Gravity

[Spring_Chicken]

Do Lacto, Pedio, and Brett kick off alcohol in a fermentation? I'm making a beer that I'm starting on Lacto, and the gravity has fallen significantly while it's souring, but is that going to translate to ABV?

 

[Nateo]

Lactic acid = 1.209g/cm^3, ethyl alcohol = 0.789g/cm^3. Water is 1g/cm^3. So the Lactic acid is about twice as dense as alcohol, and a lot denser than water. It's possible the Lactic bacteria is making alcohol as well.

 

[othellomcbane]

Brett is a yeast and definitely produces alcohol.

 

[Spring_Chicken]

Lactic acid = 1.209g/cm^3, ethyl alcohol = 0.789g/cm^3. Water is 1g/cm^3. So the Lactic acid is about twice as dense as alcohol, and a lot denser than water. It's possible the Lactic bacteria is making alcohol as well.

How will this effect a hydrometer reading?

 

[ryane]

How will this effect a hydrometer reading?

It wont, gravity is gravity, but it can affect your abv calc because rather than turn into alcohol those sugars are lactic acid, but who really cares about that anyway?

 

[Spring_Chicken]

It wont, gravity is gravity, but it can affect your abv calc because rather than turn into alcohol those sugars are lactic acid, but who really cares about that anyway?

It's nice to know roughly what your ABV is... Especially if one ever intends to go pro.

I'm more concerned with the hydrometer in the sense that if it's denser it will move the hydrometer up higher, making it look like there is more sugar and solution than there really is. That may end up making it so that my yeast have nothing left to eat even though I think that they do.

 

[ryane]

It's nice to know roughly what your ABV is... Especially if one ever intends to go pro.

I'm more concerned with the hydrometer in the sense that if it's denser it will move the hydrometer up higher, making it look like there is more sugar and solution than there really is. That may end up making it so that my yeast have nothing left to eat even though I think that they do.

that listed value is for 85% lactic acid, when its more diluted it will be much lower. We could easily figure it out to see what a more reasonable density in water would be, I remember it being around 1014 or 1020 at a level you would see in beer

 

[Spring_Chicken]

that listed value is for 85% lactic acid, when its more diluted it will be much lower. We could easily figure it out to see what a more reasonable density in water would be, I remember it being around 1014 or 1020 at a level you would see in beer

I have no idea what that means.

My beer started at 1.040, and I'm letting it sour for a week on straight Lacto, then I'll boil the wort and add hops etc, now it's down to 1.024. Does that mean that it's actually lower?

 

[spenghali]

Even the traditional ABV equations aren't accurate, your whole world is lies, all lies!

 

[Spring_Chicken]

Even the traditional ABV equations aren't accurate, your whole world is lies, all lies!

I knew it! The politicians have even gotten to my hydrometer and now it's corrupt. How very 1984. 2+2=5, right?

Seriously though, I should be able to use it to guess at how much sugar is left. Maybe I could let it eat a sample all the way down and use that information calibrate my hydrometer next time? Will Lacto eat 100% (or thereabouts) of the sugar?

 

[spearko520]

drink a dozen of them and then divide your drunkenness by 8. if you are 100 percent drunk, then they are 12.5 percent... i know it seems counter-intuitive, but the math works. i read a book about kurt godel once, and i think it was in the bibliography...

 

[Spring_Chicken]

drink a dozen of them and then divide your drunkenness by 8. if you are 100 percent drunk, then they are 12.5 percent... i know it seems counter-intuitive, but the math works. i read a book about kurt godel once, and i think it was in the bibliography...

I'd have to use the /2 factor in that and invite a friend. maybe a second opinion on the drunkenness. What are you doing Friday. Like all day?

 

[spearko520]

WA would be to far to drive home with my foot out the door so i don't crash. BUT maybe we could trade some bottles and i can give you my opinion... i will be drunk on friday, so i will have to factor that into my equation. hmm math minus, carry the one, denominator...