No Conversion of starch to sugar

Goose06

I took biermunchers Centennial Blonde recipe and divided it by 5 to get a 1.5 gallon batch from his original 5.5 batch. I mashed at 155 for one hour in one gallon of water. I then rinsed the grains with a half a gallon of water. I boiled for 60 minutes and did my hop additions as instructed. I cooled the wort to 70 degrees and took a hydrometer reading. The reading was 1.010. Thinking this had to be a mistake I did a test calibration with my hydrometer and it was accurate. All the grains are from More Beer and milled. It appears I was left with almost exactly a gallon of wort so I don’t think the water addition lowered it. This is my third brew and I’m having trouble figuring out what the issue here was.

VikeMan

Is your hydrometer multi-scale (most are)? If so, are you sure you weren't looking at the Brix scale? 10 Brix = 1.040.

Goose06

Yes 100% sure I’m on the right scale. The best I can think currently is maybe my scale was wrong when I weighed the grains.

IslandLizard

What grain did you order, and are you sure that's what they sent you?
How fine (or coarse) was the milling? Were there many whole, uncrushed kernels left in there?
You sure there's a base malt included?

Goose06

I have 2 row malt, carapils malt, caramel malt, and Vienna malt. I can tell it’s milled, it has a lot of what look to be whole kernels but when I place them in my hand they all are cracked but it doesn’t appear to be as fine as I’ve seen in some YouTube Videos ect.

IslandLizard

Check your scale with a known weight, such as an unopened bag of sugar, or flour, or such.
Or use a container filling with a measured amount of water.
How much grain were you aiming at using?
IIRC, a quart (take-out soup) container holds around 1.5 pounds of unmilled grain.

Goose06

Just checked my scale with a pre measured bag of priming sugar. It read 5.1 ounces when the bag is labeled as 5oz. I converted the 5.5 gallon recipe into a 1.5 gallon recipe and the total weight of the grains was around 2 pounds.

IslandLizard

You mean when you squeeze those whole looking kernels between your thumb and index finger they pulverize? If so, that's good, they're indeed crushed. Now the pieces may still be relatively large, but most should be no larger than 3/32".
Did you put the grains in a mesh bag when mashing? Then stir well? so the whole content gets thoroughly hydrated. Did you check the temp after stirring and during or after the mash?
A small volume can lose heat quickly, dropping below 140F, where conversion activity starts to cease.

Goose06

I did all of those things but I just tested the calibration of my thermometer compared to my digital thermometer and it is off between 5-8 degrees. If I held the mash temp between 150-155 per that thermometer. It was at 150 the majority of the mash so realistically it was probably between 142-145. Could that have caused the issue?

BrewnWKopperKat

What did you use for source water? any water adjustments?
FWIW, temperature is likely to be a primary cause, but 'bad' water could be a contributing factor.

Goose06

I use the gallon jugs of spring water from the grocery store. I haven’t had an issue with it in the past. No adjustments.

IslandLizard

One of the best ways to keep a (small) mash pot warm is putting it inside a warmed up but turned off oven.
Wrapping insulation (thick blanket, sleeping bag, etc.) around the pot (including the bottom and lid), helps keeping the mash temps too.
At 142-145F conversion will take place but it takes much longer. Alpha Amylase (chopping starch chains into smaller pieces) becomes inactive below 140F.

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IslandLizard

[Quoting myself]
The good news is, inside the narrow "Brewers Window," between 146-158F, the mash proceeds rather quickly as soon as the grist gets hydrated. It could be 70-80% done in 10-15 minutes, especially if the grist is finely milled, and the mash is not overly thick or thin. 1.25-1.75 quarts of water per pound of grain is a good starting thickness.

Goose06

Great advice thank you! I would think this is probably the issue since I did get some conversion with a reading of 1.01. Best part about the small batch is I have lost much and I have enough to make it again today. I’ll let you know how the second round goes.

IslandLizard

Ah, good!
Measure the gravity at the end of the mash. It should be around what you'd expect, and quite a bit higher than the projected OG, as you haven't sparged yet.
The other thing one could do to prove the mash was successful and completed is performing a residual starch test with half a teaspoon of wet grist on a white saucer (or plate) and a drop of Iodine. If the grist (the pieces of grain) turns blue it still contains starch, and the mash should be continued. There are precise instructions around on how to do that test.
You can get a small 1 oz bottle of Iodine tincture at your local pharmacy for $1-2 or so. Local homebrew stores may also have them.
It's the same Iodine one would use for disinfecting small scrapes and cuts, so it's dual purpose.  

Mike-B1190

Do you normally take pre-boil gravity readings? If not, it might be good to start. Then you would be able to notice something like an extremely low gravity before you start the boil. Then you could try to correct it with malt extract, sugar, or maybe even attempt to reintroduce the grain to the wort and try to continue mashing. I have no idea if the latter of those would work, it's just a thought.
Refractometers are great for checking gravity during and after the mash, in my opinion.
Also, you may find helpful an equation I use to determine what my preboil gravity should be. If I find that my preboil is lower than what it should be, I can add malt extract to hit the OG I'm targeting.
Pre-boil Gravity = post boil gravity * post boil volume /pre boil volume
You use whole numbers for specific gravity in the equation, 1.050 would be 50, for example.

BrewnWKopperKat

FWIW, I put the full recipe into Brewers Friend's mash/water calculator (link). Assuming no data entry errors (and modeling the water as just RO water), the mash pH appears to be at the very high end of the range (or maybe just beyond).
For pale beers with no mineral water, a small amount of acid or acidulated malt to bring the pH down towards the middle of the range. Something to keep in mind if efficiency continues to be lower than 75-ish%.

hotbeer

I recommend you do the iodine test for starch conversion too on your next attempt.
And as soon as you get mashed in, do a test right away so you can see what it looks like when you have a high ratio of unconverted starches.
Then the later test that shows or should show most everything completely converted won't be as confusing.
However I still wonder if you had everything scaled correctly and possibly just diluted your wort too much.

grampamark

This seems unlikely, given that the caramel and Carapils would be a small percentage of your recipe, but by way of eliminating one more probable cause for your low OG I have to ask.
Were the grains you weighed for this batch weighed separately or had the grist for the larger batch size already been combined and you weighed out 20% of that combination? It would take a pretty significant amount of stratification of the mixed grains for this to be the cause, but I suppose stranger things have happened.  

Goose06

they are in individual bags and I weighed them separately.

Goose06

I have figured out the issue, I was ready the scale i have wrong. I was supposed to be using 1.5LBS of 2 row and was using 15 ounces. That translated Into all of the grain measurements. Of course I couldn’t get any gravity, nothing in there to convert to sugar!

marc1

Another point to consider:
What size was the grain bag relative to the mash tun?
If you are mashing and not steeping, you want the bag to be as big as the whole tun. You do not want much water outside of the bag, which will reduce efficiency. The grain should be free floating and loose in the mash, not tied up tight in a ball.

IslandLizard

That answers some of the low gravity, but...
Your 2-row alone was supposed to be 1.5lbs = 24 oz
You only used 15 oz
1 pound of 2-row should yield around 32 points in 1 gallon (32 ppg) at 85% mash/lauter efficiency.
If the mash went well with full conversion, that still should have given you 15/24 * 32 points/gal = 20 points in 1 gallon, or a gravity of 1.020, after the boil. Not 1.010.
And it should be a bit higher than 1.020, since there were other grains in the mash too, also contributing gravity.
So your mash process definitely needs some close attention.