Lacto Shelf Life

I saved a bottle of pure Lacto from my last sour wort starter. How hearty is Lacto? Will it still be viable after six months at room temp in sealed swingtop?

Based on my experience it should be just fine, but I'd recommend doing a starter with it. I'd start out with a liter of 1.020 starter. Taste it after a week and make sure it's souring. Skip the stir plate and even purge with CO2 if you can.

You should expect a 15% loss in viability for each month of room temperature storage. In other words, after 6 months, you will have mostly dead cells.

As microbusbrewery mentioned, you should be able to revive the remaining viable cells in a starter. If you throw in a few ounces of apple juice, the cells will do much better.

Jumping on to the end of this older thread since it was the first hit on my search...

I'm planning on brewing a Berliner Weisse style beer (Kottbusser) next month sometime, so ordered some Lacto delbrueckii, as per the recipe I'm going to use. I get 90% of my supplies & ingredients online from one regional HBS that I've been very happy with. Received the order today, and the White Labs Lacto. delbrueckii vial is labeled best by 1-21-2020. I was assuming it would have a shelf life like yeast, but have never used or ordered bacteria before, so maybe my expectations are out of line? I checked the White Labs Yeastman lot QC and it says best by 3 -21-2020. So which is correct? Should a request a newer vial from the online retailer? Should I just not worry about it and make a starter (which I've not researched yet for Lacto starters - the recipe I'm working from just says to pitch some Lacto delbrueckii along with the Kolsch yeast). TIA for your thoughts or suggestions.

Hellbender1 said:

Lacto delbrueckii

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Do yourself a favor and use Lactobacillus plantarum.

Also take a look at my suggested method for fast souring:
https://www.homebrewtalk.com/forum/threads/fast-souring-modern-methods.670176/

Cheers

I have no idea which expi date would be correct. I’d shoot an email to White Labs. A possible explanation on the difference could be due to FDA regs if packets of Lacto are included in such a thing. FDA might require 1 timeframe for the package while White Labs might suggest a 2nd date (based on something else, maybe research) with the caveat that it is intended for brewing and not immediate consumption. Or maybe the stamper just wasn’t set correctly that day. Or maybe Fred hit 3 instead of 1 on the computer. This is all speculation and I’d love to hear what White Labs would say.

I would still just use that packet as-is for your brew day. I know that slurry has a lot of Lacto in it compared to a packet but I have used small amounts of very old slurry, that set at room temp to make sour bombs.

+1 on reading Fast Souring if you haven’t already.

RPh_Guy said:

Do yourself a favor and use Lactobacillus plantarum.

Also take a look at my suggested method for fast souring:
https://www.homebrewtalk.com/forum/threads/fast-souring-modern-methods.670176/

Cheers

Click to expand...

Thank you for the tip on the Lacto species - I'll give it a try!. Your post for fast souring looks fantastic. Thank you for the help!

Funky Frank said:

I have no idea which expi date would be correct. I’d shoot an email to White Labs. A possible explanation on the difference could be due to FDA regs if packets of Lacto are included in such a thing. FDA might require 1 timeframe for the package while White Labs might suggest a 2nd date (based on something else, maybe research) with the caveat that it is intended for brewing and not immediate consumption. Or maybe the stamper just wasn’t set correctly that day. Or maybe Fred hit 3 instead of 1 on the computer. This is all speculation and I’d love to hear what White Labs would say.

I would still just use that packet as-is for your brew day. I know that slurry has a lot of Lacto in it compared to a packet but I have used small amounts of very old slurry, that set at room temp to make sour bombs.

+1 on reading Fast Souring if you haven’t already.

Click to expand...

I did check with White Labs and they emailed me a copy of the report with a 1-21 date on it. The online public report definitely is showing me 3-21; must be a bug (no pun intended).