maple syrup mead/wine or acerglyn and amount of acid

Ingredients
1

I’m brewing a 100% maple sap/syrup wine and have a question about the amount of acid to expect in the finished product.

100% Maple sap was boiled down to produce an OG of 1.068.

This was sourced from a friend, who I asked to then keep as cool/cold as they could when they brought it to me to ferment.

I do not know the temperature or conditions under which the sap/syrup made it to me, but 2 days later I got about 5 gallons at
1.068 OG.  I mention this as I have a question about wild strain or vinegar progression…

I raised the temperature to 70F, pitched an activated WYeast 4184 Sweet Mead yeast to the must which had 3tsp foodgrade urea and amonnium phosphate added as yeast nutrient.

Fermentation was slow compared to my beers and ciders.  Took about 3 weeks.  Bubble rate in the airlock peaked at 1/7 seconds at day 2, 1/45 seconds at week 3.  Temperature mostly low 60s.

Fermentation was visibly done shortly thereafter, I finally racked to a secondary about 8 weeks total.  Cloudy and light straw color.

Gravity at that point is 1.010.  I expected a fuller fement, but am happy with the level of sugar.  The Wyeast says it is a sweet mead and the level of sugar is probably within style, but I’ve never used it before.

However, there is a good amount of acid in the brew, none added.  The amount of acid very nearly balances the amount of sweetness, so I’m happy with this, but…

Where did the acid come from?

My concern is that because I didn’t add any campden at the beginning, there may have been some wild strains.  Perhaps some vinegar.  Post fermentation there was a slight ring of fine grey/tan around the water line.

I’ve tried to read up on acid content of maple syrup, but have not found anything conclusive.  Several webpages do indicate
maple sap does contain malic acid, but I haven’t come across anything to give me confidence that that is the source of acid content.

So, my questions are…do you have any experience with 100% maple sap/syrup brewing?  Do they have a good acid content?  Do you think my brew has gotten an acid source from a wild strain?  If so, should I add some campden now, and then let it age/clear?

Thank you all for your help!

2

I brewed a maple wine several years back. It was around 1.150 OG and finished very sweet around 1.050. Frankly, the acid level was pretty low in the finished wine. This was early on in my mead brewing experience, and I wasn’t familiar with adding acid blend to the finished product. That’s a regret, because I think it could have balanced out the high sweetness level a bit.

It’s not really an apples to apples comparison with what you made, but I wouldn’t expect much acidity from the sap on its own. Contamination is certainly a possibility.

3

I’ve only done maple mead where I used maple syrup, honey, and maple SAP in place of water. I don’t think you would get much  acidity from maple sap and suspect infection. I would have held it at 160 for awhile before cooking to pitching temp.
Also, I’m not sure if this will have much flavor. Much of the flavor in maple syrup comes from the maillard reactions that occur once the syrup is thick enough to rise above regular boiling temp. Even that much more intense flavor is fleeting after going through the fermentation process.

4

I find real grade B maple syrup to have a very slight tartness, but nothing really worth mentioning.  If your maple wine is more tart than minimally so then I too would suspect possible contamination.  Either that, or perhaps since you sourced the sap and produced your own, it’s possible that where your maple trees are, the soil is more acidic than usual and is lending some terroir effects.

As pete mentioned above, I wouldn’t expect a lot of flavor out of this sort of maple wine either if it wasn’t boiled down to an amber syrup prior to fermentation.  How does it taste?  I’d be interested to hear.

I am intrigued by the idea and am considering making my own sometime.  I do like your choice of the sweet mead yeast, I think you did well using that yeast.

Cheers.

5

It actually tastes pretty good.

Slightly fruity and yeasty aroma (still cloudy).  Flavor noticebly sweet with an acid tang that is very evenly balanced between
the two.  There is a definite maple syrup flavor in the finish as well as mouthfeel.

I suspect the maple syrup flavor is from the boiling equipment.  They had run several batches of syrup to completion, and then as the final batch added in sap and boiled down to 1.068.  So residual caramelization from an earlier batch is probably the source of the good flavors.

I went and diluted some of their maple syrup and dipped some ph paper in it.  It came out pretty neutral, so I guess contamination is the source of the acid.

Thankfully it tastes nice!

I put some campden tablets in.  Any advice on how else to stabalize it?

Thank you.

6

I can see how residual syrup from previous batches added good flavors.  Cool.

In addition to the Campden, also add sorbate which is even more powerful at hurting the bad guys and preventing things from getting worse.

Glad it turned out to your liking.  Cheers!