Prioritizing Equipment purchases

So for Christmas I got some gift cards and extra cash and am trying to prioritize what equipment I want to buy. I brew all grain and am pretty set as far as equipment goes. I am looking at more precise control over my process. I am currently thinking about two items:

1) Microscope or

2) DO meter

I currently have control over fermentation temperatures, a grain mill, a thermapen, a pH meter, refractometer, pretty precise hydrometers, a decent gram scale and I aerate with an oxygen tank that has a flow meter. I am leaning toward the Microscope for right now so that I can precisely control my pitching rate, I grow extra yeast each time and keep them in the refrigerator. Though the DO meter would be nice to know just how much oxygen I have in my wort. Anyone have opinions or can think of any other equipment that I might not be thinking of, but want first to gain better control over my measurables when brewing?

I went to a seminar on microbiology one of our LHBS put on...she is a microbiologist...my conclusion...let wyeast, white labs, etc look under the microscope and just follow their directions

But if you understand it all...go for the microscope....I've to look at my notes from that presentation..there definitely is a minimum size you will need for yeast cells...plus all the other equipment for sterilization

brewmeister13 said:

So for Christmas I got some gift cards and extra cash and am trying to prioritize what equipment I want to buy. I brew all grain and am pretty set as far as equipment goes. I am looking at more precise control over my process. I am currently thinking about two items:

1) Microscope or

2) DO meter

I currently have control over fermentation temperatures, a grain mill, a thermapen, a pH meter, refractometer, pretty precise hydrometers, a decent gram scale and I aerate with an oxygen tank that has a flow meter. I am leaning toward the Microscope for right now so that I can precisely control my pitching rate, I grow extra yeast each time and keep them in the refrigerator. Though the DO meter would be nice to know just how much oxygen I have in my wort. Anyone have opinions or can think of any other equipment that I might not be thinking of, but want first to gain better control over my measurables when brewing?

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If it were me, I'd go with the microscope. Being able to do cell counts would be cool, especially if you're already plating, isolating and slanting your yeast. Then you could really dial in your pitch rate even if you weren't using a WL/Wyeast product.

Far be it from me to dissuade you from doing something you enjoy, but both items seem low-priority to me with regards to critical control points.

If you pitch a fresh, saturated starter, you're doing as good as you can: getting a viable cell count is not going to help, even if it's accurate (which is not trivial to achieve).

I have similar qualms with a DO meter. Correct me if I'm wrong, but I thought that the 02 saturation point was pretty constant and easily achieved. What would you gain by measuring it?

All that said, microscopes are fun. I'd get that.

corax said:

Far be it from me to dissuade you from doing something you enjoy, but both items seem low-priority to me with regards to critical control points.

If you pitch a fresh, saturated starter, you're doing as good as you can: getting a viable cell count is not going to help, even if it's accurate (which is not trivial to achieve).

I have similar qualms with a DO meter. Correct me if I'm wrong, but I thought that the 02 saturation point was pretty constant and easily achieved. What would you gain by measuring it?

All that said, microscopes are fun. I'd get that.

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What would you consider higher priority? One of the reasons I posted this was to see if there was something that I may be missing.

My thought on the microscope was that once I am 3-4 generations into a yeast it is really a guessing game as to how many cells I am beginning with for my starter. Sure I may have saved approx. 100 billion cells, but how many were viable? Was I off in my estimation to start with? Eventually I would like to start to apply selective pressure on different yeast to create something of my very own (may not ever happen, but it's a goal I have).

To me the DO meter would be nice, but once I got a certain number of data points would be less important. As I understand it the saturation level of pure O2 in wort is close to 43 ppm, which is way over the usual 8-12ppm that most yeast find optimal.

Conical fermentor.

brewmeister13 said:

What would you consider higher priority? One of the reasons I posted this was to see if there was something that I may be missing.

My thought on the microscope was that once I am 3-4 generations into a yeast it is really a guessing game as to how many cells I am beginning with for my starter. Sure I may have saved approx. 100 billion cells, but how many were viable? Was I off in my estimation to start with? Eventually I would like to start to apply selective pressure on different yeast to create something of my very own (may not ever happen, but it's a goal I have).

To me the DO meter would be nice, but once I got a certain number of data points would be less important. As I understand it the saturation level of pure O2 in wort is close to 43 ppm, which is way over the usual 8-12ppm that most yeast find optimal.

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I agree that these seem "low priority" for the reasons pointed out by corax..... but, hey, everyone has different things they enjoy about the hobby. And, my recent idea of "high priority" was the beer engine I bought myself for xmas..... which I am sure most would consider "low" priority. So, what do I know?

Other thoughts - new kegs, some sort of bar/serving upgrade, better fermentation chamber, new fermenter, books, upgrade your brewing area, better starter equipment (bigger/better flask, stirplate, etc).... A beer engine .....just some thoughts/possibilities.

brewmeister13 said:

What would you consider higher priority? One of the reasons I posted this was to see if there was something that I may be missing.

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It looks to me like you've got the fermentation process pretty well nailed. How are you set for mashing, chilling, etc? If you're happy with the control points there, I'd just go for equipment upgrades.

My thought on the microscope was that once I am 3-4 generations into a yeast it is really a guessing game as to how many cells I am beginning with for my starter. Sure I may have saved approx. 100 billion cells, but how many were viable? Was I off in my estimation to start with?

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The beginning of a starter is much less important than the end -- and for the end, a starter of a given gravity will yield a reliable cell density, regardless of how many cells you started with.

Also, how are you planning to measure viable cells -- hemocytometer and vital staining? Certainly doable, and if that's what you're in to great, but for me that would be an unnecessary complication.

Eventually I would like to start to apply selective pressure on different yeast to create something of my very own (may not ever happen, but it's a goal I have).

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That sounds cool, and a microscope would certainly come in handy -- if for no other reason than to confirm that you've selected for yeast!

To me the DO meter would be nice, but once I got a certain number of data points would be less important. As I understand it the saturation level of pure O2 in wort is close to 43 ppm, which is way over the usual 8-12ppm that most yeast find optimal.

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Ah, then the DO meter does make sense as a control point. Still doesn't sound as fun as a microscope, though!

I am assuming you have a precise HERMS or RIMS system, I think they control over temps is more impactful than yeast or oxygen precision.

OTOH, a microscope is very cool and someday...

Microscope could also measure infection levels. Might also have other uses as a tool around the house.

DO meter might not be accurate, depending on how much you spend. It could be useful, but not to measure how much is "in your wort", but more so for finished beer.

Double post

corax said:

It looks to me like you've got the fermentation process pretty well nailed. How are you set for mashing, chilling, etc? If you're happy with the control points there, I'd just go for equipment upgrades.

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Cyclman said:

I am assuming you have a precise HERMS or RIMS system, I think they control over temps is more impactful than yeast or oxygen precision.

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I direct fire, recirculate my MT and am pretty good at keeping it within about a degree most of the time, but definitely do want to automate in the future. Chilling is set, I recirculate ice water through a CFC.

corax said:

The beginning of a starter is much less important than the end -- and for the end, a starter of a given gravity will yield a reliable cell density, regardless of how many cells you started with.

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Are you sure this is true? If so can you point me in the direction of a link so I can better understand this? From what I understood, and I am basing this off of playing with yeast calculators, the ending cell count changes when the beginning count is raised or lowered. However, the amount of DME used is the critical factor in the size of the growth. A 2 liter 1.036 starter and a 1.8L, 1.040 starter will yield the same estimated ending cell count, as they both use 7.2 oz DME.

Thanks for all of the input. You guys have definitely given me more to think about, and research, before I make any decisions. If anyone else has a take on this I'll probably not make any big purchases for a little while.

The beginning of a starter is much less important than the end -- and for the end, a starter of a given gravity will yield a reliable cell density, regardless of how many cells you started with.

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brewmeister13 said:

Are you sure this is true? If so can you point me in the direction of a link so I can better understand this? From what I understood, and I am basing this off of playing with yeast calculators, the ending cell count changes when the beginning count is raised or lowered. However, the amount of DME used is the critical factor in the size of the growth. A 2 liter 1.036 starter and a 1.8L, 1.040 starter will yield the same estimated ending cell count, as they both use 7.2 oz DME.

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It's just a matter of population growth vs. resource consumption. A given volume at a given sugar concentration can only support so many cells. If you start well below that limiting number (say 1/10th or less) the cells will quickly multiply until they come close to the limit (exponential growth phase), then slow down and approach the limit asymptotically (late log phase). I did enough growth curves back in the day to know that if the yeast calculators aren't telling you that, then the yeast calculators are wrong.

Now, if you start close to or above the limiting number, all bets are off. You would likely get less than one complete population doubling, but you might end up with more viable cells than the theoretical limit. But I would want to use a starter that had gone through a healthy exponential growth phase, and such a starter will end up very close to its theoretical limit -- much closer than the margin of error you'd get by counting cells with a microscope and hemocytometer.

corax said:

It's just a matter of population growth vs. resource consumption. A given volume at a given sugar concentration can only support so many cells. If you start well below that limiting number (say 1/10th or less) the cells will quickly multiply until they come close to the limit (exponential growth phase), then slow down and approach the limit asymptotically (late log phase). I did enough growth curves back in the day to know that if the yeast calculators aren't telling you that, then the yeast calculators are wrong.

Now, if you start close to or above the limiting number, all bets are off. You would likely get less than one complete population doubling, but you might end up with more viable cells than the theoretical limit. But I would want to use a starter that had gone through a healthy exponential growth phase, and such a starter will end up very close to its theoretical limit -- much closer than the margin of error you'd get by counting cells with a microscope and hemocytometer.

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Thank you for the great information Corax. I've been using Brewer's Friend yeast calculator since it uses Kai's growth model for agitated starters and doesn't just provide a scaled assumption of non agitated testing. How would I estimate the theoretical limit that a given wort would support? I'm also under the impression that a given population can only reach a certain size regardless of starter size (ie. you there is a limit to the effectiveness of added volume; a 10L starter will only provide a small amount more yeast than a 2L starter). I believe I picked this up from the book "Yeast: The Practical Guide to Beer Fermentation". Sorry this has gotten so far , but I really appreciate all of the information.

Also, do you know off hand what the error margin is for counting with a hemocytometer? If it is large, how do the pros get consistent pitching rates?