Stabilization and yeast tolerance - an anecdotal tale

[MightyMosin]

If you read through this forum you will periodically see posts that state that they don't want to use chemicals or why should I stabilize? There are a variety of members on here that pasteurize to avoid using additions and they do so very successfully; I believe there is a pinned post on the cider forum about how to do this. For myself, I use the K-Meta and K-Sorbate to stabilize the mead and to prevent further fermentation.

I started a mead on 03/16/2023 with SafAle S-04 yeast. This yeast is tolerant to 9-11% according to the manufacturer. After ~ two months it stopped at 1.004 SG with an estimated ABV of 13.65%. I wasn't surprised by this as I have previously used the ~11% yeast and have gone to 14%.
What I was a bit surprised by is that it didn't finish dry, but it was over tolerance.

I stabilized the mead with K-Meta but no Sorbate and I back sweetened it to 1.019 and left a comment in my notes that said "will fermentation start?". That mead has sat in the carboy for about 17 months since and I finally circled back to it as I'm trying to get a bunch finished out for the end of the year. I racked and checked it today. The pH was the same at 3.6 and the SG was sitting at 1.006. It had obviously started fermenting again once the condition (probably temperature) were more favorable to the yeast and it went through most of that added honey and then finally tapped out. It is now at a calculated 15.36%, but with the added honey volume I'll round that down to 15%.

None of this is new for me, but the takeaways from this:

• Published yeast tolerances are just rough guide lines and the yeast are horrible readers and if well fed they will go above and beyond for you.
• If you are trying to game where a yeast will stop based on published tolerances, be prepared to be disappointed in either direction of that tolerance, though it will usually exceed published tolerances based on my experience if you provide the nutrients that mead needs.
• I purposefully did not use K-Sorbate at the first racking as I was pretty sure that the yeast would start up again. If I had, it probably, but not assuredly, would have stopped where it was at.
• I've seen a few posts where some members have used only the K-Sorbate without the K-Meta; that is setting up the potential for bacteria that might use the sorbic acid as food and ruining your mead. Always use K-Meta if you will use K-Sorbate.
• If I had trusted that fermentation was done at that 1.004 and bottled without the use of K-Sorbate and only used the K-Meta, every single bottle would have exploded violently.
• At this point, even though I am confident that the yeast has tapped out at >15% ABV I am still using stabilizers as there is still sugar left there. I will almost certainly add some more honey in to back sweeten next week and those stabilizers are my long term insurance against a super yeast strain that might continue higher, even though unlikely at this point.
• Pick your poison for mead stability: ABV tolerance tap out, chemical stabilizers, or pasteurization... but pick one to use.

I use chemicals for stabilizing as ABV tolerance means three general paths: to take:

• A dry mead that has used all the honey up and you don't add any honey after. This can be any ABV. A nice dry traditional mead fits well here.
• A high ABV that has used all the honey it can and you can now back sweeten with honey to get the flavor you want. Not a bad approach, but I do enjoy the carbonated session meads that use honey as the sweetener. I also don't want all my meads to be a high ABV.
• A dry mead that used all the honey and you back sweeten with a non-fermentable sugar. A good approach but you have to find a sweetener that you enjoy. I want honey as my sweetener to help keep/enhance that aspect.

For myself, I haven't tried pasteurization. It it more work than I want to entertain at this point and I am leery of what those higher temperatures may do to the flavor, though I don't really know as I haven't done it yet.

 

[bernardsmith]

Here's the thing about yeast specs: They are very similar to the specs that manufactures of project critical hardware publish - think, chains, ladders, ropes, elevators, and the like. If a manufacturer states that the weight an elevatorr can take is 400 lbs, you KNOW that it MUST take more weight before it will break. BUT if you enter an elevator and te load is 401 lbs and it crashes 20 floors ... You and not the manufacturer is responsible. On the other hand, if you NEEDED that elevator to crash when it carried 450 lbs and it worked perfectly, again, you and not the manufacturer is to blame Labs are merely telling you the most conservative specs that THEY will take responsibility for when the yeast FAILS.
On another note, pasteurization, in my opinion is rarely if ever a good option. Sure, heat will kill the yeast, but it will also destroy volatile aromatics and flavor molecules, and you spent good money on honey and not table sugar for those aromatics and flavinoids. and that is the BEST scenario. The worst scenario is that the CO2 in bottles of mead will expand upon heating and unless the bottles are designed to withstand the pressure of that expanded gas, you may find that the heat creates bottle bombs. Here, the best case is that you lose only the contents of the bottles. Worst case, is that flying shards of exploding glass behave just like shrapnel.

 

[MxWhiskey]

For myself, I haven't tried pasteurization. It it more work than I want to entertain at this point and I am leery of what those higher temperatures may do to the flavor, though I don't really know as I haven't done it yet.

I don't know what temperature you would need to destroy flavor compounds, and inevitably there are some that will be lost at relatively low temperatures, but you can pasteurize at around 140-145 F. If you have a sous vide or a reliable way to hold water at a consistent temp, pasteurization just takes time.

That said, I also chem stabilize. It's just easier for me and I also don't know how much the flavor will change with doing that. Once I get a sous vide, I'll probably run that experiment.

 

[MightyMosin]

For me, pasteurization is just more work than I want to go through; I already dislike bottling and don't want to extend that time further. Maybe I'll do an experiment at some point with just a few bottles.

I have an immersion circulator that I use for the Sous Vide cooking method. I have another inexpensive one that I use to warm up honey about a week before I plan on starting new batches if they have crystalized.

 

[MxWhiskey]

For me, pasteurization is just more work than I want to go through; I already dislike bottling and don't want to extend that time further. Maybe I'll do an experiment at some point with just a few bottles.

I have an immersion circulator that I use for the Sous Vide cooking method. I have another inexpensive one that I use to warm up honey about a week before I plan on starting new batches if they have crystalized.

I completely understand, it's not something I do or even recommend. Sulfites are perfectly fine for me.

 

[Raptor99]

I have another inexpensive one that I use to warm up honey about a week before I plan on starting new batches if they have crystalized.

Would you mind sharing some details about how you do that? Decrystalizing honey is a pain.

Thanks!

 

[DannyJones]

I agree, yeast tolerances are more like guidelines they often push past their limits if conditions are right. Your points about stabilization are spot on too. Using both K Meta and K Sorbate together is key to avoiding surprises and I appreciate the reminder about the risks of using only Sorbate.

I also haven’t tried pasteurization for similar reasons I’m worried about how it might affect the flavor. I usually stick with stabilizers and back sweeten with honey, as it keeps the mead’s character intact.

 

[Dan O]

Would you mind sharing some details about how you do that? Decrystalizing honey is a pain.

Thanks!

I use my sous vide machine to decrystalize as well. I set it for 95°F & make certain to stir it really good daily. It will decrystalize a lot faster the more you move it around. Fully crystallized, I will run it until it's completely fluid again, sometime it could take over a week.
I hope this helps you.
Happy meading

 

[MightyMosin]

Would you mind sharing some details about how you do that? Decrystalizing honey is a pain.

Thanks!

It's about as simple as you might think. I get a plastic tub and put my bucket/container of honey into it and then fill the container with hot water from a bathroom tub. Sometimes I need to put a weight on the honey container to keep it from bobbing and tipping over.
Hook the immersion circulator to the side of the plastic tub, set the temperature (I usually use about 99F) and let it go.

Every couple of days top up water, as needed. I usually do this at least a week before I need it. If the crystallization is bad, make that about 2 weeks before needed. You can help the process along after you get some of it liquidized by stirring the honey around to mix it up as the edges will get liquid before the center.

 

[bernardsmith]

Here's another very simple and very quick method of dissolving any honey in water or juice. I add a cup or so of the water I intend to use to my blender, which I have sanitized in Starsan, and then add a batch of the honey and blend. This mixes the honey and aerates. . Repeat, dumping the mixture into the fermenter until all the honey is mixed with the water and is in the vessel. Voila! Mixed effortlessly and aerated with the same amount of no effort.

 

[MightyMosin]

Nice tip. Might try that one out!

 

[bernardsmith]

The one minus, is that the solution has a great deal of froth that takes hours and hours to dissipate. So, if you are skeptical of the SG and want to measure it before pitching the yeast, you may have a long time to wait. But if you treat honey as typically increasing the gravity of water by 35 points in a total volume of 1 US gallon, then that downside is less a problem than simply something to note. And if your primary fermenter is a bucket with lots of headroom, it's even less of a concern.

 

[MightyMosin]

Good caveat to know