raisin wine

[Ohio Bob]

That should be perfectly fine. I believe the suggested maximum is 18 F difference. You only have a 4-6F difference.

 

[winemaker81]

Brian, I have been reading about your overnight starters for quite sometime now and I am a little reluctant to try the overnight method. I usually brew one six gallon batch at a time with a heat belt around the fermenter because my basement is 68F. I like to pitch with a must temperature of 72-74F. If I place my yeast starter next to the fermenting bucket, it would be much colder than the must temperature. Is it acceptable to pitch a colder starter into a warmer must?

From what I've read, any significant temperature difference can produce problems, and your differential will be 4 to 6 F, which is not (IME) that much. I have a few ideas:

1) since the must temperature is warmer than the starter by a bit, I suspect that will be less of a problem, so it should work fine.

2) How warm is your kitchen? If the temperature is within a few degrees of your must, then keep the starter in the kitchen before inoculating.

3) Don't use the belt initially, applying it after you have inoculated. Consider that most of my ferments are in the 63 to 67 F range, which is colder than your basement, and I get great results. You're happy with your procedure so I'm not suggesting changing it much but applying heat after inoculation avoids the temperature differential,.

 

[wineview]

From what I've read, any significant temperature difference can produce problems, and your differential will be 4 to 6 F, which is not (IME) that much. I have a few ideas:

1) since the must temperature is warmer than the starter by a bit, I suspect that will be less of a problem, so it should work fine.

2) How warm is your kitchen? If the temperature is within a few degrees of your must, then keep the starter in the kitchen before inoculating.

3) Don't use the belt initially, applying it after you have inoculated. Consider that most of my ferments are in the 63 to 67 F range, which is colder than your basement, and I get great results. You're happy with your procedure so I'm not suggesting changing it much but applying heat after inoculation avoids the temperature differential,.

All good suggestions. The reason I am using the belt today, is because I’m making a DB from frozen blueberries. After adding cold water and blueberries, the bucket was 55F and I felt I needed to raise that temperature. I was under the impression that a 10 degree difference isn’t a big deal and better to pour a cold starter into a warmer environment. Less shock for the yeast?

 

[winemaker81]

All good suggestions. The reason I am using the belt today, is because I’m making a DB from frozen blueberries. After adding cold water and blueberries, the bucket was 55F and I felt I needed to raise that temperature. I was under the impression that a 10 degree difference isn’t a big deal and better to pour a cold starter into a warmer environment. Less shock for the yeast?

I haven't read anything firm on the subject, but my impression is that 10 degrees F difference between the starter and the must could cause shock. I don't have a certain answer on how much is too much, so I get it as close as possible.

Given my experiences, once the must hits 62 F it's good for inoculation, although if your cellar is 68 F, I'd let it warm up to cellar temperature first.

 

[wineview]

I haven't read anything firm on the subject, but my impression is that 10 degrees F difference between the starter and the must could cause shock. I don't have a certain answer on how much is too much, so I get it as close as possible.

Given my experiences, once the must hits 62 F it's good for inoculation, although if your cellar is 68 F, I'd let it warm up to cellar temperature first.

I’ve never been 10F off it’s something I read along the way but alway targeted a perfect match. I was surprised to read Ohio Bob’s response of 18F.

 

[winemaker81]

I’ve never been 10F off it’s something I read along the way but alway targeted a perfect match. I was surprised to read Ohio Bob’s response of 18F.

Yeast can be surprising due to variations in how a given batch grows.

For me, it's risk management. By ensuring the starter and must temperatures are close, I eliminate a potential problem with minimal effort.

 

[wineview]

Update. Pitched the starter this morning. Starter temperature 70* must temperature 70*.

 

[Ohio Bob]

I’ve never been 10F off it’s something I read along the way but alway targeted a perfect match. I was surprised to read Ohio Bob’s response of 18F.

According to Lallemand, “To minimize cold shock, ensure temperature changes are less than 10C (18F). It is recommended that juice/must be inoculated no lower than 18C (64F).”

This seems to be a wide range, and probably manufacturer safety factors thrown in. For example, I once pitched a white around 60F and it worked out well.

 

[winemaker81]

According to Lallemand, “To minimize cold shock, ensure temperature changes are less than 10C (18F). It is recommended that juice/must be inoculated no lower than 18C (64F).”

Huh. That seems way too wide a variance, but I'll trust the vendor's description for their yeast.

That said, I'll keep using my method as it works, and it's possible other vendor's yeast may not be so open.

 

[Ohio Bob]

That said, I'll keep using my method as it works, and it's possible other vendor's yeast may not be so open

Totally agree. I follow your yeast starter protocol, and put the starter next to the bucket of must to acclimate for 12 hours or so. So my temperature difference can’t be more than 1 or 2 degrees.