Conversion rates for Chardonnay

I’m curious what conversion ratio (sugar to alc, of course) you typically see for Chardonnay fermentations (barrel fermented). Have you seen a lower conversion for uninoculated fermentations than inoculated ones?

I’m expecting 0.60 or so…but wondering what your collective experience is.

Thanks!

I have seen .60 to .66 on uninoculated barrel ferments. With the average being .62.
Thats with Anderson Valley and Sonoma Coast fruit.

Thanks Joe.

But .66…wow! How is that possible? I understand how you’d get that with reds (e.g. shriveled berries giving more sugar during the ferment) but not with whites.

I’m not sure it matters, but are your numbers from whole cluster pressed or destemmed then pressed (which some possible soak time)?

I do brix reading from the whole cluster press juice to final ETOH. I assume that the .66 vintage had more Fructose that Glucose and gave a higher conversion it also went to .000 rs.

I actually have much lower conversions on open top with some whole cluster Pinot Noir and with the cool vintages of 2010 and 2011 no berrie shrivel was present. .52-.55 is the last 3 year range for PN.

Ladd Cellar Chardonnay???

That’s the plan…tho the ink isn’t dry yet. It’s likely to be from 40 year old vines west of Sebastopol. Looking forward to it. Woo Hoo!

I’m pretty sure that Glucose and Fructose both convert to Ethanol the same way…so don’t think higher Fructose would account for the higher conversion. At any rate, I’ll bump my assumption up to .62 (rather than .60 that I was assuming).

As I understand it alcohol yields vary on depending on many factors ( yeast strain, YAN, and evaporation during fermentation). I think it has less to do with variety of grapes and more with yeast strain and fermentation type. Here is an article talking about this.

Casey

Great pdf link Casey…really nice over overview of issues. Thanks very much!

Awesome news Eric!