Hops drying formulas?

[mthompson]

I know how to do the precise dry matter method and then back calculate with a second known sample of hops as they are drying. A good write up can be found at Gorst Valley Hops (All Hopped Up; Sept-Oct 2009). But, this seems like a lot of work for the 2 or 3 pounds I am expecting, plus my scale ran out of batteries a soon is I got a total initial weight and it's 20 min. to the store (or about $6 in gas round trip).

Just curious what other methods or formulas other people are using. Any general rule such as '20-25% initial weight' that you guys are finding?

 

[BBL_Brewer]

I don't pay any attention to the weight. I dry mine until the strig (stem inside the cone) snaps when bent. That's really all there is to it.

 

[brian2can]

I just do wet weight x .20 = dry weight should be. so 30 oz wet x .20 = 6 oz dry

 

[day_trippr]

I just do wet weight x .20 = dry weight should be. so 30 oz wet x .20 = 6 oz dry

+1 this first harvest year at least (I'm a total hop-growing noob ) I weighed the cones right after I picked 'em and then dried them until they hit 20-25% of the green weight...

Cheers!

 

[Retrofit]

The general rule is 20%. Like bbl I try to break the stig. It's recieved sone jokes, but I pat my hops. There is a window where the edges are dry but the center is not and you can easily feel the center is soft and still damp. When I place my hand on my hops and they feel uniformly dry, they typically are. Break a hop cone see what happens to the stig, time to bag and seal.

 

[GVH_Dan]

As the author of the aforementioned article...thanks! Now, here's a copied post that gives the homebrewer's version:

OK, here's the long version of moisture measurement. It originates from a newsletter article I did a couple years ago...http://www.gorstvalleyhops.com/uploads/September_newsletter.pdf

The basic equation for determining moisture content of anything (hops, hay, herbs, etc.) is:

M% = ((Ww x Wd)/ Ww) x 100

M% = moisture content(%)
Ww = wet weight of the sample
Wd = weight of the sample after drying​

If you want to know the moisture content, take a small sample and weigh it to get Wet Weight (Ww). Then get the moisture out. Either bake it or put it in a microwave with some desiccant material to pull out the moisture. When you are sure it is completely dry, that is your Dry Weight (Wd). Now plug it in to see your starting moisture content.

I wouldn't use that sample in your beer, though. Especially if you used the microwave because most desiccants aren't food grade.

The problem for the homegrower is that you would need most of your crop to get an accurate enough reading of the moisture content. So it is somewhat pointless.

Instead, let's assume the starting moisture content is 80%. (I have seen from 93% when picked in the rain down to 74% for some smaller cones. So 80% is pretty much the middle.).

Let's pretend we have a 1/2 of a pound of cascade that we picked out of the backyard. Since we are assuming that it starts at 80%, we can use the above formula to calculate the Dry Weight....0.1 pounds.

Now let's say we want to dry down to a final moisture content of 10%. (Commercially, we shoot for 8%, but 10% is fine since you aren't pelletizing.) with a moisture content of 10% and a Dry Weight of 0.1 pounds, the "Wet Weight", which in this case is the weight of the dried hops, would be 0.111 pounds.

Working that out, the ratio of beginning to end weight is 0.111/0.5 = .222 or another way to say it is that the final weight of the hops is somewhere between 1/4 and 1/5 the starting weight.

One other side note, I've found that at 8% the stig still has a little give. Its not supple but it doesn't quite snap. It doesn't become brittle until 6%. At that point you are dangerously close to turning your cones into a pile of dust.

 

[mthompson]

Thanks for all the responses.

I will just get them down to 20% and call it good. I am trying to not get too technical with this....as I usually do. I just want to make sure they are close to commercial weights for recipe formulation.



Dan, I want to thank you for all the info and newsletters. I also have a friend that is thinking about getting into commercial hops production up here in Sheboygan County. He (and his wife) have lots of land and time.....and they started three varieties this year. I will direct them to your sight for more info.

 

[BBL_Brewer]

FYI, just because they at commercial weight doesn't mean that they are at commercial Alpha Acid content. Recipe formulation will still be somewhat subjective.

 

[mthompson]

FYI, just because they at commercial weight doesn't mean that they are at commercial Alpha Acid content. Recipe formulation will still be somewhat subjective.

These are a relic stand of hops I found on a really old rock fence row. I trellised some bines in place this year, and took three home and grew them in large pots. I plan on sending in several samples to BrewLaboratory to get tested so that I have at least a set of average percentages for this year.

Then I will see what I want to do from there (so far they are smelling similar to some Goldings my friend grew this year)....but I am still assuming they are likely Cluster. I haven't had time to check old ag records for our area, but I know they grew hops around here a long time ago (almost every city in WI had breweries in the late 1800's).

 

[GVH_Dan]

Alpha not only depends on variety but also on nutrients, time picked and a host of other things.

If you search for a posting about hop tea by Andrea, there is a method for estimating the alpha acid percentage. It was posted a year or two ago.