Wednesday, 20 October 2010

Hop additions - lots more detail

I warned you. I've loads more of this stuff. about hopping. Just tell me when you've had enough. It won't stop me continuing, but it'll be nice to know.

Let's start with a relatively modern source:

"Addition of Hops to Copper. 
The right time at which to introduce the hops, and the method of so doing, depend to a great extent upon the construction of the copper and the class of beer brewed. Some brewers subject the total quantity of hops to the entire period of boiling. Others reserve about a quarter of the amount to be added to the copper about 10 minutes before the boiling is completed. The latter idea is, in our opinion, the better, as it appears to impart to the wort some of the delicate flavour of the hops which prolonged boiling destroys. In the case of an open copper, the hops may be added with little trouble. With a pressure copper it is almost impossible to add them at this later stage, as it would entail letting down the pressure and opening the dome. As an alternative, we advise reservation of 1/8 of the total quantity to be sprinkled on the plates of the false bottom of the hop-back. This procedure will be found to give the desired effect. The method is especially suitable for pale ales when a delicate hop aroma and flavour is so necessary. There is no need to follow this process in the case of mild ales, or black beers, when a predominant hop flavour is not an outstanding feature."
"Brewing a Book of Reference", 1947, pages 114-115.

Just two additions are recommended: at the start of the boil and 10 minutes before the end. That's the latest hopping mentioned so far. Until the alternative method suggested, that is. That one's after the end of the boil. Though notice that it's only recommended for Pale Ales. Sounds rather like modern IPA brewing techniques.

Moving back in time a couple of decades,here's another view:

Make up the copper within four hours from first setting taps. It is imperative to fix the worts constituents by heat as soon as practicable in order to prevent undesirable changes in the underback or copper before boiling.

Heating destroys the action of diastase,and coagulates the albuminous (protein) matters. The main objects of boiling are to assimilate the flavouring essences of the hops, to secure their preservative properties, and to determine the stability of the worts. To accomplish these objects thoroughly a very strong heat is necessary. The "cooking" of worts can only be accomplished at a temperature of not less than 214° Fahr. The copper must be constantly attended during boiling, and armed with an oar the brewer must learn to keep the worts in the copper without calling for dampers and the opening of the furnace door. Boil vigorously and continuously for two hours — two hours and a half if the produce is to be a light gravity beer, remembering that the violence of the boiling is more important than the time taken, and that lengthy boiling interferes with delicacy. The first half-hour is always a trying time : the worts will kick and bump, and from time to time the hops will cause a "scummy" resinous froth to accumulate With alarming rapidity. Both the kicking worts and the froth will cause the copper to boil over if neglected for a moment, and many gallons of valuable worts may he lost in a few seconds. The subsequent boiling time is less troublesome : the hops with their soluble extract are by this incorporated in the worts and a regular rolling boil ensues ; but even this is treacherous and must be watched. Throw in the remainder of the hops, choice hops for flavour, half an hour before turning out

If worts are boiled in two successive coppers, or lengths, a proportion of the hops should be saved for the second copper, and the spent hops of the first copper returned."
"Practical Brewing and the Management of British Beers", W.H. Nithsdale and A.J. Manton, 1924, pages 36-37.

That's quite a long boil being recommended: two to two and a half hours. Whitbread rarely boiled for longer than 90 minutes in the 1920's. Barclay Perkins boiled a little longer, but boils of more than 2 hours were usually only for higher-gravity beers. The exact opposite of what's stated in the quote.

The text is a bit vague about hop additions. It's two additions again. I assume the first is at the start of the boil (though it isn't explicitly stated. The last addition is, again, 30 minutes before the end of the boil.

The last paragraph - if I understand it correctly - recommends re-using the hops from the first copper in the second. Exactly what W.E. Wright said you shouldn't do. Not very consistent, are they, these old sources?

There's still lot's more to come in this series. I'm just having too much fun to stop.


First Stater said...

Hoppy birthday to you..

Graham Wheeler said...

Wright does not say that you should not return the first hops to the second copper; in fact, in the second paragraph he positively recommends it. What he is against, in the first paragraph, is putting the whole batch of bittering hops in the first copper charge rather than splitting them between the two copper charges.

With late hops added for aroma, the short boiling period does not extract much of the bitterness. So it makes sense to do the aroma hopping in the first copper charge, and then boil the same hops for the full boiling period in the second copper charge to extract the bitterness that would otherwise be lost. Nothing to do with cheapskate brewers at all.

Thomas Barnes said...

Those extracts you've posted show that practical brewers pretty much understood the science of mashing and wort boiling by the 1920s.

Nithsdale and Manton are spot on about wort boil overs, especially in the first part of the boil when most of the hot break begins to coagulate. Their suggested remedies - reduce heat and stir like mad - and are still standard techniques for homebrewers hoping to avoid the sticky mess that is a boilover.