Frequently Asked Questions
Whether you are curious with coffee fermentation, new to inoculating with selected microorganisms or looking to optimise your current practices, our Frequently Asked Questions (FAQ) is packed with practical insights, from instructions, application tips or storage guidelines.
Be ready to elevate your coffee quality.
BACK TO BASICS
What is yeast? What is bacteria?
Yeast is a single-celled type of fungus found in multiple ecosystems. They play a significant role
during coffee fermentation by using nutrients/substrates and converting them into metabolites of
interest.
Bacteria are single-celled organisms that can be found almost everywhere. They take advantage
of the nutritious coffee mucilage especially the organic acids present for aroma modulation.
What is fermentation?
Fermentation is a biological process carried out by microorganisms and mainly yeasts and
bacteria. During coffee fermentation, LALCAFÉ™ yeasts help by degrading the mucilage on the
beans due to their specific enzymatic activities and secondly to reveal the sensory potential of the
beans, due to their specific metabolisms.
Fermentation has a big impact on the final coffee quality, because it contributes directly to the
sensory profile of the coffee. Inoculating with selected yeast controls fermentation, resulting in a
better quality product.
What makes the yeasts different?
- Each yeast is unique and has its own metabolism and enzyme activities that impact on the
coffee substrate resulting in the release or conversion of sensory compounds, which will impact
the demucilagination and the sensory quality. - LALCAFÉ™ yeasts have been characterised and selected for their capabilities to maintain and
improve coffee fermentation and quality during the coffee processing. Many studies carried out
by several research and technical centers recognized by the coffee sector, such as CIRAD, have
confirmed the positive impact of selected yeasts on coffee quality.
APPLICATIONS AND BENEFITS
With which post-harvest processing technique can we use LALCAFÉ™ selected yeasts and bacteria?
LALCAFÉ™ yeasts and bacteria can be used with all post-harvest processing techniques except
when mechanical demucilagination is used.
- Natural dry process (whole fruit). We recommend spraying evenly as the tank if filled or as you
heap on patio. - Depulped process (dry, honey or wet).
How does the selected LALCAFÉ™ yeast work?
The yeast will out compete the indigenous microbes for food on the cherries and thereby providing bio-protection of the coffee.
Why use LALCAFÉ™ yeasts in coffee fermentation?
They will help to:
- Better control the fermentation
- Accelerate coffee demucilagination
- Depending on the LALCAFÉ™ yeasts used and the duration of the fermentation, they will more
or less impact the aroma expression of your coffee. This has been observed in wine, beer and other
fermented beverages - To bio-protect your coffee through out-competing the other microbes present during the
fermentation process. This means we have more of the good microbes controlling the fermentation - To increase the green and roasted coffee shelf life
- Better quality consistency
Why control fermentation with LALCAFÉ™ yeasts?
During the fermentation (minimum 36 hours for impact on flavour), the LALCAFÉ™ yeasts help
to protect the coffee from the growth of undesirable indigenous microflora that can produce
spoilage characteristics, defects or simply unwanted flavours.
What is the impact of inoculating with LALCAFÉ™ yeasts on shelf life/longevity?
Selected LALCAFÉ™ yeasts have a positive impact on the quality of the coffee over time. The
coffee stays fresh for longer and has been shown to improve in quality compared to controls that
drop in quality over the same period.
When is the best time to evaluate coffee inoculated with LALCAFÉ™ yeast?
We recommend that after drying coffee be given at least a month to rest before cupping. Our
experience is that 3 months after processing the coffee, we can evaluate the coffee with accuracy.
YEAST REHYDRATION BEST PRACTICES
How do I use LALCAFÉ™ yeasts?
Yeasts are produced in dry form (active dry yeast) to make their transportation and storage easier.
They have to be rehydrated before use.
- They must be rehydrated in 10 times the volume of water (10 liters for 1kg).
- The rehydration water must be clean (no smell, no chemicals inside), and between 25 ºC and 35 °C.
- Stir gently the yeast into the water to avoid lumps.
- Leave for 20 minutes.
- Inoculate coffee within 30 minutes of rehydration
NOTE: Bring the temperature of the rehydrated yeast to within 5 °C of the coffee mass before inoculation.
What is the dosage?
The optimal dosage is 1 g per kg of coffee. If the water quality is doubtful, an adjustment of the
dosage is required. For example, dirty water (brown color, smell of fermentation, alcohol…), you will
need to increase the dosage to 1.5 g per kg of coffee or double the dosage.
What happens in case of yeast overdosing?
Overdosing will have no impact on final coffee quality.
It will not reduce fermentation time. On the other hand, using too low of a yeast dosage will show
no difference compared to your normal process or your coffee quality.
What if lumps are present?
Lumps are formed because yeast was added too quickly, or it was too cold. To solve this problem,
you should stir again (gently) after 10 minutes of rehydration then let it stand for another 10
minutes to complete the rehydration.
What if I do not see foam?
There is no relationship between foam (which could appear during rehydration) and the
fermentation activities of the yeast. This is just a physical phenomenon of CO released which may
be trapped by the yeast during the drying process. So, foam does not impact the activity of the
rehydrated yeast and they can be inoculated and used for coffee fermentation.
COFFEE INOCULATION
How and when should the coffee be inoculated?
Inoculation (adding the yeast for the coffee fermentation) is done just after pulping or after sorting
the ripe from unripe whole fruit. After the rehydration of the yeast is done (see previous questions),
the inoculation must be carried out.
The inoculation must be stepwise: make sure to add or spray in parts the LALCAFÉ™ yeast
suspension onto coffee, in order to ensure best mixing of the LALCAFÉ™ yeast throughout the
coffee.
Cover coffee on patio with tarpaulin during fermentation.
How long is the fermentation for maximum yeast impact?
We recommend fermentation duration of 36h to 96h to obtain a perceivable aromatic expression of
LALCAFÉ™ yeasts. For dry process duration of 36 to 96h. For Pulped wet process duration 36h to
48h.
Even though demucilagination is complete, continued contact may benefit flavour development,
LALCAFÉ™ yeasts need more time to reveal the coffee aromas.
What is the preferred level of coffee ripeness that can be inoculated with LALCAFÉ™ yeasts with good results?
- Best practice is to use fully ripe cherries.
- We have observed positive results with LALCAFÉ™ yeasts on coffee that has at least 60% ripeness and above.
Can we inoculate different LALCAFÉ™ yeasts in one fermentation?
Different yeasts can be inoculated together, however a lot of research is required for us to be able to
specify the rations to inoculate.
Can we re-use the LALCAFÉ™ yeasts from previous inoculations?
It’s, possible, however
- The mortality of yeast as food depletes during fermentation make the remaining cells unreliable to effectively take over a heavily charged environment.
- During the yeast life cycle, we have yeast autolysis at the end when they die, so if we re-inoculate, we are not sure if there are enough viable yeast cells at that point.
WATER USAGE
When using wet processing, how much water do I have to add to the tank and at which moment in the process?
Add just enough to cover the coffee. Approximately 1 cm above the coffee.
Does the water need to be clear?
Yes, the water used to immerse the coffee must be as clear as possible. If you use recycled water, do
not use water that has been recycled more than twice.
May I re-use water from previous fermentation?
If you are recycling water, never recycle water more than two times.
STORAGE AND SHELF-LIFE OF LALCAFÉ™ SELECTED YEAST
How to store the LALCAFÉ™ yeasts?
- You must keep yeast in a cold and dry place (the best condition is at +4 °C).
- Do not store the yeast in the freezer or below 4 ºC.
- Avoid storage in hot place (up to 30 °C) for more than 6 months.
- Once the bag is opened, use as rapidly as possible (during the following 15 days and it is best to
close it and keep it at +4 °C away from humidity).
What is the shelf-life of LALCAFÉ™ yeasts?
When stored at +4°C, shelf-life is:
- 2 years for LALCAFÉ CIMA™
- 3 years for LALCAFÉ INTENSO™
- 4 years for LALCAFÉ ORO™, LALCAFÉ BRIOSA™, LALCAFÉ BSC™, LALCAFÉ LDP™ and LALCAFÉ INICIO™.
Published Mar 28, 2025 | Updated Dec 22, 2025