than hops?

I mentioned earlier that some people use the term dry hopping as a descriptor for adding ingredients post boil even if there aren’t hops in the process.  I am not one of those people, but I understand why this is typical.  Just wait until you see your next label that says “Dry Hopped with Coffee”.  Frustrated?  How about when the guy/girl next to you sees the same beer and exclaims to there friend, “Hey! This beers dry hopped with coffee!  How cool is that?!”.  You can follow all of the guidelines I laid out above for any ingredient that you add post-boil but always keep in mind that you generally only know 1 part of what you are putting into your beer – the ingredient.  Maybe that ingredient is covered in bacteria?  Maybe its perfectly fine to add – but maybe its not.  The only ingredients that I have added to beer post boil at this point in my brewing hobby lifespan that I felt could be added straight out of the packaging is yeast, hops and coffee.  But yes you can add other ingredients using the same procedure.  Add spices, add coffee, add fruit, etc.  Just be smart about your amounts (dont ask me about when I dry hopped a wheat ale with 8 oz of lavender – disgusting and overwhelming) because with some ingredients a lot can go a long way.  Most spices can be overwhelming, so use a soft touch.  Use the multi growler method and try varying amounts before you go all in.  Other ingredients don’t pack a lot of wallop so you need to add aggressively – cocoa nibs in porters come to mind.  But then you need to think about the amount of flavor that the beer you are adding those ingredients to has.  Maybe 6oz of cocoa nibs in a 5 gallon batch of Russian Imperial stout seems a bit light when you taste it later, but the 6oz of cocoa nibs you added to your blonde ale sure seemed to go a long way.

My Dry Hopping Procedure

  1. Tie a length of solid fishing line to the top of your dry hop vessel (nylon bag or stainless dry hopper/tea bag) if the vessel doesnt already have something on it.  Make sure the line is long enough for the hops to be fully submerged.
  2. Sanitize your dry hop vessel by soaking it in sanitizing solution.  I use StarSan.
  3. Move your CO2 tank next to the fermenter and set the regulator to around 5 PSI.
  4. Let your vessel get reasonably dry (air dry).
  5. Measure out the hops in a sanitized bowl.  Glass or stainless steel bowl preferred.
  6. Add hops to dry hop vessel.
  7. Tie fishing line to something at the top of the fermenter that will make it easily retrievable once your dry hop cycle is complete.
  8. Spray down hands with isopropyl alcohol – or buy a box of medical gloves and then spray those suckers down (in case you don’t react well to the alcohol).
  9. Spray down the exterior of the fermenter opening, airlock and CO2 tube.
  10. Remove the air lock from the fermenter.  Place in sanitizing solution.
  11. Turn on the CO2 output into the top of the fermenter (where you will be adding your dry hops).
  12. Place the dry hop vessel in the fermenter.
  13. Let the CO2 run into the fermenter for a bit (10 seconds) just to purge the headspace.
  14. Remove the CO2 and replace the airlock.
  15. Spray down the exterior of the opening and the airlock with isopropyl.
  16. Repeat as necessary for multiple dry hop additions.  Make sure you clean and sanitize the dry hop vessel in between additions.

Dry hopping can be a lot of fun, but remember that dry hopping is not just an aroma contributor – you also get flavor from the hops when you add them to the fermenter.  This can be a really good thing – and it of course can be a really bad thing.  I once put a full pound of hops into a 5 gallon batch of IPA.  I had the hops and I wanted to know what that would do to a beer.  Plus I had another 5 gallons that could be used as a control to compare it against.  I definitely acheived the desired aroma for the beer – and then some – but what I also created was a very grassy flavors to the beer and it increased the hoppy flavors as well.  Everyone I poured it for said the beer that had the extra dry hop in it was too bitter.  Sometimes there is a perceived bitterness that people have when they are drinking a beer that is extra hoppy – even if those hops shouldn’t have added any hop bitterness to the beer.  So in the end the attitude should probably be that just because I can dry hop 5 gallons of beer with 1lb of hops, I probably shouldn’t.

Another thing to think about when dry hopping is that the aroma’s you achieve through dry hops will fall out over time.  Hoppy beers in general should be consumed quickly.  These are not beers for aging.  If you are looking to enter hoppy beers into competitions you need to think about the timing of your brew days – work backwards.  If the beers are due on the 30th of the month, count back how long it will take for you to bottle, carbonate, cold crash, dry hop, ferment and brew the beer.  Then continually taste your beers as you brew them and try and pay attention to what happens to the flavors and aromas of the beers as they age.  They definitely have a perfect phase of flavor conditioning.  With beers like Pale Ales this window is greater, but as the hopping and alcohol levels increase in your hop forward beers the window of flavor peaking will become smaller and smaller.  Hop aromas in beers with an ABV of above 7% fade quickly in my experience.  Thats why my IPA is around 6.5%

Here is an example recipe that you can follow to make a great dry-hopped American Pale Ale:

  • Batch Size – 6 gal
  • Target OG: 1.052
  • Target FG: 1.010
  • Target IBU: 30
  • Mash @ 150F for 60-90 Minutes
  • Ferment using WLP-001 starting @ 66F – let it free rise up to 72 over the next week.
  • Add dry hops @ 1.019

Fermentables

  • 80% – 2-Row
  • 10% – Light Munich Malt
  • 5% – Cara-Pils (a good full body on a Pale Ale that is dry hopped is a good idea)
  • 2.5% – Crystal 20 (go light with the crystal malt if you want your beer’s fresh aroma to last longer.  You also dont want to weigh down the beer with too much sweetness)
  • 2.5% – Crystal 40 (too much crystal can ruin a hoppy beer – especially one that uses hops that are high in Myrcene and Farnesene)

Hops

  • Magnum – 90 Min – 15 IBU (the majority of your bitterness should come from this addition)
  • Cascade – 30 Min – 10 IBU (flavor addition)
  • Cascade – 5 Min – 2.5 IBU
  • Columbus – 5 Min – 2.5 IBU
  • Dry Hop 1 (3 days) – .25 oz Columbus, .25 oz Centennial, .75 oz Citra, .75 oz Amarillo

References & Resources

(1) http://byo.com/stories/issue/item/569-dry-hopping-techniques

(2) http://morebeer.com/products/brewing-network-dvd-perfect-american-pale-ale.html

(3) http://canadianhomebrewsupplies.files.wordpress.com/2012/11/hop-chart.jpg

(4) http://beerlegends.com/hops