Trying to make some session meads with stabilizing and fruit and not sure what happened.

[mav3r1ck]

I posted this on reddit/r/mead, but would like to see what you guys here think about this and can give me some suggestions/help. Sorry it's so long.
Thanks
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Hey guys, Having a few meads under my belt, I set out to make some session strength (around 5%) meads. Started out with making a 6 gallon traditional. Here is what I did (sorry it's so long)

Steps:

1. added almost 5.5lbs of a wildflower honey and then spring water until it reached 6 gallons in my sanitized 8 gallon bucket fermenter.
   
   
2. Using sanitized wine whip and drill, I carefully mixed it for awhile until I felt it was evenly mixed.
   
   
3. Floated sanitized hydrometer to get reading. From what I can tell it looked like it was about 1040.
   
   
4. From mead calculator online, I figured my SNA was 4.5g fermK and 8.8g DAP spread evenly over 4 additions. I then added my first weighed addition (1.1g K/2,2g DAP).
   
   
5. I also added some pectin emzyme (will be on fruit later).
   
   
6. using whip/drill mixed all into must.
   

7)Lastly I dumped in 2 packs of 71B. I was just going to do 1, but calculator recommended 2 packs. I normally rehydrate my dry yeast in ferm Go, but I was out of it, so they just went right in.

8) Closed it up and put it in my temp controlled ferm chamber where I am able to keep it at a steady 65F.

24hrs in took it out of chamber, opened up fermenter and using whip and drill carefully airated/degassed must for a few minutes. I let it settle and then floated hydrometer for measurement. Looked like 1030. I then added my second nutrient addition same as first. Mixed it in for a few minutes, then closed it up.

48hrs in Again opened it up, degassed like before and took measurement. Looked like 1020. Added third addition, mixed again and closed it up.

72 hrs in Like before, opened it, degassed and took measurement. Now down to 1003! Decided not to do last addition. Closed it back up.

96 hrs in Opened it up, degassed and took measurement once more. Reading .998 At this point I called it done, and I started warming it up slowly in my fermenter (this is a habit from homebrewing beer-D rest so yeast can clean up). I went 1 degree/day until it reached my basement ambient temperature of around 70 degrees.

1.5wks in I moved entire fermenter into my keezer to cold crash. Before doing so, I pulled off a sample for my hydrometer and gravity was still .998. Using a pH meter, I measured pH to be 3.1 (use this for stabilization below)

24 hrs into the crash I added gelatin to help drop some stuff out. I know gelatin isn't the best to use with mead, but it was all I had.

48hrs into the crash I prepared another bucket for stabilization. Using the pH reading, I measured out 0.53 grams of Potassium Metabisulfate (crushed campden tablet). Going off of the chart for Potassium sorbate, I used the lowest 10% addition of 3.79 grams/5 gallon but since I had 6 gallons I also measured another 0.76g (3.79/5) for a total of 4.55 grams. I added both of these amounts to some of the warm must and mixed throughly in a sanitized jar. I had no way of measuring Free SO2, so this is what I went with.

I then added that mixture to a new sanitized bucket and then took out the cold crashed must and immediately racked the cold must into the new bucket on top of the stabilized mixture and left as much of the yeast/lees behind in the original bucket. I then left that to sit sealed with an airlock on for 48 hrs at basement room temp. During that time I didn't see any activity.

Time to fruit into secondary. 6lbs of fresh blueberries from local farmers market that were cleaned and then bagged up and frozen. 6lbs of frozen organic strawberries from Costco.

I took both bags out of freezer, dunked in bucket of star san for a few minutes, then placed into another bucket to thaw. The next morning, I again sanitized both bags of thawed fruit, then using some clean/sanitized fine mesh bags, I added the fruit each to a bag. I then placed each back into a new clean/sanitized fermenter. I then racked out 1.5 gallon of the original mead into a sanitized 2 gallon carboy to later be back sweetened for a traditional mead. The rest of the mead (about 4 gallons) were evenly racked into each fruit fermenter. I sealed each up with airlocks and covered to protect from light. Now my plan is to let them sit on the fruit for a while (at least 2 weeks) and then slowly start tasting and pull fruit when I think they are good. I will probably have to backsweeten them and I will definitely have to backsweeten the 1.5 gallon traditional as I tasted it before stabilizing and it was very thin and dry tasting.

Here is where my problem comes in after adding fruit. 24 hrs in I open each one up and using sanitized spoon, move/push bag around to keep cap from getting moldly. 48hrs in same thing, no issues. 72 hrs in (last night) I open up strawberry and it is foaming inside like crazy! I am like WTF? It appears to be fermenting again. I panicked a bit and quickly moved the fruit bag around, sealed it back up and moved fermenter into my keezer. I then checked the one with blueberries and it was fine. Not taking any chances I also moved it into keezer. I just took both out of keezer to check them and move bag. Both were back to were they were originally. I put them back into keezer.

So my plan was to back sweeten and bottle all of this, but now I guess I will have to keg it all in some of my 3 gallon kegs. I am also not sure how the fruiting will work with them sitting in the keezer? Maybe I should just pull them out back to room temp and let the yeast do whatever (let them ferment it again and they will just be high abv melomels instead of the session ones I was hoping for). I would love to hear anybody's thoughts on this.

This was my first attempt and both stabilizing and making session meads. I would really love to hear from those with ideas/suggestions on where I may have made mistakes.

Sorry again it was so long, but I want to be completely clear on all my steps.

TLDR-thought I stabilized some mead, but some of it looks like it is fermenting again after doing fruit in secondary. Not sure where I went wrong, and what to do next.

 

[RPh_Guy]

Thanks for the details Saves asking a lot of questions.
First some hopefully helpful tips:

FYI when using raw honey unless you heat or chemically sanitize both the honey & water mead is "contaminated" right from the start with wild yeast and bacteria. Generally this doesn't matter. However it might matter if you like using 71B since 71B is susceptible to competitive factor and an aggressive wild killer strain could potentially cause a problem.
http://www.lallemandbrewing.com/product-details/lalvin-71b/

FYI DAP is toxic to yeast during rehydration. It would have been better to first rehydrate in filtered tap/spring water or to delay the first nutrient addition maybe 45 minutes. Maybe the DAP level is too low to matter, but I'd rather be safe. The sugar in the must is also toxic to rehydrating cells.

FYI I don't know what SNA calculator you used, but I like TOSNA 2.0 because Fermaid O is arguably better than DAP-containing regimens for several reasons. However if your process works for you, no reason to fix it I suppose.

FYI pectinase is best used with the fruit since it does not do anything in honey (it doesn't contain pectin). I'm not sure whether it will actually degrade before the fruit addition, but there's no reason to add it at the beginning. It doesn't work well when alcohol is present.

FYI it's often recommended to degas/aerate mead twice a day (or more) if you have the time. Keeps the yeast happy.

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All right, onward to the stabilization issue...

I measured out 0.53 grams of Potassium Metabisulfate (crushed campden tablet)

0.53 grams adds about 6 ppm total SO2 in 6 gal. You'd generally want a higher amount, around 50 ppm free SO2 for stabilization.
Assuming zero sulfite contribution from the 71B and targeting 50 ppm free SO2 in 6 gallons I get 4.75 tablets using
https://winemakermag.com/resource/1301-sulfite-calculator

FYI sulfite (molecular SO2 specifically) is used to inhibit bacteria (LAB specifically) and prevent oxidation (via free SO2). SO2 does NOT in any way stop the Saccharomyces we use for fermentation.
FYI Avoid molecular SO2 above 1 ppm in the final wine/mead to prevent off-flavor. Max legal limit in the U.S. is 350 ppm total SO2.

More reading:
http://srjcstaff.santarosa.edu/~jhenderson/Sulfur Dioxide.pdf

Free vs molecular SO2 calc: https://www.winebusiness.com/tools/?go=winemaking.calc&cid=60

48hrs into the crash.... Going off of the chart for Potassium sorbate, I used the lowest 10% addition of 3.79 grams/5 gallon but since I had 6 gallons I also measured another 0.76g (3.79/5) for a total of 4.55 grams.

4.55 grams theoretically adds about 180 ppm sorbic acid in 6 gal.
However sorbic acid solubility is drastically reduced at low temperature and should not be added to cold wine/mead.
Furthermore, sorbic acid solubility is drastically reduced at lower alcohol levels. Your mead is around 5.5% ABV, fairly low compared to most wine obviously.
300 ppm sorbic acid is considered the maximum (U.S. legal limit) so that's what I would use but I'm not confident it'll be soluble enough at such a low ABV to be effective (I can't find data).
Reading: https://irp-cdn.multiscreensite.com/78f98e39/files/uploaded/Stabilizing Sweet wines at Bottling 2018.pdf

FYI average tasting threshold is about 180 ppm, minimum tasting threshold is 130 ppm.

FYI Potassium sorbate is 74% sorbic acid by weight.

I took both bags out of freezer, dunked in bucket of star san for a few minutes

Yeast and bacteria are present throughout fruit. Dunking in StarSan does not sanitize it.

Sorbic acid prevents yeast replication, so it does not prevent continued fermentation if there is a substantial amount of yeast present. Therefore it cannot stop fermentation of non-sanitized whole fruit.

Generally speaking, to correctly sanitize fruit you either need to either:
1. Heat pasteurize (which should kill most everything depending on temperature and time except spores)
2. UV pastuerize the juice.
3. Sterile filter the juice.
These work for "sanitization" but not "stabilization":
4. Add around 50 ppm free SO2 (0.8-2ppm molecular SO2) after extracting the juice. This should inhibit/kill most wild yeast and bacteria... but not necessarily all the Saccharomyces present, so it may or may not stop fermentation even with sorbic acid with fresh fruit or fresh-pressed juice.
5. Making a puree and adding something like 100 ppm free SO2 may or may not work to kill wild yeast/bacteria. YMMV.

You also forgot to account for the volume of fruit juice when making any of the calculations for stabilization chemicals, so the sulfite and sorbate amounts were lowered below your [already low] targets when you racked onto the fruit.
Adding the fruit will also change the pH, throwing off the SO2 calculations.

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What to do now?
If you plan to bottle...
You could let them ferment at 65F. You might have some stressed yeast issues because of the sorbate present. It's not really possible to stabilize at this point while it's on fruit.

If you keep it chilled during flavor extraction and then rack, you have more options. Might need longer time on the fruit than usual.
Bottle pasteurization is a possibility.
It is possible with some yeasts to stabilize by repeated cold crashing and racking, (not sure about 71B specifically). And/or just try chemical stabilizing again with the levels I recommended.
Alternately you could sterile filter.
Or just keg and leave chilled until consumed.

Hope this helps.

 

[madscientist451]

I've found its best to keep things as simple as possible, the KISS philosophy....
So....Use heat to sanitize your fruit, OR:
To use "un-sanitized" fruit in a full strength mead, make a base mead first, as high ABV as possible, and when its done fermenting, rack on to the fruit. The alcohol in the mead will be diluted by the fruit, AND the fermentation will kick off again, but the ABV will still be high enough to kill wild yeast and bacteria found on the fruit.
For beer strength mead, the pro method is to again make the base mead first, but then use commercially available fruit puree that is made for beverage use and won't contain wild yeast or bacteria.
For tips on making session mead, search through the basic brewing podcast archives
and/or check out these videos:

http://www.groennfell.com/blog/category/videos