Measuring The Aa (bitterness)

[Back Yard Brewer]

Of interest to me is how one would go about measuring the AA if I were to grow my own hops? There must be some sought of measuring equipment that is needed. The answer may be staring me in the face so if it is tell me :unsure:

BYB

 

[Steve]

Of interest to me is how one would go about measuring the AA if I were to grow my own hops? There must be some sought of measuring equipment that is needed. The answer may be staring me in the face so if it is tell me :unsure:

BYB

Never heard or seen of such a device BYB.

 

[DarkFaerytale]

from what i can gather you need to brew beer with your hops and then take it to a special lab for testing, no idea what sort of equiptment they use but i think it would be out of reach to the home brewer/grower

-Phill

 

[Back Yard Brewer]

from what i can gather you need to brew beer with your hops and then take it to a special lab for testing, no idea what sort of equiptment they use but i think it would be out of reach to the home brewer/grower

-Phill

Puts an interesting slant on ones brewing if using your own home grown hops. But I suppose thats what brewing is all about.

BYB

 

[DJR]

There is a simple rough-n-ready titration method where you powderise the hops in a blender, get an equivalent amount of hops with a known AA value, use the same amount of hops in a tea infusion and then add an amount of sugar to each. Based on how much sugar you add to neutralise the bitterness and make them taste the same, you can work out the AA roughly

Eg. add 5g of 5% AA hops to the first cup
5g of ??% AA hops to the first cup

Then it takes 10g of sugar (say) to make the first cup taste palatable
THen 20g of sugar to make the 2nd cup palatable

So you would have roughly 20/10 * 5% AA in the 2nd cup, or ~10% AA hops

Otherwise, yes, a lab analysis will tell you AA percentages.

 

[Whistlingjack]

There are two technical ways to measure AA in hops, both of them require expensive equipment and chemicals. You could contract a lab with this equipment (is there one in Oz?), also expensive. In other words, the measurement is out of reach to us.

On the other hand there is the so-called "hand evaulation" method. This won't tell you what the AA percentage is, but you will get an idea of whether you have bittering, flavour or aroma hops varieties.

Simply dissect the cone with your fingers and observe the quantity of the yellow lupulin glands. If there are many glands inside, the AA will be higher. You will see that in higher AA hops they can be packed and lower AA you may only see a few at each of the bracts.

Then take a few cones between the tips of your fingers hold them close to your nose, rub them together and sniff. You can get an idea of the volatility of the hop oils which will tell you if these are suitable flavour or aroma hops. Obviously more volatile oils are responsible for the aroma.

This takes experience and every crop year will be slightly different. It is better of course to do these tests after you have dried the cones.

Hope this helps.

WJ

 

[Kai]

Grab a handful of pellets, stick them in your mouth and start counting down from ten.

The number you reach when you spit them out in disgust is the approximate alpha acid value.

 

[tangent]

lol Kai

thats where you could just bitter with a known a/a commercial hop and use all your fresh stuff for last minute additions where it's not going to effect the final IBUs much.
Or as Kai has suggested, use your tongue. That's what you'll try to make happy after fermentation anyway. You just gotta visualise way less sweetness.

 

[blackbock]

[snip]
Hope this helps.

WJ

Good to see your studies are paying off for us already, WJ! B)

 

[Murray]

I wonder if wine-testing labs could analyse for AA content.

 

[Screwtop]

There are two technical ways to measure AA in hops, both of them require expensive equipment and chemicals. You could contract a lab with this equipment (is there one in Oz?), also expensive. In other words, the measurement is out of reach to us.

On the other hand there is the so-called "hand evaulation" method. This won't tell you what the AA percentage is, but you will get an idea of whether you have bittering, flavour or aroma hops varieties.

Simply dissect the cone with your fingers and observe the quantity of the yellow lupulin glands. If there are many glands inside, the AA will be higher. You will see that in higher AA hops they can be packed and lower AA you may only see a few at each of the bracts.

Then take a few cones between the tips of your fingers hold them close to your nose, rub them together and sniff. You can get an idea of the volatility of the hop oils which will tell you if these are suitable flavour or aroma hops. Obviously more volatile oils are responsible for the aroma.

This takes experience and every crop year will be slightly different. It is better of course to do these tests after you have dried the cones.

Hope this helps.

WJ

WJ, lots or us here are growing a hop variety called Wurtemberger (same as the state in the south), the rhizomes were sourced from Tasmania and it is supposed to be a very old German Noble Hop. I haven't been able to find any reference or info on this variety in brewing related text or recipes. Have you heard of it in Germany?

Screwy

 

[Doc]

Grab a handful of pellets, stick them in your mouth and start counting down from ten.

The number you reach when you spit them out in disgust is the approximate alpha acid value.

If only I had a home pelletizing machine, so I could use this method
Isn't this also know as the Jayse method ? :beerbang:

Doc

 

[Kai]

blast, i've been sprung.

um, i mean, substitute whole hops for pellets where applicable

 

[Randall the Enamel Animal]

For the Perth crew, Swan will happily do any sort of analysis for you. At a price...

But if you're interested, the package deal is pretty good. OE, AE, ABV, pH, Colour and BU for a hundred bucks.

 

[Lukes]

I used a fair amount of my own home grown hops this year with results I was quite happy with.
I did not use them for bitterness, just in the whirlpool @ flame out, into the no chill cube or dry hop.
Must get/make a hopback for next year . <_<

BYB: Did not answer your question regarding bitterness levels but I hope it helps.

- Luke

 

[Back Yard Brewer]

I used a fair amount of my own home grown hops this year with results I was quite happy with.
I did not use them for bitterness, just in the whirlpool @ flame out, into the no chill cube or dry hop.
Must get/make a hopback for next year . <_<

BYB: Did not answer your question regarding bitterness levels but I hope it helps.

- Luke

Actually that was one idea I did not think about. Using the hops with unknown AA for aroma and buy ones with a known AA bitterness bittering. I assume the level of aroma would not vary as much as the bitterness would either, if I had some old pellets or the like kicking around.

Cheers BYB

 

[Trough Lolly]

Of interest to me is how one would go about measuring the AA if I were to grow my own hops? There must be some sought of measuring equipment that is needed. The answer may be staring me in the face so if it is tell me :unsure:

BYB

Measuring alpha acids in hops is achieved by sample titration using an approved protocol. The content is measured and expressed as a lead conductance value and it's based on percent dry matter in weight - hence the measurement %w/w....

...or you brew it and say "feck that's bitter!" or not! :lol:

I use the 2nd method with my home grown, PoR / Goldings / Chinook.

Cheers,
TL