Copied verbatum, Yeast section, Chapter 11, from "The Home Winemakers
Manual".
WINE YEASTS
The flavor characteristics
of wine depend upon many factors. However,
the yeast used for fermentation contributes little to the flavors of aged wine,
and most flavor contributions from the yeast will be undetectable in wines aged
in oak barrels for normal periods. Many
other winemaking factors such as fruit quality, grape variety, the climate,
fermentation temperature, lees contact, cap manipulation, etc. influence wine
flavors much more than yeast.
Light bodied, fruity wines
are exceptions. These wines are bottled and consumed when they are young, and
the effects of the yeast are still noticeable.
Under these conditions, subtle flavor and aroma variations can be
produced by different strains of yeast.
YEAST CHARACTERISTICS
Large differences in wine
yeasts do exist. However, these
differences relate to properties other than creating wine flavors. Yeast characteristics important to
winemakers include speed of fermentation, color extraction, how much alcohol is
produced, tendencies to stick, the quantity of foam generated, hydrogen sulfide
production, etc.
A few wineries use a
different type of yeast for each wine produced. Many smaller wineries ferment all of their wines with only one or
two types of yeast. The research winery
at the University of California at Davis uses a single yeast type for all
standard fermentations. Smaller
wineries and home winemakers often use Prise de Mousse yeast for all their
fermentations.
Yeast names often mislead
and confuse novice winemakers. For
example, Pasteur Champagne yeast is not very good for sparkling wine
production. California Champagne or
Prise de Mousse are better yeasts for the secondary fermentation of sparkling
wines. Instead of implying use, the
name shows the yeast strain originally came from the Champagne district of
France. To complicate matters further, the same name is sometimes used by
different yeast manufacturers to identify completely different yeast
strains. A few years age, two entirely
different yeast strains of yeast were available commercially, and both were called “Prise de Mousse.” When placing orders for yeast, winemakers
can avoid confusion by providing the name of the yeast, the name of the manufacturer and the yeast
designation number.
YEAST TYPES
Wine yeast can be purchased
in both liquid and dry forms. However,
dry yeast is easier for small wineries and home winemakers to use. Recommended
applications of some popular, dry Lalvin
yeasts are shown in Figure 3, and some important yeast characteristics are
shown in Figure 4.
Figure 3. Recommendations for Lalvin
active dry yeasts.
Yeast White Red Champagne Bottle Stuck
Strain Wine Wine Base Ferment Ferment
M-1107
X X
V-1116
X X X
E.C.-1118
X X X X X
C-1108
X X X X X
Figure 4. Yeast Characteristics of
special interest to winemakers.
Yeast Prise
de Pasteur
Characteristic Montrachet K-1 Mousse Champagne
Fermentation Rate Fast Slow Fast V.
Slow
Completeness Good V. Good Good Good
Alcohol
Toll. 15% 15% 18% 17%
Sugar
Toll. Good Good To 34 B Good
Opt.
Temp. (C) 20 20 15 20
Temp.
Range (C) 15-25 15-30 10-25 15-25
Alcohol
Yield High High Medium N/A
Foaming High Low V. Low Medium
Flocculation Normal Normal V.
Good Normal
Epernay II
This is a popular yeast for
producing light fruity style white and blush wines, and Epernay is also popular
for producing wines made from fruit other than grapes. Sometimes Epernay is used for producing
light, fruity style Chardonnay
wines. However, Chardonnay juice
can be difficult to ferment completely, and stuck fermentation often results
when Epernay yeast is used with Chardonnay.
Chardonnay wines fermented with Epernay yeast should be closely
monitored and tested for residual sugar.
Epernay is used at
fermentation temperatures ranging from 50 to 70 degrees. Under these conditions, it produces slow,
controlled fermentations, and volatile components in the juice are retained
well. Excessive foaming is seldom a
problem when Epernay is used. Epernay does
not ferment well at low temperatures, and it is very sensitive to sudden
changes in fermentation temperature (cold shock). Epernay is often used when winemakers intend to leave some
residual sugar in a wine. Usually,
active Epernay fermentations can often be stopped just by lowering the
temperature of the tank.
Epernay yeast is sensitive
to high alcohol levels.
Consequently, Epernay should not
be used in juices with high Brix values unless some residual sugar is wanted. Epernay yeast can produce very pleasant,
fruity aroma characteristics in young wines, and home winemakers use Epernay
yeast for fermenting fruit wines because of the fruity aromas produced. This yeast is available in five gram
packets, 500 gram packages and in bulk form.
California Champagne (UCD 505)
This yeast is used primarily
for the secondary fermentation of sparkling wines. It produces a simple, clean, yeasty fermentation, and these
characteristics are desirable in most sparklers. After a reasonable aging period, UCD 505 yeast will flocculate
into large clumps, and the large pieces of yeast are much easier to
riddle. UCD 505 yeast is sensitive to
alcohol and sulfur dioxide. To insure
prompt, clean secondary fermentations, the free SO2 level of the cuvJe should not exceed about 25
milligrams per liter, and the alcohol content should be less than 11
percent. Small quantities of yeast
nutrient are often used with this yeast.
UCD 505 is available only in 500 gram packages and in bulk.
Montrachet (UCD 522)
Montrachet was a very
popular yeast for producing well-colored red wines and big white wines for many
years. Montrachet produces strong,
vigorous fermentations, and some type of cooling is often necessary in warm weather.
Unfortunately, Montrachet
yeast often produces excessive quantities of hydrogen sulfide, and it has
fallen into disfavor in recent years. Grapes low in nitrogen should always be
augmented with a yeast nutrient or DAP when Montrachet yeast is used, and
prudent winemakers make it a point to smell all Montrachet fermentations
several times each day. Montrachet
yeast should never be used with grapes containing residual sulfur dust. This yeast is available in five gram
packets, 500 gram packages and in bulk.
Pasteur Champagne (UCD 595)
Contrary to its name,
Pasteur Champagne yeast is not well suited for sparkling wine secondary
fermentations. It can be used for
sparkling wines, but UCD 595 produces very fine lees, and the light, fluffy
lees make riddling difficult. Pasteur
Champagne yeast is tolerant of high alcohol levels and sulfur dioxide, so it is
often used to restart stuck fermentations.
Some wineries use this yeast for both white and red fermentations, and
it can be counted on to produce clean, neutral fermentations. When used under reasonable fermentation
conditions, it seldom leaves residual sugar.
Sometimes Pasteur Champagne yeast produces large quantities of foam in
warm weather. This yeast is available
in five gram packets, 500 gram packages and in bulk.
Prise de Mousse (E.C. 1118)
Since it became available in
dry form several years ago, the popularity of Prise de Mousse (PDM) yeast has
increased rapidly. PDM is an excellent,
general purpose yeast for both red and white wines. It produces low hydrogen sulfide fermentations, and it ferments
vigorously. Since this yeast usually
produces a dry wine, it is one of the more popular yeasts for California
Chardonnay production. This yeast is
tolerant to sulfur dioxide, and it is tolerant to high alcohol levels. Consequently, Prise de Mousse is useful for
restarting stuck fermentations. Prise
de Mousse is also used for the secondary fermentation of sparkling wine. Under normal conditions, Prise de Mousse
produces little foam and seldom causes the winemaker any trouble. Smaller wineries often use this yeast for
all their fermentations. PDM is
available in five gram envelopes, 500 gram packages and in bulk.
Steinberg
Steinberg yeast is used for
producing classical, “cold fermented” Riesling wines, and it is used
extensively for Gewurztraminer production.
When used at low fermentation temperatures, Steinberg produces a
delicate, complex bouquet of fruit odors in young white wines. This yeast is very cold tolerant, and it
often continues fermenting at temperatures below 40 degrees. However, this yeast is very sensitive to
sulfur dioxide, and Steinberg fermentations can be retarded significantly if
more than 50 milligrams per liter of sulfur dioxide are added at the crusher. Sometimes, winemakers can deliberately stop
low temperature Steinberg fermentations just by adding a large dose of sulfur
dioxide to the tank. This yeast is only
available in 500 gram packages and in bulk.
Pasteur Red
Pasteur Red yeast has been
available commercially for some time, but it has only been produced in dry form
for the past several years. In dry
form, Pasteur Red is rapidly becoming the yeast of choice for producing
full-bodied red wines. Pasteur Red
produces clean fermentations, and it has good color extraction characteristics. This yeast seems particularly well suited
for fermenting deeply colored Bordeaux style red wines. Pasteur Red yeast is vigorous, and some
cooling is often needed in warm weather.
Pasteur Red yeast can be purchased in five gram packets, 500 gram
packages and in bulk form.
SUMMARY
The type of yeast used for
fermentation has little influence on the aromas and flavors of aged wines. However, yeast can contribute to the aroma
of young, fruity wines.
Yeast is available in liquid
and dry form, but dry yeast is much easier for small producers to store and
use.
Prise
de Mousse yeast produces little foam and seldom causes fermentation
problems. Some small wineries use Prise
de Mousse for all of their red and white fermentations, and they also use it to
restart stuck fermentations.
