Old hops: how do they differ from fresh

[patto1ro]

I have a question about the use of old hops that I hope one of you professionals might be able to answer.

Old brewing logs are a wonderful source of information. They have details of the source and date of all the ingredients. What I've noticed, in the ones from British breweries, is that they often use hops one or two years old.

I know why they did this - the hop harvest was incredibly variable and the price could quadruple from one year to the next. Which is why breweries bought extra in bumper years to see then through the bad ones.

But what is the difference, in terms of bitterness and aroma between fresh hops and those that are a year or two old? I'm talking 19th century here, so they weren't storing their hops in freezers.

To be specific, do you agree with the IBUs that have been calculated from old brewing books in this article:

http://www.brewlab.co.uk/pdf/yeasts%20of%20yesterday.pdf

They look very high to me.

[tariq khan]

Hops

Interesting article by Dr Keith for sure, I have studied with him and remember a lecture about old breweries more specifically the Hammond Brewery. From what I remember the hops were stored for sometimes long periods in cool but not cold conditions and were limited to a few varieties that were grown in Kent.
Alpha acids were quite low and storing them reduced them further, which is probably the reason they boiled for 2-3 hours. Of course hop additions were quite high back then. If fresh hops were available they were acquired but I don't think aroma was that much of an issue.
In regards to the IBU's I think they are correct considering that beers back then were apparently more bitter and harsh tasting (as well as smokey).

Tariq (Dark Star Brewery)

[dick murton]

In terms of alpa acid, the age doesn't seem to make much difference based on my experience, but the aroma changes enormously. I had the dubiousl pleasure of using 6 year old hop pellets once, at about 2% alpha. When these stocks were used up and we started using "normal" hops at 4.8 % +, the change in character was quite amazing. The beer lost some richness in mouthfeel and aroma, to the extent that I suggested (toungue in cheek of course) that we should throw in some cabbages to give the vegetable flavour back. I actually preferred this particular beer before we ran out of the old stale hops. I think the main thing if brewing commercially is to keep the ingredients, including hop type and age very consistent.

Have fun

Cheers

[rudge75]

You may want to read up on and explore lambic brewing with special attention to hop storage and hopping. Given the poor storage conditions and the depletion of Alpha acids, the beta acids would play into effect more, and I believe lambic brewers put more emphasis on the beta fraction because it survives extended storage better.

I'm pretty sure the "wild brews" book touches on this.