Understanding Yeast: Which Strain to Choose and Why

Yeast doesn't just convert sugar to alcohol — it actively shapes the flavour, aroma, texture, and finish of your wine. Two winemakers starting with identical grapes and identical conditions but using different yeast strains will produce detectably different wines. Understanding yeast strains is one of the fastest ways to level up your winemaking.

What Wine Yeast Actually Does

All commercial wine yeasts are strains of Saccharomyces cerevisiae, the same species used for bread and beer. What distinguishes strains from each other:

• Alcohol tolerance — the maximum ABV the yeast can survive
• Fermentation temperature range — the range within which the yeast ferments cleanly
• Ester and volatile production — the flavour-active compounds the yeast produces
• Nutrient requirements — some strains are nutrient-hungry; others are robust in low-YAN musts
• Malic acid metabolism — some strains (notably 71B) partially metabolise malic acid during fermentation
• Flocculation — how quickly the yeast settles out when fermentation ends

Core Strains Every Winemaker Should Know

EC-1118 (Prise de Mousse / Champagne)

Best for: Sparkling base wine, high-sugar musts, restarting stuck ferments, ciders
Alcohol tolerance: 18%
Temperature: 10–30°C
Character: Completely neutral. Produces very little in the way of flavour compounds — it just ferments vigorously and completely. Fast, reliable, unfussy.
Note: Because it's so vigorous and neutral, EC-1118 can strip delicate aromatics from wines. Only use it for sparkling, stuck fermentation rescue, or high-ABV meads where you don't want yeast character.

71B

Best for: Country wines, meads, fruit wines, rosés
Alcohol tolerance: 14%
Temperature: 15–30°C
Character: High ester production — pronounced fruity, floral aromatics. Metabolises 20–40% of malic acid during fermentation (natural acid softening without MLF). Produces a round, approachable wine with minimal harsh edges.
Note: The most popular choice for elderflower, elderberry, blackberry, and most country wines. Its malic acid reduction is particularly valuable when working with high-acid fruits.

RC212 (Bourgovin)

Best for: Pinot Noir, Gamay, light reds
Alcohol tolerance: 16%
Temperature: 20–30°C
Character: Enhances colour stability and spice character. Moderate ester production. Produces structured, aromatic red wines typical of Burgundy style.
Note: Quite nutrient-hungry — give it a full TOSNA protocol.

D47

Best for: Chardonnay, Viognier, aromatic whites, traditional mead
Alcohol tolerance: 15%
Temperature: 15–20°C — critical
Character: Excellent aromatic expression of terpenes and esters. Produces a round, creamy mouthfeel. Mead made with D47 is often buttery and complex.
Warning: If D47 ferments above 20°C it produces significant amounts of fusel alcohols, which smell and taste harsh. Keep it cool — this is non-negotiable.

QA23

Best for: Sauvignon Blanc, Pinot Grigio, aromatic whites
Alcohol tolerance: 16%
Temperature: 12–25°C
Character: Releases bound terpenes, producing grassy, tropical, passion-fruit aromatics typical of New World Sauvignon Blanc. Fast fermenter.

K1V-1116 (Montpellier)

Best for: Difficult fermentations, stuck ferment restarts, country wine, mead
Alcohol tolerance: 18%
Temperature: 10–35°C — extremely robust
Character: Neutral to very slightly fruity. Extremely resilient across temperature and alcohol extremes.
Note: The emergency strain. Keep it in your cupboard — if any fermentation gets stuck, K1V-1116 will restart it.

R2

Best for: Bordeaux reds, Malbec, Shiraz
Alcohol tolerance: 17%
Temperature: 14–28°C
Character: Full body, colour stability, dark fruit character. Reliable finisher for high-extract red wines.

Manufacturer Comparison

Dried sachets are more practical for home winemakers — longer shelf life, no cold chain required.

How to Rehydrate Yeast Properly

Yeast survival at pitching depends on correct rehydration. Dry yeast cells have fragile membranes — shocking them into cold must causes significant cell death.

1. Heat 50mL of water to 35–40°C (not hotter — you'll kill them; not cooler — they won't rehydrate)
2. Sprinkle the yeast on the surface. Don't stir yet.
3. Wait 10–15 minutes until you see a creamy foam forming
4. Stir gently. The yeast is now active.
5. Gradually temper the yeast by adding a small amount of your must and waiting 10 minutes. Repeat twice. This prevents temperature shock.
6. Pitch into your main must.

For Go-Ferm rehydration nutrient: dissolve 1.25g per gram of yeast in the rehydration water. It improves yeast vitality significantly.

Choosing for Your Wine