I will be starting a new project soon where I will be fermenting quite a bit of Agave nectar, now I know from the last time I took on a project like this that Agave is a notoriously difficult fermenter requiring a lot of help.
Has anyone around here had any sucess, failure, or lessons in general about fermenting agave? Oskaar?
Specifically, I'm looking for:
1) Sugar density - I've learned that 60% in solution or about 60 brix is way too high. What's the ideal?
2) Yeast type - There is very, very little info out there on what the Tequila producers in Mexico use to ferment their product, does anyone know anything about what type of yeast is best for this application?
3) Yeast nutrition - Depending on what yeast is selected in #2 above, what is the best nutrition regime knowing that Agave is generally deficient in nitrogen and metal micronutrients.
4) Other experiences - war stories? Lessons?
Some additional information that may be needed: This will be a completely pure varietal fermentation of diluted (in water) agave nectar imported from Mexico. The "wort" will not be mixed with any type of grain or extract from grain nor will the "wort" or "must" be mixed with anything else besides water, yeast, and yeast nutrient.
Thanks in advance everyone!
Agave Fermentation
Moderator: Post Moderators
Here's my .02:
1. K1-V1116 or 71B-1122 are the two preferred yeasts for primary fermentation by most of the larger Tequillerias based on my conversations with Clayton Cone of Lallemand.
2. Start with your brix at around 30-32 (should be in the neighborhood of about 2 gallons of agave syrup)
3. Prepare the yeast using Go-Ferm to rehydrate. In the case of agave I would recommend that you use a 2 liter starter (either apple juice or a honey/apple juice mixture). I personally have used a 2 liter starter with K1 with great results.
4. Keep the temperature to the high side of 68-72 degrees F
5. Use a staggered nutrient addition with lots of aeration during the first 72 hours of fermentation. Go with 10 grams DAP in the must before pitching your yeast. At the end of the lag phase go with an addition of 5 grams Fermaid K + 2 grams DAP. At the 1/3 sugar break add another 4 grams of Fermaid K, aerate well and airlock.
6. Keep an eye on your pH during the first 24 hours. If it drops below 3.2 use some K bicarbonate to buffer it to 3.6 - 4.0
7. To make your starter rehydrate your K1 as per Lallemand's recommended procedure (Go to more winemaking dot com and look in the more manuals for the publication on Proper Yeast Rehydration) Once you have the yeast rehydrated you can add that to 2 liters of apple juice or a mixture of apple juice and honey. Let it get going (probably about 4-6 hours tops) and then add an equal amount of your Agave must. Once it's going strong, add it into your remaining must and stir the sh!t out of it.
That's generally how I've done any agave that I've made.
Feel free to ask more questions.
PS. Don't heat your must, you'll drive off the oxygen and kill off the beneficial protiens and enzymes that occur naturally in the Agave that will help in the fermentation.
Oskaar
1. K1-V1116 or 71B-1122 are the two preferred yeasts for primary fermentation by most of the larger Tequillerias based on my conversations with Clayton Cone of Lallemand.
2. Start with your brix at around 30-32 (should be in the neighborhood of about 2 gallons of agave syrup)
3. Prepare the yeast using Go-Ferm to rehydrate. In the case of agave I would recommend that you use a 2 liter starter (either apple juice or a honey/apple juice mixture). I personally have used a 2 liter starter with K1 with great results.
4. Keep the temperature to the high side of 68-72 degrees F
5. Use a staggered nutrient addition with lots of aeration during the first 72 hours of fermentation. Go with 10 grams DAP in the must before pitching your yeast. At the end of the lag phase go with an addition of 5 grams Fermaid K + 2 grams DAP. At the 1/3 sugar break add another 4 grams of Fermaid K, aerate well and airlock.
6. Keep an eye on your pH during the first 24 hours. If it drops below 3.2 use some K bicarbonate to buffer it to 3.6 - 4.0
7. To make your starter rehydrate your K1 as per Lallemand's recommended procedure (Go to more winemaking dot com and look in the more manuals for the publication on Proper Yeast Rehydration) Once you have the yeast rehydrated you can add that to 2 liters of apple juice or a mixture of apple juice and honey. Let it get going (probably about 4-6 hours tops) and then add an equal amount of your Agave must. Once it's going strong, add it into your remaining must and stir the sh!t out of it.
That's generally how I've done any agave that I've made.
Feel free to ask more questions.
PS. Don't heat your must, you'll drive off the oxygen and kill off the beneficial protiens and enzymes that occur naturally in the Agave that will help in the fermentation.
Oskaar
Don't go into the Pimped-Out-Refrigerator Jack!
Thanks Oskaar, that's a lot of really great information.
A couple of follow up questions:
1) What batch size are you working with? From what I've read so far two gallons of agave syrup would be about 30 lbs and ~30 brix requires dilution of approximately 1 lb of agave to 1 gallon of water. This would be a 30 gallon fermentation, right?
2) I have also heard that the brix should be lower to prevent "stuck" fermentations. Others have been successful with a brix around 14. I'm assuming that you can increase the brix with appropriate nutrition additions, but going to 30 brix from 14 brix is significant.
3) When you talk about "lots of aeration" are you talking vigorous stirring or are you talking about O2 injection?
4) Your nutrient requirements make a lot of sense and go well with other suggestions I have heard, but what is the batch size you have in mind? They seem a bit light unless you are talking about a ~10 gallon fermentation.
4) I will be getting the yeast brought up from the dry culture by a friend of mine in her microbiology lab. When you pitch, are you pitching 500mL of slurry, 1L of slurry or what? And again, what is the batch size you have in mind?
A couple of follow up questions:
1) What batch size are you working with? From what I've read so far two gallons of agave syrup would be about 30 lbs and ~30 brix requires dilution of approximately 1 lb of agave to 1 gallon of water. This would be a 30 gallon fermentation, right?
2) I have also heard that the brix should be lower to prevent "stuck" fermentations. Others have been successful with a brix around 14. I'm assuming that you can increase the brix with appropriate nutrition additions, but going to 30 brix from 14 brix is significant.
3) When you talk about "lots of aeration" are you talking vigorous stirring or are you talking about O2 injection?
4) Your nutrient requirements make a lot of sense and go well with other suggestions I have heard, but what is the batch size you have in mind? They seem a bit light unless you are talking about a ~10 gallon fermentation.
4) I will be getting the yeast brought up from the dry culture by a friend of mine in her microbiology lab. When you pitch, are you pitching 500mL of slurry, 1L of slurry or what? And again, what is the batch size you have in mind?
Hey dude,
See my comments in blue below each of your questions:
1) What batch size are you working with? From what I've read so far two gallons of agave syrup would be about 30 lbs and ~30 brix requires dilution of approximately 1 lb of agave to 1 gallon of water. This would be a 30 gallon fermentation, right?
Nyt.
I'm talking about 6 gallon batches. Agave is about 11-12 lbs/gallon unless it is far more dense than honey, which I've never seen in my experience. For a 30 brix batch @ 6 gallon size it should take between 15-17 lbs or more of agave syrup in my experience. The amount of syrup necessary depends on the water content of the agave plant, and by extension the syrup (depending on the time of year and time proximity to the most recent rainfall) the agave can vary up or down so rather than using lbs/gallon as a measure it is more accurate to use the hydrometer (I usually take three measurements for my musts using two triple scale hydrometers and a narrow band hydrometer to ensure I'm on the mark) as there is significant variance in agave syrup just as there is in honey.
2) I have also heard that the brix should be lower to prevent "stuck" fermentations. Others have been successful with a brix around 14. I'm assuming that you can increase the brix with appropriate nutrition additions, but going to 30 brix from 14 brix is significant.
High gravity/high sugar musts are only a problem when one mistakenly chooses a yeast that is not designed for high starting sugar musts. High osmotic pressure can adversely affect the onset and health of the fermentation if the yeast is not correctly matched to the must. In my previous post I mentioned K1, 71B and Uvaferm 43. With the higher starting brix stick with Uvaferm 43 or K1, if you go to a lower brix like 24 71B will work well too. At 30 brix you are on target for an ABV of about 17%, if you want to go less that's fine too.
However, if you start out at 14 brix your ABV Potential is about 7.3% which is too low to inhibit other competitive bacteria and yeast that can overtake your fermentation and infect your batch. You should start at a minimum of about 24 brix which puts you at 14% ABV which will inhibit all but the heartiest spoilage bacteria. It is also necessary to encourage a fast fermentation as the naturally occuring yeast and bacteria in the agave syrup will also succumb to rapidly changing osmotic pressure and rising alcohol by volume.
3) When you talk about "lots of aeration" are you talking vigorous stirring or are you talking about O2 injection?
O2 injection is fine but I generally use a combination of O2 injection and stirring with a whip degasser or a lees stirrer. You want the must agitated and more importantly you want the yeast up in suspension as much as possible. This brings up another issue and that is highly clarified must. If your must is highly clarifed (i.e. low to no turbidity) you'll need to add yeast hulls in order to help your yeast stay in suspension. Add as per manufacturer's suggestion per wine musts. Aerate at least twice daily during the first phase of fermentation (up to the 1/3 sugar break) and then just stir so as not to aerate during the second third of fermentation. Use a lees stirrer or a long handled stirring spoon.
4) Your nutrient requirements make a lot of sense and go well with other suggestions I have heard, but what is the batch size you have in mind? They seem a bit light unless you are talking about a ~10 gallon fermentation.
These are modified Staggered Nutrient Addition (SNA) schedules I use when making certain honey musts and when I've made agave must. Using more will leave a salty/metallic flavor in your finished product in my experience. This is my generally used addition schedule for 6 gallon batches and is in accordance with recommendations from Lallemand and Scott Laboratories.
4) I will be getting the yeast brought up from the dry culture by a friend of mine in her microbiology lab. When you pitch, are you pitching 500mL of slurry, 1L of slurry or what? And again, what is the batch size you have in mind?
I'm generally pitching 12 grams of yeast rehydrated in 100 ml of H20 at 111 F. It is very important to follow the Go-Ferm yeast rehydration process exactly or all bets are off. Once the temp is down to 104 F add your yeast, stir and let sit for 15 minutes and stirr again. Then add an equal amount of your agave must, stir and then add that the mixture to the rest of the must. If you're building a 2 liter starter do the same thing with the starter and let it get going good and strong before you pitch. This is for a six gallon batch.
I STRONGLY recommend against using a slurry from a friend unless you've specifically used it in agave musts. Agave is notorious for becoming stuck or undergoing a slow and protracted fermentation which is not desireable. It costs less than $10 for the Go-Ferm, Active Dry Yeast (K1 or UvaFerm 43) Fermaid-K and DAP to do this with proven yeast strains and nutrients. Why risk the investment $$$ with an unknown even if it is coming from a microbiology lab?
My .02,
Oskaar
See my comments in blue below each of your questions:
1) What batch size are you working with? From what I've read so far two gallons of agave syrup would be about 30 lbs and ~30 brix requires dilution of approximately 1 lb of agave to 1 gallon of water. This would be a 30 gallon fermentation, right?
Nyt.
I'm talking about 6 gallon batches. Agave is about 11-12 lbs/gallon unless it is far more dense than honey, which I've never seen in my experience. For a 30 brix batch @ 6 gallon size it should take between 15-17 lbs or more of agave syrup in my experience. The amount of syrup necessary depends on the water content of the agave plant, and by extension the syrup (depending on the time of year and time proximity to the most recent rainfall) the agave can vary up or down so rather than using lbs/gallon as a measure it is more accurate to use the hydrometer (I usually take three measurements for my musts using two triple scale hydrometers and a narrow band hydrometer to ensure I'm on the mark) as there is significant variance in agave syrup just as there is in honey.
2) I have also heard that the brix should be lower to prevent "stuck" fermentations. Others have been successful with a brix around 14. I'm assuming that you can increase the brix with appropriate nutrition additions, but going to 30 brix from 14 brix is significant.
High gravity/high sugar musts are only a problem when one mistakenly chooses a yeast that is not designed for high starting sugar musts. High osmotic pressure can adversely affect the onset and health of the fermentation if the yeast is not correctly matched to the must. In my previous post I mentioned K1, 71B and Uvaferm 43. With the higher starting brix stick with Uvaferm 43 or K1, if you go to a lower brix like 24 71B will work well too. At 30 brix you are on target for an ABV of about 17%, if you want to go less that's fine too.
However, if you start out at 14 brix your ABV Potential is about 7.3% which is too low to inhibit other competitive bacteria and yeast that can overtake your fermentation and infect your batch. You should start at a minimum of about 24 brix which puts you at 14% ABV which will inhibit all but the heartiest spoilage bacteria. It is also necessary to encourage a fast fermentation as the naturally occuring yeast and bacteria in the agave syrup will also succumb to rapidly changing osmotic pressure and rising alcohol by volume.
3) When you talk about "lots of aeration" are you talking vigorous stirring or are you talking about O2 injection?
O2 injection is fine but I generally use a combination of O2 injection and stirring with a whip degasser or a lees stirrer. You want the must agitated and more importantly you want the yeast up in suspension as much as possible. This brings up another issue and that is highly clarified must. If your must is highly clarifed (i.e. low to no turbidity) you'll need to add yeast hulls in order to help your yeast stay in suspension. Add as per manufacturer's suggestion per wine musts. Aerate at least twice daily during the first phase of fermentation (up to the 1/3 sugar break) and then just stir so as not to aerate during the second third of fermentation. Use a lees stirrer or a long handled stirring spoon.
4) Your nutrient requirements make a lot of sense and go well with other suggestions I have heard, but what is the batch size you have in mind? They seem a bit light unless you are talking about a ~10 gallon fermentation.
These are modified Staggered Nutrient Addition (SNA) schedules I use when making certain honey musts and when I've made agave must. Using more will leave a salty/metallic flavor in your finished product in my experience. This is my generally used addition schedule for 6 gallon batches and is in accordance with recommendations from Lallemand and Scott Laboratories.
4) I will be getting the yeast brought up from the dry culture by a friend of mine in her microbiology lab. When you pitch, are you pitching 500mL of slurry, 1L of slurry or what? And again, what is the batch size you have in mind?
I'm generally pitching 12 grams of yeast rehydrated in 100 ml of H20 at 111 F. It is very important to follow the Go-Ferm yeast rehydration process exactly or all bets are off. Once the temp is down to 104 F add your yeast, stir and let sit for 15 minutes and stirr again. Then add an equal amount of your agave must, stir and then add that the mixture to the rest of the must. If you're building a 2 liter starter do the same thing with the starter and let it get going good and strong before you pitch. This is for a six gallon batch.
I STRONGLY recommend against using a slurry from a friend unless you've specifically used it in agave musts. Agave is notorious for becoming stuck or undergoing a slow and protracted fermentation which is not desireable. It costs less than $10 for the Go-Ferm, Active Dry Yeast (K1 or UvaFerm 43) Fermaid-K and DAP to do this with proven yeast strains and nutrients. Why risk the investment $$$ with an unknown even if it is coming from a microbiology lab?
My .02,
Oskaar
Last edited by Oskaar on Thu Jan 17, 2008 3:52 pm, edited 1 time in total.
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Become a Brewer's Hardware Fan on Facebook!Derrin speaks the truth, you are the lead authority on everything yeasty! (well, maybe brewing yeasts...) 
Anyway, one more follow-on question: If I am planning on doing both the raw sugar fermentation and the agave fermentation in roughly the same volumes, would it be feasible to do the raw sugar fermentation using K1-V1116 with the rehydration and the nutrition routines you have described in this thread, rack the fermented sugar solution off, then start the agave fermentation on the same yeast bed with some additional nutrition doses?
If so, would you suggest the nutrition doses be the same as you have described in this thread?
If it's better to do two completely different fermentations, that's cool with me, I just thought I would use the raw sugar fermentation as an enormous starter type thing.
Anyway, one more follow-on question: If I am planning on doing both the raw sugar fermentation and the agave fermentation in roughly the same volumes, would it be feasible to do the raw sugar fermentation using K1-V1116 with the rehydration and the nutrition routines you have described in this thread, rack the fermented sugar solution off, then start the agave fermentation on the same yeast bed with some additional nutrition doses?
If so, would you suggest the nutrition doses be the same as you have described in this thread?
If it's better to do two completely different fermentations, that's cool with me, I just thought I would use the raw sugar fermentation as an enormous starter type thing.
You're better off with two different fermentations. Wine yeast are made to ferment to dryness and then flocc. So using the cake would result in a slow or stuck fermentation.
I'd do the same nutrient dosing regimen for both. K1 will come out a bit hot with pure sugar, but I honestly don't know what yeast won't. You might try that with the Uvaferm 43 although I've not tried this wieh a pure cane sugar ferment. I'm sure it would do fine as long as the YANC is good at ferment onset and you supplement FAN with Fermaid K as above. Also with the sugar ferment you might go with 12-15 grams DAP in the must before you pitch.
Hope that helps,
Oskaar
I'd do the same nutrient dosing regimen for both. K1 will come out a bit hot with pure sugar, but I honestly don't know what yeast won't. You might try that with the Uvaferm 43 although I've not tried this wieh a pure cane sugar ferment. I'm sure it would do fine as long as the YANC is good at ferment onset and you supplement FAN with Fermaid K as above. Also with the sugar ferment you might go with 12-15 grams DAP in the must before you pitch.
Hope that helps,
Oskaar
Don't go into the Pimped-Out-Refrigerator Jack!