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Test - wpływ konkretnych szczepów na cechy organoleptyczne cydru
#1
Temat wpływu na smak i zapach jest jeszcze mało opisany a zauważyłem, że niektórych to interesuje. Wrzucam więc artykuł, który znalazłem jakiś czas temu, niestety jest w języku angielskim, ale jest mz. bardzo ciekawy, szczególnie dlatego, że część z tych drożdży jest dostępna na naszym rynku, a inne też bez problemu można zamówić przez sieć jeśli ktoś bardzo by chciał. Test był fachowo przeprowadzony, badane były szczepy szampańskie, cydrowe, piwowarskie i dzikie. Surowiec był oczywiście ten sam we wszystkich próbach, fermentacja w tych samych warunkach. Na koniec odbyła się ślepa degustacja.

Pozwolę sobie zacytować całość, bo strony w sieci nieraz znikają a wydaje mi się, że jest to artykuł na tyle wartościowy, że warto aby był na forum. Jeśli administracja uzna inaczej to oczywiście proszę kasować/skracać. W późniejszym terminie wrzucę tłumaczenie, ale mam ostatnio mało czasu, jeśli ktoś się pokusi i da radę wrzucić to szybciej to proszę się nie krępować ;).

Źródło: http://www.brewery.org/brewery/library/CidYeast091595.html


Cytat:Yeast Selection for the Production of Hard Cider in Canada
Greg Appleyard,
greg.appleyard@usask.ca

I have noted several questions lately on the variety of yeast one might use to produce hard cider. Last year I ran an experiment to test a variety of yeasts and wrote a small report for the benefit of the people who helped me taste-test the products. My findings may be of interest. I have no connections with the yeast manufacturers and the opinions expressed within should not be taken as a the results of a proper scientific study.
Numerous manufacturers sell general purpose "wine", "champagne", "ale" or "lager" yeasts and local beer and wine supply stores generally have a broad selection of these yeasts (liquid and dried). These yeasts are capable of fermenting grain (malt) and fruit (grapes etc) sugars at various temperatures (4?C to 20?C) and with various characteristics (top or bottom fermentation), but, a "cider" yeast does not seem to be widely available. I, of course, feel this is a grave oversight and is a source of frustration for hard-cider home-brewers.

Yeast variety as an important contributor to any beverage's mouth-feel, aroma, and winning taste is not to be under-estimated. Just as a low attenuated lager yeast would be a poor choice in brewing an Imperial Stout, some yeasts may be poor choices in brewing hard cider (hereafter known as cider). Similarly, wine makers would balk at making champagne with a yeast better suited to a heavy red wine.

So what is a Canadian cider home-brewer to do? Well, short of engineering your own yeast strain, one option is to test the commercially available yeasts. Conventional wisdom is that wine and champagne yeasts are more tolerant of the toxic effects of alcohol than beer yeasts and therefore will produce a drier drink with a higher percentage of alcohol (given available sugar of course). With this advice, many mead makers use wine or champagne yeasts to generate potent elixirs or beer yeasts to produce sweet mellow meads. The alcohol content of cider, however, need not be that much greater than a strong beer (5-7%) (not including applejack and apple wine) and so an entire range of beer and wine yeasts need to be examined for their ability to contribute favourably to a tasty cider.

This article, therefore, reports on my continuing quest to home-brew cider in Canada and was built on the foundations of last year's successful experiment on apple varieties and their contribution to the flavour and aroma profile of hard cider. Given the best apple variety blend recipe researched last year, I made 10 gallons of blended juice with which to test 10 yeast strains in 1 gallon batches.

The test batches consisted of 65% Golden Russet, 11% Paula Red, 16% Greenwoods (a wild variety whose location is kept secret!), 2.7% Tremblett's Bitter (an european cider apple), 5.3% Red Delicious. The juice was obtained by pressing each variety separately in a hand cranked wooden apple press and stored frozen for several weeks prior to blending. The blended juice had a S.G. of 1.057 and a pH of 2.8.

From a local beer supply store I obtained packets of dried Doric Ale yeast, Cooper's Ale yeast, Lalvin red wine yeast #1116, Lalvin champagne yeast #1118, Lalvin sherry yeast #1226, Red Star Montrachet wine yeast. Agar slants of a german wheat beer yeast "mike" and a commercial cider yeast "george" were donated by friends (to whom I am very grateful). YeastLabs liquid culture of British Ale yeast was purchased from a mail-order beer supply company. The tenth gallon of cider was simply allowed to ferment by the organisms surviving in the blended juice ;"wild". Following fermentation approximately 1 oz of granulated white sugar was added to raise the S.G. to 1.005 and 0.02% sodium benzoate was added as a stabilizer (this is less than the concentration of benzoate used in soft drinks to keep them from fermenting).

The resulting ciders were subjected to aroma and flavour sensory evaluation by a panel of people (willing members of the general public, who also happen to be good friends of mine, but were completely impartial). Their comments (the polite ones) and preferences were recorded and tested by rigorous statistical analysis.

All ciders were very clear regardless of the yeast variety and from last year's experiment this characteristic seems to be a variable associated with apple variety. The most pleasing colour seemed to be a golden yellow colour (mike, george, wild) and not a pale yellow colour (L1226, RS-Montrachet, L1118, L1226) nor a too dark brown colour (Cooper). The most pleasing aromas were associated with a tangy, fruity or apply smell (wild, george, cooper, L1226) but not a musty, heavy, yeasty, old-mushy-apples smell (British Ale, RS-Montrachet, Doric, Cooper). Interestingly, the wheat beer yeast "Mike" generated a distinct butterscotch smell and while interesting, was not considered by most to be overly desirable even though it fared well in colour and flavour categories.

The most pleasing flavours were associated with crisp, apply, fruity, slightly acidic or sharp tastes (wild, L1118, george, Doric, Cooper, mike). Mild, flat, too bitter or wine-like flavours were not scored highly (British Ale, L1226, L1116, RS_Montrachet). The after-tastes which scored highly were crisp, slightly bitter or complex (wild, L1118, mike) while too acidic, yeasty, or cloying after-tastes were found disagreeable (British Ale, RS-Montrachet, Doric).

Average score, out of 30 possible points resulted from numerical evaluations of pleasing aroma, colour, taste, acidity, after-taste and mouth-feel and voting results for the top three most drinkable ciders are listed below.


Kod:
Score (30)  votes
   wild          23.9       13
   L1118         21.9       11
   mike          21.2        2
   george        21.1       11
   Cooper        20.4        2
   Doric         19.0        0
   RS-Mont       17.8        0
   L1226         15.4        5
   L1116         14.2        1
   YL-Brit       11.8        0


Since the juice was all from the same blend, fermented and stored under the same conditions, these observations may be attributed primarily to the workings of the individual yeasts.

Several lessons can be learned from this experiment. Wild yeasts, generally despised by home-brewers but abundantly available on fresh fruit and in unpreserved juice, can be used successfully to brew delicious cider. I believe I shall be following techniques outlined in previous Newsletters on culturing yeasts to try and preserve this isolate(s). A word of caution, wild yeasts are notorious for variability. One year the cider may be award-winning but could equally be putrid.

No one group of yeast (beer or wine) was more successful at producing a tasty cider than the other. The top scoring three ciders were produced by a wine yeast, a beer yeast and wild yeasts. To generalize though, the beer yeasts tended to produce off-smelling musty ciders more so than the wine yeasts.

Although light in colour and faint of aroma, the cider produced by L1226 received favourable comments by those drinkers who liked a champagne style of cider. The "george" yeast was a proven cider yeast from an american cidery and so is not surprising that it fared well in scoring. It was interesting that the commercially available yeast L1118 performed nearly as well as the specifically cider-adapted yeast "george". The two yeasts produced very different flavours and aromas but were judged to be equally pleasing. The wild yeast(s) produced a complex cider with a crisp flavour and clean after-taste, "a roller-coaster of flavour".

To conclude, home-brewers need not fret about the availability of yeasts with which to make great cider. It just takes a bit of experimentations to find the one that suits your tastebuds best.



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