Lacto starter w/ Apple Juice - Question

I don't have an answer for you, but I'm definitely interested in following your progress. Are you willing to share the recipe/steps you'll be utilizing for this brew?

 

Maybe consider topping the container up with enough water to overflow, then cap with no headspace??

Pretty sure keeping the O2 out is muy important.

 

Interesting. Whenever I've read about using apple juice for a starter, the poster was talking about brett, but lacto grows well at low pHs (less than 5.0) so I think you'll have good luck with this. I have a lacto starter (Cascade dregs) going right now... the biggest key is temperature. Keep it at ~100F. This starter took off much much quicker than the last one I did at 70F. 7-10 days should be fine. Keeping O2 out is more important when you pitch the bacteria in your final wort, and not as important in the starter. If O2 is present, you can end up with butyric acid (smells/tastes like vomit), but this will go away over time.

 

Have you considered using a hot plate of some sort?

 

http://www.reptilebasics.com/flexwatt-heat-tape

I ended up getting two of these for a heat source. Crazy cheap.

 

Just keep it in your oven with the "Proof" function on.

 

... for 7-10 days

 

I would not do this, I've cultured a couple of strains in fruit juice and maintained with and without table sugar. Apple is a bad choice. It will get dry and will negatively affect the beer. I have had no luck with some serious effort. I can only tell you to no use apple. Fig juice was decent in the sour I made last fall.

 

I would.

 

Guys,

Firstly, make sure your lacto is a pure culture. Meaning, don't waste your time with yeast+lacto combo's. Yeast is easy to get, lacto is hard.

Re starter - there are a few tweeks you have to make. Starting lacto in apple juice works really well for the people that don't want to mess with beer starters and want something 'sterile'. As you step up your lacto starter all you need to do is drop out the lacto in the fridge, decant and change to a regular starter for your last step up. Bacteria do a good job going from hot to cold to hot. Not all the problems yeast might have. Make sure you shake (read stir) at ~200rpm.

Re heat - there are a few ways to do it. I like keeping my lacto starters around 42C or so. You can make it criminally difficult and try to do a heat belt, PID, etc etc. You can really try to make it regular difficult by putting it in the oven. Or you can do it simply and make a little hot box. All you need is a cardboard box tall enough to fit your flask and stir plate, coat the thing with foil on the inside and rig up a simple IR ceramic bulb for the inside. Just make sure the inside of the box stays at 40-44C. Regulate heat by cutting in some baffles.

Re time - 16 to 18 hours is when you want to step up or 'stop' your lacto. As long as you are at your temp and shaking speed, this is no problem.

Re amount of lacto - here is the problem that everyone runs into that no one talks about. Getting the right number of bacteria is important. Unless you have a spectrophotometer to measure, you are pretty much on your own. Here is a simple way to estimate that is absolutely full of holes but for the average dood to be able to get an idea...yes, math is involved.

Calculating theoretical growth for bacteria is pretty simple. Lets say we are using a Wyeast back of L. del, into 500ml starter @ 42C & 200rpm for 16h.

Wyeast 100ml smack pack = ~1.0E10 bacteria (10billion)

2^(Y generations) x # of starting bacteria =X # bact after Y generations

Y generations = time/ generation time

The generation time for L. Delbruickii = ~2.15hours

16h / 2.15h = 7.44 generations

Now plug and chug...

2^(7.44 generations) x 1E10 starting bacteria = ~1.74E12 bacteria @ 7.44 generations in 16 hours

Seeing that you need about 5:1 bacteria to yeast and you need 7E10 yeast for a 5gal Berliner weisse it goes like this.

1.74E12 bacteria/ 7E10 yeast = 4.97:1 or close enough

This is all theoretical but pretty close even if you don't have optimal growth media. Now the most important thing is to make sure your bacteria can get the beer sour enough...and that is 100% strain specific.

Cheers

Kristen

 

hahahah np!