Thursday 6 May 2010

Faulkner's example of a party gyle

Hah. Fooled you. I haven't quite finished with parti-gyling yet.




Today's text will be perfect for any of you who fancy adopting party-gyling. It tells you how to calculate the blends of wort.
"I claim for this work that it is entirely practical, and I therefore give an actual example of a brewing calculated out from first to last; and, in order to render it of the greater service, I purposely take a party gyle, and will say that it is a brewing in which sugar forms a considerable portion of entire extract. We are brewing as follows : Equal lengths of a 22, 20, and 18 lbs. beer, 110 barrels of each, the sugar proportion to be one-fifth, the saccharine in use yielding 86 lbs. per cwt., the malt being reckoned at 87.0 per qr., the wort to be boiled off in two lengths in four separate coppers of varying size. The figures below will, I think, explain themselves, at any rate, with the aid of the few side remarks appended:—

EXAMPLE OF BREWING ESTIMATE, COPPER, AND SUB-DIVISION OF WORT CALCULATIONS.

                       lbs. extract.
110 barrels, at 22.0 = 2420
110 barrels, at 20.0 = 2200
110 barrels, at 18.0 = 1980       1320/36 sugar extract = 37 cwts.


Saccharine proportion   1/5)6600(
                                          1320

Malt extract, at 87 per qr.)5280(60 qrs. 4 bush.
                            522
                           ---- 
                             60

That is, we mash 60 qrs. 4 bush, malt, and dissolve 37 cwts. of sugar to produce quantity required.

The next step is to ascertain copper lengths, in order to obtain 880 nett barrels in collecting vessels.


             Barrels in collecting squares 330

Losses—
Evaporation by boiling off 4 distinct lengths—
                        12 + 12 + 10 + 12 = 46

Hop retention and bulk contraction—
                                  14 + 24 = 38
                                          ----
                                           414 barrels.

This length we distribute as follows :—

No. I. Copper, 125 First wort.
   II. „       125 }
  III. ,,       72 }-Blend as second wort.
   IV. „        92 }
              ----
               414

On the coppers being charged, gravities were found as under, and it is as well to remark that the strong runnings had been more or less divided over entire length:—

First wort,  125 barrels at 32.0 gravity.
Second wort, 125   ,,    at 15.3}
       „     „        72   „     at  8.5}- Or, 289 at ll.l.
       „     „        92   „     at  7.2}

By referring to losses, we see that the first wort evaporates 12 barrels, and diminishes in bulk 14 by hop retention, contraction in bulk, and cooler evaporation. The second blended lengths lose 84 barrels by boiling, and 24 by hop retention, &c, so the nett gathering quantities would be 99 first wort, 281 second wort, making up the 880 barrels required ; while at the same time the gravities would increase as under. First wort, 2.5 per barrel; second wort, 1.7 per barrel. At making up of coppers our calculation stands thus—

Nett result-
      First wort ...   99 barrels at 34.5 = 3415
      Second wort . . 231   ,,    at 12.8 = 2956
                                            ----
                                            6371

that is, as against 6,600 lbs. required ; so that in order to make gravity good, we either add 6 cwt. of sugar to make up deficiency, or as the mean gravity of beers is 20.0, turn out 11 barrels less length, cutting each of the beers 3.75 barrels short in gathering vessels. Before describing the actual subdivision of these worts let me say that if we are merely dividing different lengths of separate worts for a single beer into gathering vessels of various dimensions, there is no difficulty in the matter, since all is accomplished by a simple proportion sum. For instance, taking the brewing in question, as all one beer distributed over vessels, such as the following series : 50, 45, 82, 95, and 58, the proportional division for first wort would be as follows :—

         Total   First   First
        length  Vessel  length
          330 :   50  ::  99    = 15 barrels 

that is, 15 barrels of the first wort would be placed in the fifty-barrel collecting vessel, the proportion for the other vessels being ascertained in the same way. Now, in the case of a "party gyle" a combination of beers of unequal gravities, the varying "strength" is arrived at, of course, by the unequal intermixture of the several worts, and the problem to be solved is what this unequal mixture must be, In the case above we know that we have sufficient wort and extract to give required gravity and length of each beer calculated for. How, then, are we to subdivide 99 barrels at 34.5, and 281 at 12.8 to give in collecting vessels 110 at 22.0, and similar quantities at 20 and 18 ?

The simplest plan is to deal with each beer separately, seeing what excess of extract we shall have if taking all first wort to such beer, and then ascertaining how any excess can be displaced by substituting second wort for first. Thus in the example above it is apparent that by substituting second wort for first, for every barrel of second wort used we displace 21.6 lbs., the difference between 12.8 and 34.5.

We require 110 barrels at 22.0 = 2,420 lbs. Now 110 barrels x 34.5 = 3,795, showing an excess of 1,375 lbs. over required quantity; and if this be divided by difference between gravity of first and second wort, which, as seen above, is 21.6, we find that it will require the substitution of 63.6 barrels of second wort for corresponding first wort, in order to displace the excess lbs. in question. In other words, our beer of 22 lbs. gravity would be made up of 46.4 barrels at 34.5, and 63.6 barrels at 12.8, equalling 110 barrels at 22.0.

The other beers are calculated for in the same manner, and it will be seen that the results come out with perfect accuracy. The rule for division of worts in party gyles may be thus expressed. Multiply each length by gravity of first wort; deduct from result the lbs. extract required, and divide excess by difference between gravity of first and second worts ; the quotient will be the barrels of second wort required, which, subtracted from total, gives barrels of first wort.

It will be perfectly evident that the two calculations I have last given suffice for many purposes in the brewery, such as the proportional distribution of certain bulks into vessels of dissimilar size, the blending of different lengths of a single beer existing at varying final attenuation into separate racking tanks, so that a mean gravity is attained, and also constitute a means of readily calculating the proportional intermixture of two or more beers at dissimilar original gravity, to produce a beer of any mean strength required."
"The theory and practice of modern brewing" by Frank Faulkner, 1888, pages 74 - 77
http://books.google.com/books?pg=PA71&dq=Parti-gyle&id=3DNFAAAAYAAJ#v=onepage&q&f=false


Something has surprised me since I started tis little examination of party-gyling. How little there is about it in the technical literature. Really bugger all. Quite a shock given how prevalent the technique was.

5 comments:

Martyn Cornell said...

Can we have that "Bonks's"* Imperial Mild label as one of the T-shirt choices in the Zazzle panel, ta. I fancy wearing that on the beaches of Lesvos this August.


*For Americans - Wolverhampton/Black Country pronunciation of Banks's

StuartP said...

I just can't wait for 'Party!' to come out on sale. Just imagine what a signed copy would be worth...

StuartP said...

Martin, is that a fashionable new spelling of Lesbos?
Do people now speak of Lesvians?

Martyn Cornell said...

StuartP - the letter 'b' is pronounced 'v' in modern Greek, so the proper pronunciation/transliteration in English of the island that in Greek is Λέσβος is Lesvos. There IS no single letter pronounced 'b', as such, in modern Greek; where necessary they use a combination of 'm' and 'p', so the modern word for 'beer' is spelt, in the Greek alphabet, μπίρα, 'mpeera'.

StuartP said...

Well, vugger me.
Lesvians it is, then.