First Yeast Starter: Gravity Increase

[UKSkydiver]

I had saved something yeast from a couple of months ago. I know it’s ‘old’ but I wanted to at least try using it I need a starter having recently cobbled together a stir plate.

To be honest, It didn’t matter if it didn’t work and i didn’t really expect it to work anyway. I have a packet of S-04 in case.

Details are this:

Soaked the spent grain in a couple of litres of water (does that make it second runnings?) and after boiling and cooling got about 1.2 litres of 1.024 wort. I know it’s low, but again, I was just fannying around seeing what I could do. No expectations.

Yeast (S-04) has been in the fridge since mid April, nicely separated out in a standard 400g jam jar. There was maybe 3-4mm slurry on the bottom. This weighed out to about 10ml

So I stick on the stir plate about 9pm. Not really sure what I'm looking for. I suspect no bubbling or krausen as the stir plate is doing its thing,

I decided to measure the gravity to see if it’s done anything, not really expecting it to have worked, yet to my surprise it’s gone up to 1.052!

Hydrometer is calibrated and temps were all room temp, 19-22 degrees.

Can anyone explain my findings? Have I likely done something wrong?

Cheers

 

[cushyno]

Are you measuring gravity in a trial jar or in your starter FV? Just a thought, is the hydrometer resting on the bottom?

 

[strange-steve]

Suspended solids such as yeast in the sample will affect the SG reading, as will CO2 being produced during fermentation, but I don't think I'd expect such a big difference.

 

[UKSkydiver]

Are you measuring gravity in a trial jar or in your starter FV? Just a thought, is the hydrometer resting on the bottom?

Trial jar. I made sure it was bobbing up and down.

 

[UKSkydiver]

Suspended solids such as yeast in the sample will affect the SG reading, as will CO2 being produced during fermentation, but I don't think I'd expect such a big difference.

It's entirely possible I'm being a doughnut, this starter lark, it's just not sinking in . . . . yet.

 

[cushyno]

Why would the gravity have increased? One of your measurements was most likely incorrect. Starter wouldn't have increased in gravity on its own.

Steve hints at why the reading may be incorrect. Temperature, suspended particles, bubbles of co2, poorly mixed wort can all skew hydrometer readings.

I don't like doubting your readings, but can't think of any other reason.

 

[UKSkydiver]

Why would the gravity have increased? One of your measurements was most likely incorrect. Starter wouldn't have increased in gravity on its own.

Steve hints at why the reading may be incorrect. Temperature, suspended particles, bubbles of co2, poorly mixed wort can all skew hydrometer readings.

I don't like doubting your readings, but can't think of any other reason.

I know, its bizarre. I thought maybe I mixed up the readings or something. The starter wort was definitely from the second runnings. It definitely wasnt as high as 1.050. I kinda expected it would be lower down to there being less sugar.

Ah well.

The real beer has a packet of S-04 in there now. The stir plate is still going. I will take another reading for shits and giggles and then cold crash and see what we have.

Thanks for taking the time to read and answer