Very high OGs - extract vs partial mash?

[Oginme]

Looking at your grains, you are using wheat malt which is enzymatic.  This is correct when adding the flaked grains, but also means you are doing a partial mash.  Any time you do a partial mash with enzymatic malts, you will get a higher extraction rate of sugars from the grains.  When you select the recipe type as 'extract', BeerSmith defaults to a lower extraction rate than you would get from the partial mash and that will cause your predicted OG to be lower than you will actually achieve.

 

[wepeeler]

Looking at your grains, you are using wheat malt which is enzymatic.  This is correct when adding the flaked grains, but also means you are doing a partial mash.  Any time you do a partial mash with enzymatic malts, you will get a higher extraction rate of sugars from the grains.  When you select the recipe type as 'extract', BeerSmith defaults to a lower extraction rate than you would get from the partial mash and that will cause your predicted OG to be lower than you will actually achieve.

Right, I get that. So my original post showed me getting a 1.072 instead of a 1.058. We figured it was from a partial mash, so I changed the settings to partial mash for my next batch. Target OG 1.064 and ended up getting 1.052. Switched same recipe to extract setting, and it changed target OG to 1.052, which is what I got. So the 1st time I did a partial mash and the 2nd time I didn't? Same ingredients, same technique. This is what is driving me nuts. How can there be a 20 point swing? 1.072-1.052....

Last night's brew was only 4oz of flaked wheat and 4oz of flaked oats. There couldn't be 6 points of fermentables in those 8oz, could there?

 

[Oginme]

"Same ingredients, same technique."

If you are brewing the same recipe and using the same technique, then I would suspect that this represents your process variability and/or measurement error.  How well can you measure your volumes going in and coming out?  Have your brew kettle and fermenter been measured and marked for volumes?  This is usually the biggest area of measurement error for most brewers.  I would not trust factory marked volumes as they are usually etched and added based upon a set template and do not take into account variations from piece to piece.

For your brew last night, 6 gravity points for how much volume?  Also, if you used only 4 oz of flaked wheat and 4 oz of flaked oats I would suspect that you may have measured some gravity, but it would be starch and not sugars.  The flaking process for grains brings the grains up to gelatinization temperatures and presses them to make the starches more accessible, but do NOT convert those starches to sugar.  In order to do this, you need a base malt to provide the enzymes needed to reduce the starches to sugars.

In the end, if you have converted malts (crystal, caramel, biscuit, brown, chocolate, black, roasted) then you can steep them and use extract settings.  If you have base malts or malts that need to be mashed (the description of each malt lists a "MUST MASH" as either 'true' or 'false'.  Malts marked as 'true' must be mashed to give you any fermentable sugars.) then use the partial mash settings.  If you find that the settings don't match your results, then you need to focus on tuning in the settings in your equipment profile to match your actual values.  Switching back and forth trying to explain your variability is not solving your problem, it is only causing you confusion and hiding the issues you need to address.

 

[GigaFemto]

You had a major change in process from the first recipes you posted to the recent set. In the first ones you had 0.25 - 0.50 gallons of trub loss, now you have zero. That will affect your efficiency and non-zero trub loss will cause BeerSmith to calculate the contribution from the extract incorrectly. So you had 3 different things going on that were affecting your OG calculations. If you have zero trub loss, then life is simpler. Choose between extract and partial mash the way Oginme said and you should be OK.

--GF

 

[wepeeler]

"Same ingredients, same technique."

If you are brewing the same recipe and using the same technique, then I would suspect that this represents your process variability and/or measurement error.  How well can you measure your volumes going in and coming out?  Have your brew kettle and fermenter been measured and marked for volumes?  This is usually the biggest area of measurement error for most brewers.  I would not trust factory marked volumes as they are usually etched and added based upon a set template and do not take into account variations from piece to piece.

For your brew last night, 6 gravity points for how much volume?  Also, if you used only 4 oz of flaked wheat and 4 oz of flaked oats I would suspect that you may have measured some gravity, but it would be starch and not sugars.  The flaking process for grains brings the grains up to gelatinization temperatures and presses them to make the starches more accessible, but do NOT convert those starches to sugar.  In order to do this, you need a base malt to provide the enzymes needed to reduce the starches to sugars.

In the end, if you have converted malts (crystal, caramel, biscuit, brown, chocolate, black, roasted) then you can steep them and use extract settings.  If you have base malts or malts that need to be mashed (the description of each malt lists a "MUST MASH" as either 'true' or 'false'.  Malts marked as 'true' must be mashed to give you any fermentable sugars.) then use the partial mash settings.  If you find that the settings don't match your results, then you need to focus on tuning in the settings in your equipment profile to match your actual values.  Switching back and forth trying to explain your variability is not solving your problem, it is only causing you confusion and hiding the issues you need to address.

I don't have my kettle marked for volume, but we measured the starting volume and boil volume with a caliper. We did simple math to determine boil off rate. We've been doing 5 gallon batches. I do need to etch volume markings into my kettle. That's next on the list.

As for the flaked oats and flaked wheat, I've been using white wheat malt in addition. I was under the impression it contains enzymes to convert the oats/wheat starch to fermentables. It just seems like sometimes I get a significant amount of fermentables from them and sometimes I don't. I thought that was the main culprit of my varying OGs. It's just frustrating to write a recipe with the extract setting and then have the numbers match the partial mash setting. And vice versa. Seems like sometimes I get fermentables from the "mash" and sometimes I don't.

You had a major change in process from the first recipes you posted to the recent set. In the first ones you had 0.25 - 0.50 gallons of trub loss, now you have zero. That will affect your efficiency and non-zero trub loss will cause BeerSmith to calculate the contribution from the extract incorrectly. So you had 3 different things going on that were affecting your OG calculations. If you have zero trub loss, then life is simpler. Choose between extract and partial mash the way Oginme said and you should be OK.

--GF

Right. I've adjusted the trub loss to zero across the board now. I was always dumping everything into the fermenter and didn't realize the trub loss affected the gravity so much.

I just need to brew a few more times and tweak the settings accordingly. I'm getting closer to my numbers, so that's a good thing.