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etisdale · 01-02-2010, 12:57 AM

Hi, All. Just bottled some pear wine I made using pear juice concentrate.

Based upon the original specific gravity (1.112 at about 72 °F), I should have ended with a pear wine having an ABV of 14.9%; instead, I have a wine that is 12.3% ABV (final gravity of 1.020 at 72 °F). The montrachet yeast that I used, according to what I have read, should be able to produce a wine having 15% ABV.

I fermented between 65 and 70 F and gave the yeast plenty of nutrients (i.e., I used Go-Ferm during rehydration, and Fermaid-K at a day after inoculation and at about 50% fermentation). The must had a total of 65% acidity, should that have any bearing on completeness of fermentation.

About 2.5 months have passed between start of fermentation and bottling, and the wine is super clear. It's good too, for being so young. It will definitely be consumed as a desert wine.

Since I am sort of new to this, I am trying to understand why the yeast did not ferment to their theoretical limit of 15% ABV. Any ideas?

Thanks!

impatient · 01-02-2010, 01:15 AM

Quote:

Originally Posted by etisdale

Hi, All. Just bottled some pear wine I made using pear juice concentrate.

Based upon the original specific gravity (1.112 at about 72 °F), I should have ended with a pear wine having an ABV of 14.9%; instead, I have a wine that is 12.3% ABV (final gravity of 1.020 at 72 °F). The montrachet yeast that I used, according to what I have read, should be able to produce a wine having 15% ABV.

I fermented between 65 and 70 F and gave the yeast plenty of nutrients (i.e., I used Go-Ferm during rehydration, and Fermaid-K at a day after inoculation and at about 50% fermentation). The must had a total of 65% acidity, should that have any bearing on completeness of fermentation.

About 2.5 months have passed between start of fermentation and bottling, and the wine is super clear. It's good too, for being so young. It will definitely be consumed as a desert wine.

Since I am sort of new to this, I am trying to understand why the yeast did not ferment to their theoretical limit of 15% ABV. Any ideas?

Thanks!

Most likely the yeast was not able to convert everything. I am not sure if everthing in pear juice concentrate is totally fermentable. The yeast may only know the answer to this.

**Wade E** · 01-02-2010, 03:29 AM

All the charts I read say 13% abv tolerance for Montrachet and those are just approximates. Why so high an abv for a fruit wine? I usually dont go beyond a starting SG of 1.090 on most fruit wine with the exception of Elderberry, Blackberry and black Currant. Those can hide a bigger abv.

etisdale · 01-02-2010, 03:35 PM

Quote:

Originally Posted by Wade E

All the charts I read say 13% abv tolerance for Montrachet and those are just approximates. Why so high an abv for a fruit wine? I usually dont go beyond a starting SG of 1.090 on most fruit wine with the exception of Elderberry, Blackberry and black Currant. Those can hide a bigger abv.

If 13% ABV is the norm, then I suppose 12.3% ABV is not such a mystery.

Incidentally, this is where I read that the tolerance of Montrachet was 15%: http://www.homebrewit.com/wineyeasts.php

Perhaps Montrachet can give a 15% ABV using certain techniques, for example, feed then starve then feed, etc.

As for the high original gravity, it wasn't exactly planned for. Still learning. Thanks!

Hinermad · 01-02-2010, 03:47 PM

Quote:

Originally Posted by etisdale

If 13% ABV is the norm, then I suppose 12.3% ABV is not such a mystery.

Incidentally, this is where I read that the tolerance of Montrachet was 15%: http://www.homebrewit.com/wineyeasts.php

Jack Keller's description of Montrachet (here) supports the 13% figure, but also indicates that it can get stuck in high sugar concentrations (above 23.5 Brix or about 1.099 SG).

Dave

david_42 · 01-02-2010, 03:56 PM

Fermentis says "Good alcohol resistance (till 15% vol.)".

outdoorsmadness · 01-02-2010, 07:39 PM

i just bought some montrachet yeast today at lhbs, which i wanted cotes de blanc for my strawberry wine but they dont carry it(m******f*s) so they told me most people use montrachet on fruit wines and told me that it useally dont go much more than 10%, but i made a blackberry with it that went 12.5%.