Problems calculating ABV

[Mischka43]

Hello everyone.

I have owned a T500 for about 6 years, but until now only ever did sugar washes with Turbo yeast. Recently I started to make some better tasting things and really get into the hobby.
Here is my problem. I just put my first tomato paste wash into the still, but my ABV calculations are off.
I did the recipe as per the tomato paste wash calculator, 6kg sugar, tomato paste, epsom slat and bakers yeast in a 26L wash. I hydrated about 100g bakers yeast for about 2hrs, with lost of foaming almost overtopping my 2L jar several times.

Original gravity reading taken at 22 degrees was 1095. I let it ferment for 18 days and it bubbled away very nicely. I took the second reading again at 22 degrees after transferring into the boiler and stirring it to knock out all remaining CO2. Final Gravity came back at 920. So every calculator I find tells me that I have 22.97% ABV, which obviously can't be right since I am only using bakers yeast... Were am I wrong?

Thanks for any help
Cheers Felix.

[NormandieStill]

Final gravity will be probably 0.992, not 0.920. Should help with your maths!

[Yummyrum]

Final gravity will be probably 0.992, not 0.920. Should help with your maths!

That looks more like it

[Mischka43]

Final gravity will be probably 0.992, not 0.920. Should help with your maths!

So the ability to read a hydrometer seems to be somewhat of a requirement for brewing [emoji854][emoji1787][emoji1787]

Thank you kindly good Sir.

[NormandieStill]

Final gravity will be probably 0.992, not 0.920. Should help with your maths!

So the ability to read a hydrometer seems to be somewhat of a requirement for brewing [emoji854][emoji1787][emoji1787]

Not saying it's necessary, but it helps!

You're not the first person to stumble over this and I doubt you'll be the last. I've not made anything new for a while (other than for distilling where I largely don't care about the FG) so I'll probably have to remind myself next time as well.

[zed255]

Just a couple comments.

Bakers yeast can be far more capable than many people think. With careful management and good techniques a good bakers yeast (I like Fleishmann's) can reach as high a 16% ABV or there about. Not that should ever be a goal, pushing any yeast to its limit, due to the much increased congeners in a stressed ferment, but it is possible to go way beyond the point folks think it can go. I find about 10% ABV is a good upper limit for bakers yeast, giving a decent balance between yield and quality.

Your rehydration time was very excessive. Much past 20 minutes and the yeast are ready to feed and the viability actually begins to drop as they begin to cannibalize. You wouldn't have seen this with the huge amount you pitched. I use ~100g in a 200L ferment and that is still actually over pitching. A tablespoon, or about 10g, would have been sufficient in your volume. Rehydrate for 10 to 15 minutes and pitch.

[Salt Must Flow]

Curious. You said you hydrated your yeast for 2 hrs, it foamed, almost overtopping your 2L jar several times. Did you hydrate your yeast in warm water or did you add anything else to your water?

When I hydrate my yeast, I use 100F water, add yeast, I whisk until thoroughly blended and pitch after about 20-30 min. I don't recall it ever foaming up. It will foam if you add sugar though. No need to add sugar when hydrating and hydrating with sugar is said to have a negative impact on the yeast.

[Mischka43]

... I've not made anything new for a while (other than for distilling where I largely don't care about the FG) so I'll probably have to remind myself next time as well.

Until now I've done almost exclusively sugar washes with turbo yeast, So I never really cared about gravity. I knew that from 25L mash I'd get about 4.5L of alcohol. So I would cut 80ml foreshots, 400ml heads, the next 400ml I would use for mixing with rum essence, then 2500ml of pretty nice hearts which were Ok for Gin, another 400ml for Rum, and then 600ml tails.

So I never needed to take any readings.

But now I tried my first Birdwatchers so I wanted to get an idea of what to expect in terms of cuts. Btw the difference to a turbo wash is unbelievable, this stuff is so yum and comes out so clean! Call my a convert in terms of never using turbo again

[Mischka43]

Bakers yeast can be far more capable than many people think. With careful management and good techniques a good bakers yeast (I like Fleishmann's) can reach as high a 16% ABV or there about. Not that should ever be a goal, pushing any yeast to its limit, due to the much increased congeners in a stressed ferment, but it is possible to go way beyond the point folks think it can go. I find about 10% ABV is a good upper limit for bakers yeast, giving a decent balance between yield and quality.

I have to say I am more than impressed with the bakers yeast.

I was really dubious about using bakers yeast in a wash, thinking I would get a maximum of 5% ABV and wondered about the taste as well. Thats the reason I played around with the hydration (see below).

But the results are amazing. 14% ABV and the taste is great. I had to stop myself from sipping the wash

Curious. You said you hydrated your yeast for 2 hrs, it foamed, almost overtopping your 2L jar several times. Did you hydrate your yeast in warm water or did you add anything else to your water?

You are correct Salt , I added some sugar and DAB to get the yeast going. The water was also around 28C (82F).

You wouldn't have seen this with the huge amount you pitched. I use ~100g in a 200L ferment and that is still actually over pitching. A tablespoon, or about 10g, would have been sufficient in your volume. Rehydrate for 10 to 15 minutes and pitch.

The birdwatchers calculator said 70g for 25L. And I always go the "extra mile"

Your rehydration time was very excessive. Much past 20 minutes and the yeast are ready to feed and the viability actually begins to drop as they begin to cannibalize.

No need to add sugar when hydrating and hydrating with sugar is said to have a negative impact on the yeast.

Hydrating yeast or generally handling of yeast is something I definitely need to learn more about.
Thanks for your comments guys, it is really appreciated.

[howie]

i find that every time i hydrate bakers yeast, after about 15-20 mins, it will start to 'foam'.
that's just with 30-35C water and nothing else.
TBH i would only get worried if bakers yeast didn't foam.

[Olmatemick]

I see you like rum! Have a crack at a molasses wash mate, recycle the dunder a few times itll turn you off gin

[MiddleOfTheWorld]

get a refractometer, WAYYY easier to read in my opinion. (and they dont if they roll off the table)

[Mischka43]

I see you like rum! Have a crack at a molasses wash mate, recycle the dunder a few times itll turn you off gin

Hello Olmatemick, and thank for the comment

Rum is definitely my poison of choice and unfortunately an expensive one. I really enjoy a Rum that is at " drinking age" themselves .

I normally never drink Gin though, but when I tasted my home made stuff I actually really enjoyed it.

I have used the still spirits mixers for dark rum for a few years, but since the beginning of the year I am making my rum from molasses

I am following Buccaneer Bob Dark rum recipe and am super happy with the results.


I got myself a large 220L barrel of molasses



I also have a dunderpit going. At first I had a really nice brown bio layer floating on top and the whole thing smelled awesome. However, later on I got some mold on the top and ended up tossing everything and start from scratch (that's what you see in the picture).


The last picture is some final product sitting on oak for a couple of months now.
Can't wait to taste it

[MiddleOfTheWorld]

I see you like rum! Have a crack at a molasses wash mate, recycle the dunder a few times itll turn you off gin

The last picture is some final product sitting on oak for a couple of months now.
Can't wait to taste it

That looks delicious. toasted , charred or a mix of both ?