Scottish Craft Brewers Yeast
Trial
Les Howarth
On 18th January the members of Scottish
Craft Brewers (and a good number of new faces) gathered at the Calton Centre
in Edinburgh to, amongst other things, taste the results of their yeast
trial. Five volunteers had been given the ingredients to brew a standard
recipe. As far as possible, the aim was that the only thing that would be
changed would be the variety of yeast.
The recipe, instructions and ingredients
were supplied by Ian McAnally and involved mashing 4.4 kg of pale malt at
65°C for 70 minutes, sparging, boiling with 77g/AA of East Kent Goldings and
135g/AA of Fuggles copper hops for 60 minutes (adding Irish moss 45 minutes
into boil) and then adding 54g/AA of East Kent Goldings and 88g/AA of
Styrian Goldings aroma hops for 10 minutes of a gentle simmer. Ian
represents the quantities of his bittering hops as weight x alpha acid
content. To obtain weights in g the g/AA figures above have to be divided by
the alpha acid %. The boil was then stopped and 38g each of East Kent
Goldings and Styrian Goldings “End of boil 1 hops”, leaving for 20 minutes,
bringing the temperature of the wort down to 70°C and adding another 38 g
each of East Kent Goldings and Styrian Goldings “End of boil 2 hops” and
leaving for 30 minutes before cooling to fermentation temperature, straining
out the hops and pitching the yeast. The rest of the process was to be "as
usual" with the beers supplied to the January SCB meeting in Cornelius kegs
for tasting and assessment. The target final brew length was 23 litres
(although Ian McAnally brewed 60 litres).
Ian’s yeast was supplied by a local brewery which I shall call “Skudlers”.
Inevitably not all of the brewing went quite
to plan and some of the brews didn't exactly follow the above instructions.
I was interrupted by a phone call so my EOB1 hops got 15 minutes longer (and
EOB2 got 15 minutes less), Tom mashed for 90 minutes instead of 70, Neil had
a problem with a detached water pipe and Ian McManus had all sorts of
problems*. A summary of who brewed what and when is given in the table
below, along with OG and SG at racking (FG).
All of the brews were of a high standard and
the Inveralmond brew would have been judged as "Good" and the others as
"Very Good" under the scoring system.
The Inveralmond brew scored lowest overall
but this was largely due to its cloudiness and consequent low appearance due
to Ian's brewing problems and is not truly representative of the potential
of the Inveralmond yeast. Interestingly perhaps, in spite of Ian's problems,
this brew did not score worst for aroma.
The Skudlers brew scored best overall which
might have something to do with it being one of Ian MaAnally's standard
brews-so he'd had some experience of this recipe, in particular the use of
the large amount of hops that caught some of us by surprise, myself
included. The other 3 brews were broadly similar and on a side by side
tasting I found the White Labs and Safale brews to be indistinguishable but
not everyone agreed with this assessment so maybe my taste buds had become
tired by that stage.
The other three brews scored broadly the
same but it may be of interest to look at which yeast came second (after
Skudlers) for each ranking. The Safale gets the "silver medal" for
appearance which probably fits with its extremely flocculant nature. The
Wyeast comes second on flavour, body and drinkability while the White Labs
yeast does it on aroma.
I am sure that others present might disagree
with my conclusions (see below) but I'd say that the yeast had noticeable
but relatively subtle effects on the beers. It was also noticeable to me how
well the only dried yeast (Safale) had done and its scoring was very close
to the most readily available liquid yeast in the UK (Wyeast).
The average scores in the table above give
no indication of the spread of scores but, without going into the
statistics, the analysis of the data indicates that the Skudlers was better
than average for the group, the Inveralmond was worse than average and the
other three were pretty much the same. However, beer appreciation is very
much a matter of opinion and to give some idea of the range of opinion of
the beers amongst tasters here is an edited (there was some illegibility due
to bad handwriting and smudging due to beer spillage) list of notes made on
the tasting sheets ranging from the least to most favourable:
Inveralmond: Infection?; Too sweet; Yeasty;
nice and malty; Much more drinkable than cloudiness suggests.
White Labs: Astringent/metallic finish;
Harsh hops; Dry finish; Woody flavour; Would have 2nd pint.
Safale S-04: Poor finish; Poor aroma;
Something not right; Slightly harsh; Well rounded; Fruity.
Wyeast: Solvent aroma which dominates
flavour; Slightly harsh; Doughy; Toffee flavour; Peppery.
Skudlers: Balance is poor-hops all the way
through; Simple, spicey; So drinkable-p***ed again.
There is clearly no accounting for taste!
This gives some idea of the range of opinion with both positive and negative
comments for each beer. I liked them all. I'm also wondering whether the
comments on the beer I brewed could relate to tannins in the beer caused by
over sparging, rather than anything to do with the yeast, so hopefully this
exercise will also improve my own brewing practice because of this feedback.
This exercise in yeast comparison clearly
had its limitations, so the results should not be taken too seriously. The
bottom line is that we enjoyed ourselves and it certainly provided food for
thought and discussion. Now the SCB has to decide what it is going to do for
its next research project...
Thanks are due to Davie and Eileen Martin of
Edina Homebrew for laying on an excellent spread of food for us again.
* - The story of Ian
McManus’ brew in his own words: “brewed the goods on 17/12/03 at 10:13. I made a
mistake with the mash temperature and had it far too cool. I will bore you
with the details. Patience is a virtue I must cultivate!
Ran in 9 litres liquor @
92C. Mash tun seemed stable at 80.8C, so stirred in Grain.10:19, temp on top
centre 69.2 (only a little higher than I was seeking) and immersed centre
74C. Stirred again 10:21 temp immersed in corner 73.6C Add 1pt tap water
Temp 71.4. Add 2 pts water temp 70. Add 2 more pts tap water and gave bloody
good stir. Temp 73.3!!!! Added 4 pints cold water, making 9 pints in all.
Temp in corner now 49C. Guess the language in the kitchen. Strained off 1
gallon, raised to 80C and stirred in. 10:44, temp 56C.Heated more wort to 80
10:53 temp 61.6, That will have to do.12:15, final temp 55C.
OG 1043-surprisingly
enough, just on target. Boiled 60 mins etc, etc, pitched Inveralmond yeast.
21/12/03 Racked beer into secondary fermenter at SG 1007 still fermenting
slowly.2 weeks later, into cornelius. disappointingly cloudy FG about 1005.
Hope that tells the story.
