Squeeze or not to squeeze

[MSamu]

I just read that you should not squeeze the grain bag to express the liquid left inside. I just did an all grain batch and squeezed the hell out of it then I poured water through it and squeezed again until I had close to the max water, 5 gallons. Is this bad I squeezed the bags last brew but I didn't rinse like I did this time. The brew came out good. What is the theory behind not squeezing the bags? I want to improve so every little bit of info helps.

Thanks
Mike

 

[boydster]

It's an old wives tale. Squeeze yer sack. The theory was that by squeezing, you would extract tannins from the grains. It's since been pretty well shown that pH is a major player in tannin extraction and unless you really did something weird to your beer, your pH will be perfectly fine for squeezing the grain bag without fear of extracting tannins.

Here's a post from a thread that illustrates what I'm saying. The entire thread is a good read - it'll show you the evolution of what home brewers used to think just a few years ago through where we're at today - but the post I link to shows someone putting a good deal of pressure on the grains without getting any tannins. https://www.homebrewtalk.com/f39/squeezing-grain-bag-bad-175179/index5.html#post5446026

 

[MSamu]

Thanks for the link very informative.

 

[DaNewf]

I brew BIAB style in a 19litre kettle with the goal of getting 14-15litres into the fermenter.

When my mash is complete I let the bag drain over the brew pot until it pretty much stops. Then I dunk sparge in another pot. After I emtpy my "dunking" pot the first time I then put a colander over it and rinse the bag in it with hot water. Once the rinse is complete I take a large dinner plate and squat the hell out of the grain bag.

How hard do I press? My goal is to get the grain back to dry weight. It's impossible I know, but that's how hard I'm pushing. If its still dripping I keep pressing.

I repeat the rinse/squat procedure until I reach my boil volume (19 litre pot is almost completely full). So far it has worked and the beer doesn't have any astringent tastes (that I can detect anyway).

In my opinion you didn't do anything "wrong" in the brew where you squeezed without rinsing. I just like to "squeeze" every cents worth of goodness I can out of grain I paid good money for. It may actually be that I am doing something wrong because I've never bothered to figure out my efficiency and I don't care if my OG doesn't come in exactly according to the recipe.