Question about Taking Original Gravity

[Twisted Brick]

About to embark on my first AG venture: a 70/16/14 rye bourbon. I will be using US-04 yeast.

Last night I mashed up a 1/2 gallon batch of ground corn (11.8oz) and 2-row (4.2oz) in order to observe how a corn mash behaves, and to prepare a (batch of) yeast starters. After simmering at 190F for 45min I added the corn to a 1 gal cooler for 3 hours, then cooled and added the 2-row at 150F to convert overnight.

This afternoon I got an iodine 'all clear' indication from just the clear part of the mash so after squeezing, an OG reading read 1.072. The mash was very sweet.

Can this be right? The wort is much thicker than I ever achieved in AG brewing. Am I supposed to take a gravity reading on just the clear part before adding the last squeezin's that made the whole batch thick and syrupy?

I know ideal pitching gravity is 1.040, so I plan to dilute it before canning.

Any advice appreciated. Starter wort is on the stove now, ready for pasteurizing.

[still_stirrin]

...mashed up a 1/2 gallon batch of ground corn (11.8oz) and 2-row (4.2oz)...After simmering at 190F for 45min I added the corn to a 1 gal cooler for 3 hours, then cooled and added the 2-row at 150F to convert overnight. This afternoon I got...an OG reading read 1.072. The mash was very sweet. Can this be right?

Sure, it can.

The wort is much thicker than I ever achieved in AG brewing. Am I supposed to take a gravity reading on just the clear part before adding the last squeezin's that made the whole batch thick and syrupy?

When you say, “thicker”, do you mean “viscous”? Sugars in solution will be quite viscous...syrupy, if you will. It will thin...become less viscous as it’s heated.

To take the gravity, try to collect the “cleared” wort to the best of your ability. Some solids can affect the measurement, although more than likely, it will actually lower the true gravity measurement, not increase it.

But, when measuring the gravity of a wort, make sure you measure and correct for temperatures above (or below) your hydrometer’s calibration temperature (often 60*F). Temperature variation can amount to a significant mis-read on the gravity measurement.
ss

[HDNB]

what make you think 1.04 is ideal to pitch on?

if i could be so bold, i'd bet most pitch 1.065- 1.08

[zapata]

He's specifically making yeast starters, 1.040 is oft quoted as ideal for starters in the beer world. I agree.

Can your reading be right? Could be. Its pretty good, but not impossible good. Probably matters a bit what you mean by "1/2 gallon batch". I assume you mean you used 1/2 gallon water to start? That'd be 2 pounds per gallon grain bill, and 35 pppg. Which is pretty darn good, but how accurate were all measurements?

[Twisted Brick]

When you say, “thicker”, do you mean “viscous”?

Yes. I had originally thought to use the term viscous, but my UJ had other plans.

To take the gravity, try to collect the “cleared” wort to the best of your ability. Some solids can affect the measurement, although more than likely, it will actually lower the true gravity measurement, not increase it.

Thank you. As there were no definable chunks or solids, I led myself to believe the suspended smooth (syrupy) particulate was indeed rich, fermentable corn sugars, and would indeed contribute to a more accurate OG figure.

But, when measuring the gravity of a wort, make sure you measure and correct for temperatures above (or below) your hydrometer’s calibration temperature (often 60*F). Temperature variation can amount to a significant mis-read on the gravity measurement.

This is exactly where I got (more) cornfused. The alcohol temp correction calc uses ABV, not wash/mash readings. Is this not correct? Given that my hydrometer is the original one I started with 30years ago, I'm fairly confident it's calibrated at 60F, but that didn't help me. So I hedged my bet and reduced the gravity to 1.50.

what make you think 1.04 is ideal to pitch on? if i could be so bold, i'd bet most pitch 1.065- 1.08

Zapata's right, its what I read. The premise behind this is to not stress the yeast. But what frosts me is that numerous times I thought: what good is making a starter to familiarize the yeast at 1.040 when the mash ends up closer to 1.060-1.070? Thanks for the boldness, HDNB. I'll remember to go higher next time.

Which is pretty darn good, but how accurate were all measurements?

Good question, sir. Yes, I did use 1/2 gal, or 2:1 grain to water. I too question the validity of these measurements given the conditions: 1) I may have boiled a significant amount of water from the open corn mash kettle 2) my measuring devices are all 30yo 3) this is my first mash of any kind since electricity was invented

Thank you all, gentlemen, for your input. This is one helluva journey, and with your help I'm gonna get it licked.

[still_stirrin]

But, when measuring the gravity of a wort, make sure you measure and correct for temperatures above (or below) your hydrometer’s calibration temperature (often 60*F). Temperature variation can amount to a significant mis-read on the gravity measurement.

This is exactly where I got (more) cornfused. The alcohol temp correction calc uses ABV, not wash/mash readings. Is this not correct? Given that my hydrometer is the original one I started with 30years ago, I'm fairly confident it's calibrated at 60F, but that didn't help me. So I hedged my bet and reduced the gravity to 1.50.

Brewing hydrometers have correction curves as well....just like your Proof & Traille hydrometer. If you search a homebrew website, you’ll find the temperature correction calculator for your hydrometer.

Here’s a quick link: https://www.brewersfriend.com/hydrometer-temp/" onclick="window.open(this.href);return false;" rel="nofollow
ss

[HDNB]

i see. is "canning" the beer maker's term for making a starter?

FWIW, i have made starters with the mash often pushing 1.08 (or more compensating for measuring warm) for that matter my starters often are still 119" , since i start them before the mash cools to pitch at 115*...no off flavours i can detect.

i may be a bit past the recommended gravity here on the site. life on the edge

[Skipper1953]

I think "canning" is used by beer makers in the same way it is used by my wife when she is "canning" tomatoes. You put the wort in jars. You put the jars in a "canner" and process them. When you're finished, you have "canned" wort that you can use at a later date to make a starter.

[zapata]

Twisted, if you started with 1/2 gallon of water, then boiled the corn for a bit, I bet that is why your og is so high. It all makes sense if you boiled off some of the water, no worries, sounds like all went well.

[Blarney Stoned]

Here’s a quick link: https://www.brewersfriend.com/hydrometer-temp/ss" onclick="window.open(this.href);return false;" rel="nofollow

Thanks, ss

BS

[Twisted Brick]

Brewing hydrometers have correction curves as well....

Thanks, ss

[Twisted Brick]

what make you think 1.04 is ideal to pitch on?

if i could be so bold, i'd bet most pitch 1.065- 1.08

It felt a bit awkward to not remember the source or at least provide a clear explanation for my choice of 'ideal' pitching SG, so for clarification, here is my (late as it is) follow-up:

There are three main reasons to use a starter: increase colony size, acclimatize the yeast, and reduce lag time.

Yeast are really pretty sensitive creatures and proper handling should be practiced to insure good colony health. In the first few micro-seconds when yeast is introduced to a liquid environment they do not have the ability to control what passes through the cell walls. This is why proper rehydration in a sterile environment (with or without rehydration nutrients) is important. Simply introducing the yeast dry into the must or wort typically results in killing up to 50% of the colony.

Once rehydrated, it is best to acclimatize the yeast to it's new environment. Generally, a starter medium should consist of the must or wort diluted at least 50%. I have read some sources that recommend that the starter should have an SG of only 1.020-1.030. Also, when pitching the yeast into the starter temps need to be within 10 degrees. The idea is to provide as little shock as possible.

The amount of time for a starter is somewhat subjective and yeast dependent. The time frame should be at least long enough to get through the lag phase. This give the yeast sufficient time to adjust to the new environment and begin multiplying.

Big R

+1 rad

A starter is just that... a head start for your yeast. It is a micro-environment where the yeast get ready to be part of the bigger picture... your mash/wash. There are several reasons to make a starter. Yeast starters help accelerate fermentation. With a fast start to your fermentation bacteria are prevented from taking over reducing the chance of an infected batch. Starters allow yeast to multiply which helps achieve a lower final gravity and avoid stuck fermentations. Multiplication of yeast is helpful in larger batches as the higher number causes less stress to the yeast. Less stress means less off flavors. You don't always need a starter and that can be a matter of preference in some cases (I don't use starter when I make rum).

When making a starter the recommendation is to aim for a SG around 1.040. This provides enough sugar for cell proliferation without causing the colony to become stressed. Technically you will produce alcohol but not at a substantial quantity to notice(you usually use a small volume for starters and I decant a lot of the excess liquid off myself before pitching...YMMV). The presence of excess oxygen will keep the cells reproducing until the sugar is depleted.

The other benefit of making a yeast starter is decreased cost. I use a white labs liquid bourbon yeast. The damn vial costs $7 and is good for 5 gallons. I'm making up to 30 gallons so I need more... on top of that I want to save some of the yeast for another day. Keeping some of the yeast from the starter keeps it viable and healthy. Taking the yeast after it has run through the mash is also a possibility but if those yeast were stressed during their stay in your fermenter then you have "inherited" that stress for your next batch.

There are a number of other sources (especially in beer) that mirror these numbers, but these two are fairly concise summaries, and from (IMO) respectable 'stillers. Since some (ale) yeasts cross over from brewing to distilling, I felt the treatment of yeasts relevant in our application.

I now make a starter for all of my (15gal) ferments, and have gotten clean, consistent results throughout. Sure, simply hydrating yeast in plain water prior to pitching addresses the osmotic pressure dilemna, but with so many factors that contribute to final whisky flavor (good and bad), it's reassuring to know that following this approach can help reduce at least some of the variables.

[bitter]

I do about 1.042 for starters.. I usually use DME though to do a 1 to 1.5l starter and then step it up. Make sure you pick a yeast for your temp range.. and ideally one that goes as low as possible so less residual sugars. This will decrease the chance of scorching.

if you got 1g of liquid from your mash that indicates just over about 90% efficiency. That's on the high side but possible. I believe the boiling the corn and gelatinizing it gave you very high extraction of the starch.

I typically aim for 7.5 to 8% for the final beer to run. Things turn out nice there.

Edit. Forgot to add this. Temperature as mentioned very important. also let the wort settle clear. Clear wort will measure different than wort with solids in it

B

[Snickers902]

Just a quick thought to the issue of getting an SG reading in high solids mash. I've had to work around that issue too, I borrowed a buddies hops basket and was able to get a reading free of solids interference. The basket allowed liquids in put held the solids at bay. Was wondering if this would work for you?

[EricTheRed]

I take about 500ml of the wort and pour through a sieve to get 200ml of clearish liquid.
Take reading and pour all back in