Anyone use R-HST?

[RPh_Guy]

I have this yeast fermenting a 1 gallon pseudo-ice cider (O.G. 1.140).
It's been bubbling along now for 8 weeks in primary.

Is this a strain I need to get off the lees or is it safe to leave it in primary?

Thanks

 

[RPh_Guy]

I mean, it's not normal to still be actively fermenting at 8-9 weeks, right?

It started in the low 50s, then ramped to mid 60s. I bumped it up to 70F a few days ago.
I pitched 8g in 1 gallon with no nutrient.

I'm afraid to do something wrong. It smells AMAZING.

 

[jgmillr1]

Temperature is certainly a factor in the rate of fermentation and it will take longer at lower temps. Sufficient nutrients can also help it to complete within a reasonable time. But I've also heard of some wineries in Michigan letting their Riesling ferment at low temps for months. The lower temps helps preserve volatile esters in the wine. Temperature tolerance varies with the strain of yeast as well as the aromatic by-products generated at different temperatures. I have no experience with R-HST however.

Your OG was somewhat high for many strains to ferment dry. How far along is it? What is the current SG?

 

[user 246304]

Temperature is certainly a factor in the rate of fermentation and it will take longer at lower temps. Sufficient nutrients can also help it to complete within a reasonable time. But I've also heard of some wineries in Michigan letting their Riesling ferment at low temps for months. The lower temps helps preserve volatile esters in the wine. Temperature tolerance varies with the strain of yeast as well as the aromatic by-products generated at different temperatures. I have no experience with R-HST however.

Your OG was somewhat high for many strains to ferment dry. How far along is it? What is the current SG?

JG, I really don't know anything yet. Is there any correlation between fermenting cool and preserving acid, as in growing cool?

 

[jgmillr1]

Is there any correlation between fermenting cool and preserving acid, as in growing cool?

Cool fermentation shouldn't impact acid preservation in a major way, as far as I'm aware. Some strains of yeast (eg 71B) are chosen since they metabolize more malic than other strains. Since the yeast action is affected by temperature, it is possible that fermentation temperature could modulate the acid levels indirectly though the yeast. On the whole though, some acid is consumed during fermentation but most is left in solution. I'll see maybe up to a 0.5g/L drop in TA with fermentation.

Looks like a nice yeast. I'll have to check it out when I have time to let the brew tie up a tank for a month (or two).

 

[Albionwood]

I've used R-HST in a standard cider. It worked fine but the result wasn't as good as I get with D47, so I never tried it again. I don't remember how long I left it on the lees (will check my notebook later), but in general, I leave ciders in primary until they drop the yeast out, then rack off for extended aging and clarification. When you see the cider clearing up, it's time to rack; but that's also temperature-dependent. In the 50s you can leave it on the lees for a long time; in the 70s you better not.
With your high starting gravity and cool fermentation temps it is not at all unusual for fermentation to continue for several weeks. Raising to 70F is not recommended, just let it continue at a slow pace and preserve those esters.

 

[RPh_Guy]

I haven't checked gravity in a while.
I guess I'll back down the temperature a little and leave it alone.

 

[RPh_Guy]

Current gravity is 1.060 ... dropped 80 points in 65 days.

 

[Albionwood]

You're at about 10.5% ABV then. What makes it a "pseudo-ice cider?"

 

[RPh_Guy]

"Ice Cider" is made by pressing frozen apples (cryoextraction). Anything besides this isn't a "real" ice cider, at least according to the Canadian government.

Homebrewers who can't easily execute that process could still freeze water out of fresh juice (cryoconcentration) for a similar effect.

The process for the must I used is basically the worst, concentrating through boiling (reduction) -- which is how FAJC is normally made from what I can discern.

It still looks like it's fermenting. I just ordered some glass marbles, sulfite & sorbate. Not sure if I'll use sorbate but I do want to prevent oxidation with sulfite. I also plan to add a bit of oak.

The newer abv equation would calculate that as 12.8% ABV, which I believe more.

I used R-HST because it's recommended for ice wine and was suggest by a fellow HBT member. It certainly appears to be well behaved so far, especially considering I didn't give it any nutrients.

 

[RPh_Guy]

In case anyone cares...
Sat in primary 5 months. No off-flavors. Tastes fantastic!