Difference between sparging and mashing?

I'm looking to make an oatmeal stout. If I understand correctly oats need to be mashed to extract fermentables from them and avoid simply contributing starch to the brew. I have only done extract with specialty grains before so I have been researching the partial mash process. I stumbled upon this video which seemed to give a relatively straightforward explanation:

My question is: Why not simply throw all the specialty grains, oats, and base malt in my nylon steeping bag and do the entire process in the brewpot itself, while maintaining a constant temperature on my stove. And then just pour sparging water over the bag while suspending it over the brewpot. I'm sure this is a noob question but I'm just looking for some clarification on how the process differs from steeping in the brewpot. Does the process shown in this video simply serve to give closer control over temperature regulation and better extraction from sparging? Thanks all.

You've got the talking points of the "brew in a bag" aka BIAB technique. Lots if threads about that in here.

>>My question is: Why not simply throw all the specialty grains, oats, and base malt in my nylon steeping bag and do the entire process in the brewpot itself, while maintaining a constant temperature on my stove. And then just pour sparging water over the bag while suspending it over the brewpot.

Many people, including me, do this.

Mash all the grains at say 150F for an hour, pull out the bag, let it drain, SCOOB*, and then boil. Makse for an easy and shorter drew day.

(SCOOB = Squeeze the Crap Out Of the Bag)


>> I'm sure this is a noob question but I'm just looking for some clarification on how the process differs from steeping in the brewpot.

Steeping doesn't result in mashing (i.e. no conversion of starch to sugar). Its solely to extract flavor, and maybe some sugar from the grains.
Steeping is done at a higher temperature, like 165.

>>Does the process shown in this video simply serve to give closer control over temperature regulation and better extraction from sparging?

Its a different process.

When you say Sparging, do you mean mashing out (at 168)?
The purpose of Mashing out is to denature the enzymes (make them stop working) to lock in the wort sugar profile.
It also is easier to extract sugar from the grains at a higher temperature

The only difference between brew in a bag and steeping is that you include base malt for BIAB. Otherwise it's exactly the same process.

The grains you can steep are grains whose sugars are already fully converted, so no mashing is needed. Base malt needs time for enzymes to convert its sugars.

So, mashing and steeping are exactly the same procedure. The only difference is what's in the bag and how long it takes. If you can do extract with steeping grains, you can do all-grain BIAB.

>>So, mashing and steeping are exactly the same procedure.

Not really. They are done at different temperatures, and for different lengths of time.
Water chemistry is more important in mashing because it can affect the enzymes.

What they have in common is: - "put the grain in a bag"

If you are using quick oats - yes.

Steel-cut oats need cooking.