partial mash question

How are you computing the expected OG which you are not hitting?
How are you crushing your grains and how fine is the crush?

 

To build on what @VikeMan said, are you mashing at a (somewhat) consistent temperature? Are you "mashing out" by raising the temperature to 170 or so?

A recipe would also be helpful to see for some additional diagnosis.

 

From what I see, I would have the strike water at max 155 and the sparge water at 170 or so.

Are you mashing in a small cooler? How "not very close" are you getting to the OG?

 

After watching the video-
Stir inside the bag.
Mash for 60 minutes
Stir inside the bag when mashing

Check out BIAB- even on a smaller scale this may be a much better option for you. http://www.love2brew.com/Articles.asp?ID=387

 

What was the temperature of your mash after it settled?

 

There is no standard strike water temperature. It depends on the mash temperature you want, the amount of water, the amount of grains, and the thermal properties of the container you are mashing in. If you are above or below the ideal range, that could affect your mash efficiency.

Mash pH can also affect mash efficiency, but I'd make sure the mash temps are good before I'd worry too much about that.

 

1.060 to 1.051 is not too bad. If you are consistent, its better than high efficiency.

I usually stir every 15 minutes or so to make sure the temperature is consistent throughout the grains. 30-45 minutes seems short to me, but I am not 100% on the science. I would take the extra time to ensure full conversion. I usually try to be a little thin and add some warm water if needed throughout the mash to maintain consistency. Keep an eye on the mash temperature, but don't go too crazy (as in checking every 5 minutes).

 

But that gravity difference is for his whole wort, including extracts. And extracts should be dead on. Which means (assuming the recipe assumed a reasonable efficiency) his mini-mash efficiency is way off. There's definitely a problem here, either in measurement or process.

 

When I first started partial mashing I used a method similar to the one in the video you posted. Here is a suggestion, rather than tying off the grain bag, leave it open when you first lower it into the strike water, this allows you to stir the grain inside the bag, rather than dunking and prodding the bag with your spoon hoping to adequately soak your grain. Once you have wetted the grains to your liking you can then tie off the bag. In addition to the advice from previous posters, this may help you gain greater efficiency.

 

My advice, don't use a grain bag. Use a 5 gal nylon paint strainer instead. I just wrap the elastic end around my kettle used for partial mashing. The grains don't clump then and it makes for easy mixing and stirring. When you're done mashing, you can still simply pull the bag and let drain.

 

That's a great idea. Or, the OP could skip the bag entirely. Buy a ball valve, and some braided stainless water supply line to use as a manifold. OP check out Denny Conn's or Don Osborne's websites for inspiration on building a mash tun. Simple, cheap, and effective.

 

I'm thinking your problem probably has to do with your mashing temperature. The temperature of your mash is 100x more important than the temp of your strike water. If your mash is outside the temp range of about 145-155, your efficiency will suffer and you may get no conversion or minimal conversion. If after adding strike water your temp is above that range, add cool water to lower it. If it is below that range, add more hot water. If its perfect, remember the amount and temp of the strike water for next time.

Start measuring the temp of your mash with a thermometer. Do this at various stages during the mash because you may experience a drop in temp that must be corrected over the course of the 30-60 minutes.