Best Practices - Bottle Conditioning

How do I bottle condition beer to get the best results?

What is bottle conditioning?

Bottle conditioning is the re-fermentation of beer (or wine, or cider) inside the bottle with added sugar where the carbonation made by the yeast is captured inside the bottle, naturally carbonating the beer (or wine, or cider). This is in contrast to force carbonation where carbon dioxide (CO2) is injected into the beer as a compressed gas.

What are the best practices for bottle conditioning?

Here are our major suggestions:

Use a suitable bottle conditioning calculator (example) to calculate the amount of sugar to add.
Re-yeast the beer to ensure healthy yeast for bottle conditioning.
Use a low pitch rate of re-yeasting, approximately 1 million cells per mL. If using dry yeast, this is approximately 5 g per hL (6 g per bbl) or 1 g in a 20L homebrew batch.
Condition the bottles in stable environmental conditions. Temperature depends on the product and yeast strain used.

Re-Yeasting

Consider re-yeasting if you are bottle conditioning (or keg/cash conditioning). This is especially useful in an acidic beer where the primary yeast will not be healthy. In sour beers, another benefit of re-yeasting is the reduction of THP off-flavour (mousy).

There are several different options for re-yeasting bottle conditioned beers. Champagne-style yeast (e.g. Lalvin EC1118) works quite well for many applications including high gravity and acidic beers. Contrary to some wisdom on the internet, Champagne yeasts don't ferment complex malt sugars and should not dry out a beer beyond what your primary yeast fermented. Champagne yeasts only produce ultra-dry results in ciders or wines where there are only simple sugars (glucose and fructose) to ferment.

Other options include dedicated bottle conditioning strains (CBC-1). Many beer strains can also be used for bottle and keg/cask conditioning including our House Ale EL-D1. The benefit of bottle conditioning with brewing strains is that they often flocculate better than wine yeasts, which may help with achieving less yeast in suspension when the beer is opened and poured.

Acid Shock Starters (Yeast Acclimatization)

Even with a stress tolerant Champagne yeast, re-fermentation can still be a very stressful process for the yeast. The best results are obtained from acclimatizing (adapting) the yeast to its refermentation environment. This is true for both high ABV beers as well as acidic beers. In general, yeast struggles in environments with high levels of acidity and alcohol. This makes ferments like high-ABV sour beer or sparkling wines some of the most challenging environments faced by industrial yeasts.

Here is our protocol for yeast acclimatization by making a liquid yeast starter:

The basic principle is to mix 50% of the beer you want to referment with 50% of starter wort, plus the yeast you are using for re-fermentation and make a starter that helps the yeast adapt to this environment.

Plan for 50 mL of liquid starter per 20L of beer (e.g. 250 mL per 1 hL) and ensure you have a flask/stir plate/stir bar combo big enough to accommodate. For example, if you are refermenting 1000L of beer you will need a 2.5L starter in a flask big enough to accommodate (4L).
Collect half of the starter volume (e.g. for our 1000L example, 1.25L) of the beer you want to re-ferment into the flask. Mix in the other half of the starter volume as either sterile, cooled wort or freshly prepared starter wort (DME or LME).
Add dry yeast at a rate of 5 g per hL (1 g per 20L) to the starter flask. For our example of 1000L, this would mean 50g of dry yeast. In our experience, using EC-1118, House Ale, or CBC-1, rehydration of dry yeast in water is not needed for this protocol.
Stir or shake the flask for 48 hours to let the yeast grow and acclimatize to the new environment.
Pitch this starter into your beer when you are mixing in the sugar for bottle conditioning.

Escarpment Yeasts recommended for bottle conditioning

We mention some of the industry standards above, but you can also consider some Escarpment Labs products below:

House Ale EL-D1 (dry) - Suitable for bottle conditioning of beers under 9% ABV and under titratable acidity of 10 g/L. Benefits: dry strain, clean and neutral flavour, killer factor negative, flocculent.

Hornindal and Voss Kveik - Suitable for bottle conditioning beers greater than 9% ABV and can successfully referment acidic beers. Benefits: killer factor negative, flocculent.

Saison yeast - Use only if your beer was primary fermented with the same saison strain (e.g. French Saison with French Saison). Saison yeasts are highly stress tolerant (acid and ABV) and also produce flavour during bottle conditioning.