I recently finished my evaluation of CL23 for use with neutrals, so I thought I should share my opinions and observations.
Product Description: (see: http://vintnersharvest.com/collections/wine-yeasts) Quote:Saccharomyces Bayanus - Ideal for crisp, fresh dry white/blush and all sparkling wines. Also the best strain for high alcohol tolerance.
CL23 produces very low levels of fusel oils and other congener compounds during fermentation and so does not contribute much to wine flavour or aroma and can therefore be considered to be a particularly neutral / clean fermenter. However CL23 does contribute significantly to the wines structure and ferments out sugars completely allowing for the driest of wines to be made.
CL23 is noted for its robustness, being able to ferment to 18% abv. ethanol, tolerate high free SO2 and high levels of other stress factors such as organic acids, incorrect temperature and pH making CL23 the strain of choice for high alcohol wines or where uncertain recipes are employed and fermentation reliability is a key factor or where low temperature fermentation down to 8°C (46°CF) is required. This strain is "˜fermentation friendly" in that it produces zero foam, starts fermenting rapidly so avoids potential bacterial contamination and can be used to re-start stuck fermentations.
In certain situations, CL23 can be used for red winemaking - especially where wine structure and dryness are key factors - but a word of caution, CL23 will take out colour and fruit flavour so recipes should be adjusted accordingly. To appreciate such attributes, split a Cabernet Sauvignon Must and ferment out using CL23 versus VR21 - you will not believe both wines came from the same grape.
CL23 is also available in a 100g pack suitable for 300 litres.
The Wash and the Process I had trouble making up my mind about which recipe to use but settled on Birdwatcher's as it is so very basic, neutral and reliable.
I prepared two identical washes, in sequence. The second wash was started after I racked the first to the boiler for stripping. As luck would have it, the weather changed so the fermentation temperatures were about 5 C lower for the second wash. Both washes were individually stripped. The low wines were then combined for a total of 10.5 L
48.3%. The low wines were dilluted to 40% for a single spirit run in a fully packed PSII HC.
With baker's yeast, the aroma of my low wines is usually dominated by the tails. I'm very sensitive to tails and I consider the aroma disgusting. Not so with these two washes, which is probably the only reason I even noticed. Even though I brought it down to 20% (or slightly less) the aroma was still somewhat light and a little fruity with just a hint of tails. Not that this matters much WRT final product, but it suggested that there might have been less fusel production than I would normally expect.
[table="width: 500, class: grid, align: center"]
[tr]
[td][/td]
[td="align: center"]
Wash 1[/td]
[td="align: center"]
Wash 2[/td]
[/tr]
[tr]
[td]OG[/td]
[td]1.080[/td]
[td]1.080[/td]
[/tr]
[tr]
[td]FG[/td]
[td]0.992[/td]
[td]0.994[/td]
[/tr]
[tr]
[td]Avg. Temp (C)[/td]
[td]20[/td]
[td]15[/td]
[/tr]
[tr]
[td]Primary (days)[/td]
[td]17[/td]
[td]20[/td]
[/tr]
[tr]
[td]Secondary (days)[/td]
[td]10[/td]
[td]7[/td]
[/tr]
[tr]
[td]Clarity[/td]
[td]Crystal clear[/td]
[td]Crystal clear[/td]
[/tr]
[tr]
[td]Color[/td]
[td]Dull Yellow[/td]
[td]Amber[/td]
[/tr]
[/table]
The spirit run was slow and low after slightly more than an hour of full reflux. I collected about 3100 mL at an average collection rate of just under 500 mL/hour. The aroma was pleasant and a just a bit fruity in all jars. I'll have to let this age for a month or so before I can provide my final opinion as to nose, pallette, finish.
Pros
- Instructions call for direct application (no starter) [I followed the instructions :)]
- Low fusel production
- High ethanol tolerance (meaningless to me and not evaluated)
- Flocculates very well
Cons
- A little pricey
- A bit finicky to start (should start > 20 C)
- Needs to be stirred a few times
Overall, I thought this yeast would be worth a second round. The jury's still out as to the apparent ester production ... I'll check after some aging. Fusel production definitely seems lower based on what I normally detect (via nose) in the my low wines ... and there was only the slightest hint of fusels even towards the end of the spirit run. It clears extremely well: the remaining sediment in the secondary seemed like it was sticking to the bottom ... so racking was a yawn (just the way I like it!). And lower temps don't seem to affect performance much (maybe a good winter yeast).
Anyway, more to follow once the aging is complete.
Regards,
--JB
