Pellet vs. Leaf - Am I doing this right?

[Buttwidget]

About to use dried leaf hops for the first time in a recipe (LHBS was out of pellets).

I've heard people say to use 10% more hops when using leaf hops. I don't know that this is true and would like to find out what the Army says...

If I usually use 1 oz. of 6% AA pellet hops at a particular point in my boil, shouldn't I use 1 oz of 6% AA dry leaf hops? I thought it was about weight and AA %?

If I'm doing the calculations, my recipe calls for 1 oz of 6% AA pellet hops. The dry leaf hops I have are 6.8% AA. If I do the math I'm supposed to use .88 oz of the dry leaf hops (which is actually 10% less than the pellet amount) to ge the same AA effect.

I'm so confused!

~widget

[siwelwerd]

If I usually use 1 oz. of 6% AA pellet hops at a particular point in my boil, shouldn't I use 1 oz of 6% AA dry leaf hops? I thought it was about weight and AA %?

It's about weight, AA%, and utilization. Utilization measures the percentage of alpha acids present that are isomerized into iso-alpha acids.

The time spent in the boil is changing the utilization %. Many other things affect this as well--wort gravity, vigor of boil, total amount of hops, using a hop bag, hop form, etc. Pellets have increased utilization because the pelletizing process crushes the lupulin glands, leaving the alpha acids more exposed.

Designing Great Beers (Daniels) has a nice section listing all the things that can affect utilization.

[Buttwidget]

So if weight and AA% are equal between a sample of dry leaf and pellet hops, the answer is dependant on hop utilization.

If time, temp, boil vigor, gravity, etc. are the variables for hop utilization during the boil, then the difference between adding dry or pellet hops shouldn't have any effect on utilization. The boil is a constant.

Essentially you are saying to calculate weight and AA% when substituting hops no matter if they are dry leaf or pellets. No other adjustment required.

Right?

~widget

[BDawg]

If time, temp, boil vigor, gravity, etc. are the variables for hop utilization during the boil, then the difference between adding dry or pellet hops shouldn't have any effect on utilization. The boil is a constant.

No. You missed this sentence in Drew's reply:

Pellets have increased utilization because the pelletizing process crushes the lupulin glands, leaving the alpha acids more exposed.

As Drew said, the crushing process increases the utilization, too. That means that under the same wort conditions, pellets will yield more bitterness for the same weight and AA%. If you want the same bitterness, you need to use more whole hops. What you heard is correct, you need to increase the weight of whole hops by about 10%.

HTH-

[siwelwerd]

If time, temp, boil vigor, gravity, etc. are the variables for hop utilization during the boil, then the difference between adding dry or pellet hops shouldn't have any effect on utilization. The boil is a constant.

The key is the "etc."--you only listed ones that are related to the boil. The two main ones that are independent of boil/wort composition are the hop form, and how you are actually throwing them into the boil kettle. Packing a lot of hops into a small hop bag will decrease the utilization. Pelletizing increases the utilization. So with whole hops, you have to use about 10% more. If you cram a bag full of hops and drop it in, you'll likely need to use more as well.

[Buttwidget]

So we have to assume that they are being thrown into the boil in the same way to control that as a variable. I'm trying to get to the point at which just the type of hops used is the variable so I can understand what the difference is. Everything except the idea that the pelletization process causes the lupulin glands to be more "exposed" can be controlled for.

So, what I'm hearing is that the key difference between dry leaf hops and pelletized hops is that the pelletization of hops increases the utilization due to the "exposure" of the lupulin glands. I'm not trying to be disagreeable, but this doesn't compute to me.

The oils are extracted into the wort over time via heat, so any form of hops in the boil longer than 15 minutes should have no problem with oil extraction. Maybe later additions would see lower utilization, but don't those additions add fewer IBUs and more flavor and aroma characteristics? Thus the difference would be more subtle.

Like I said, I'm not trying to argue, but I really want to understand this and want to be sure I can reliably switch between dry leaf and pellet hops as required by my LHBS stock.

Thanks for taking the time to explain this.

~widget

[siwelwerd]

So, what I'm hearing is that the key difference between dry leaf hops and pelletized hops is that the pelletization of hops increases the utilization due to the "exposure" of the lupulin glands. I'm not trying to be disagreeable, but this doesn't compute to me.

If you accept that the vigor of the boil matters, then it seems to make perfect sense that crushing the lupulin glands will get the alpha acids more exposed to a (locally) more vigorous boil. Perhaps similar to how hop bags can limit utilization, just on a much smaller scale.

P.S. Daniels, Noonan, and Fix all have great books explaining the technical details of each step of the brewing process. They are great for answering questions like these. I highly recommend you read them all.

[Buttwidget]

I have Daniels and Noonan, looks like time for a re-read with an eye to this question.

The thing about the vigor of the boil, the boil is the same, its the hops being added that are different. While a boil's vigor may vary between batches, if we control for that we should be able to understand what the actual difference is between the type of hops bring used.

I still thank that you will extract oils from lupulin glands (exposed or not) in a 60-30 minute boil. That environment is too voilitile for some glands to be "hidden".

Thanks for the thoughts, I'll see what I can find and report back.

~widget