Hopback!

It seems like for the last year, everything that we have done with hoppy beers has been working on decreasing bitterness while increasing overall hop flavor and aroma. I've probably stressed that point in hoppy beers more than anything else. When we introduced our Hopbursted IPA, it was really the beginning of a new (to us) process that we've used in every hoppy beer ever since. However, even when we put all of our hops in the kettle after we stop boiling, we still extract significant amounts of bitterness. In fact, a little over a year ago, we found out that our Pale Ale was getting about 45 IBU's just from our flameout hop addition after we sent our beers to a lab for analysis. After getting our results back, the way I began formulating recipes became much more exact with IBU calculations and it has helped us determine how we can cut back the bitterness levels.

As most of you know by now, we are changing the Weedy's Double IPA recipe. After brewing test batches at home, I realized that there would be no way for me to replicate the low amounts of bitterness I was getting on my 5 gallon system while getting all the hop aroma I was able to extract unless we changed some of our approach. We ended up getting a new hopback which is going to help out a lot. A hopback is really a pretty simple piece of equipment, but not one that is used very commonly. It is just a vessel that you fill with hops and run wort through before pumping the wort through the heat exchanger. With the hops being in contact with the hot wort for such a short amount of time, there is not time for the alpha acids to isomerize, so no bitterness is extracted. Instead, you are basically stripping the hops of their essential oils and capturing them in the wort. 

Since the hopback has a false bottom, it can be filled with whole leaf hops. Our equipment was set up to be used with pellets, but whole leaf hops can offer some substantial benefits. Since the hops never get hammered, they are never subject to heat or any other type of damage and you don't lose any of the hop matter. Another nice benefit from the brewery production side is that the whole leaf hops will act as a filter when trub starts to come out of the kettle. When we were brewing the Double IPA before, the amount of hops that went into it meant that we only would recover about 23 barrels of beer out of an anticipated 30 barrel batch. Now, we will be able to filter out some of the hop material and recover some additional wort, hopefully getting us up to 26-27 barrels of beer.

The biggest advantage though to using a hopback is the way the oils get extracted right before chilling. There are a lot of people that think that a hopback just provides the oils in the same way that dry hopping does, so they determine that a hopback isn't worth their time. That isn't truly the case. The since all the essential oils are in the wort for all of the active fermentation, they have the ability to undergo a process known as biotransformation. 

Biotransformation has turned into somewhat of a buzz word for a lot of brewers lately, but many brewers have yet to really learn what it is. The simple explanation is that yeast has the ability to take a compound (in this case, oils) and convert them into a different compound. The most common type of biotransformation is Geraniol into Beta-Citronella. Geraniol is a hop compound that is associated with floral flavors, sometimes even getting rose-like. Biotransormation can convert that compound into beta-Citronella which is very orange citrusy. Beers brewed with Citra (the hop that I have been frustrated with not being able to find), have proven to have a high amount of Citronella in them.

That has led to a lot of experimentation to find a way to maximize the flavors we desire from Citra, while using more readily available hops. Using hops high in Geraniol content (Cascade, Bravo, Apollo) therefore could potentially be used in a way that would allow us to get a Citra-like flavor. With the right yeast strain, it is possible that we could even create a more intensely aromatic Double IPA than would be possible with the yeast strain we were using before when we were using Citra. The yeast strain we have found has allowed us to take full advantage of biotransformation in a way that no other yeast strain I've seen is capable of doing.

Of course, the key to any good beer is to achieve some sort of balance of flavors. If the only flavor compound we got was Citronella, we wouldn't have a beer that resembles any type of hoppy flavor profile that we would enjoy. So the rest of the balancing act is getting flavors to compliment and balance the Citronella. In this case, some of the hops that we are using are high in Linalool. On its own, linalool has a distinctively fruity pebble flavor. With all the other flavor compounds though, it provides a sweet passion-fruit like flavor. When you combine those flavors along with the esters that our yeast strain provides (which have a very distinctive peach, mango, and tropical flavor), you can create a flavor profile unlike anything you will find from any hop with a neutral yeast strain.

Because of this biotransformation, it is actually pretty different to use a hopback than it is to just dry hop the beer. The great thing is that you can then dry hop during fermentation to take advantage of some other biotransformations, and follow that round of dry hops up with a second round of dry hopping post-fermentation in order to take advantage of the flavor compounds that were previously transformed and are then lost. This way, you can get a completely full range of flavors, taking advantage of 100% of the possible flavors from the hops. Using the whole leaf hops also means that all of the possible flavors haven't been lost or destroyed in the pelletizing process.

It is going to be a lot of fun getting this hopback installed and put to use!