I order extracts from NB and most of them come with a disposable mesh bag with specialty grains, the instructions specifying to take the grains out after the temperature reaches 170*F.

After pulling the mesh bag out, I have always squeezed it relentlessly to get every drip out of the mesh bag (often hurting myself from the heat in the process -- but I figured it was worth it).

Just 2 minutes ago, however, I was squeezing the mesh bag as normal when I noticed that the liquid seeping out of the mesh bag was altering the color of the (pre-)wort, and it struck me that this might not be a good idea. Thinking back on it, I've seen this before but it never bothered me.

Primary question: is it ok to squeeze the bag to remove every particle of liquid?

Secondary question: what accounts for the difference in color that I noted while squeezing the bag?


5 Answers 5


Yes, it is OK squeeze. In fact, you want as much extract as possible from the specialty malts.

It is a common myth that squeezing the grain bag is a bad idea due to "tannins being extracted" or similar. There is no reason for this to be true --- tannins are extracted from the grain (husk) only if the temperature during steeping/mashing is too high. And then not squeezing will not help. So squeeze away.

The observation that the color of the wort changes as you squeeze is simply due to the fact that you extract more of the darker-colored liquor from the specialty malt. This is good: if you do not squeeze, you need more specialty malt to achieve the same wort. You want as much extract as possible from the specialty malts.

Of course, steeping specialty malts is not an exact science.

  • Hm so in this particular instance, the color that I squeezed out from the mesh bag was actually lighter than the surrounding liquid. I cannot recall what happened on other times. Does this matter? I'll update this tonight with the name of the specialty grains. I'm also brewing again tonight and will update what I see with the color. May 21, 2014 at 20:15
  • Clear and make a lot of sense, but have you any experience with squeezing the bag or is it just your conclusion ? Myth or not, a very experienced brewer said me that some kind of pressure (how much ? I don't know) over the husks can extracts particles potentially resulting in off-flavors. In his experience just "rinsing" the husks and leaving the gravity to extract the remaining "juice" assure the best result in the end (without off-flavors risks).
    – Luciano
    May 23, 2014 at 19:54
  • 1
    @Luciano: I brewed a dozen batches with specialty grains/partial mash before I moved on to all grain. However, I am not an expert brewer either. I always squeeze the grain bag really hard, and the beer turns out delicious every time! I believe off-flavors from squeezing must in any case be negligible. See, e.g., John Palmer's "How To Brew" for an authorative guide.
    – Nemis L.
    May 25, 2014 at 20:33
  • 3
    Temperature DOES NOT effect Tannin extraction, otherwise decoction would not work. Tannin extraction is a function of pH. Again not an issue with squeezing the bag per se. But the temp statement is incorrect.
    – brewchez
    May 28, 2014 at 11:09
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    Typically yes. Which is why people will suggest acidifying the sparge water in some cases. All this requires knowledge of your mash pH and water profile/chemistry.
    – brewchez
    Jun 2, 2014 at 12:06

I always put the grain bag in a strainer and pour 2-4 quarts of 155-160f water slowly through the bag to remove anything additional from grains. This is the extract brewer's sparge equivalent. I've never read anywhere that squeezing was a good thing, but I have read from several reliable sources that it's a bad thing.

  • Just curious, do you have any text references with explanation as of why it is a bad thing to squeeze? I would really like to know, because I really cannot find an authorative text that says the opposite either, even if (my) common sense dictates it is ok and actually a good thing.
    – Nemis L.
    May 25, 2014 at 20:43
  • I stand corrected by John Palmer: "The procedure is identical to that for extract brewing. However, the specialty grains will be steeped in the pot before the extract is added. The 3 gallons of water in the boiling pot is heated until it reaches 160°F +/- 10°. Then the grain bag is immersed in the pot for 30 minutes. The grain bag may be dunked and swirled like a tea bag during this time to make sure that all of the grain is wetted. Agitation will help to improve the yield. Remove the grain bag from the pot, giving it a squeeze to drain the excess wort..." owl.li/xsUZY
    – Cortez
    May 31, 2014 at 7:45

Squeezing the bag is not bad, and will not result in off flavors. It also is NOT the ideal way to extract all the remaining sugars and color from the grains.

You are better off sparging the grain bag with hot water. You can set the bag in a colander, and pour hot water over it until the water runs mostly clear out of the bottom. This will more effectively flush the remaining desirable sugars and flavors from the grains to the wort.


One answer I was told was squeezing a grain bag (perhaps one with larger holes) may produce fine grain particulate matter, which would increase the quantity of protein matter and lead to boil overs. I have not read anywhere where this idea holds up. I lightly squeeze, but do not tightly grip.


I was always afraid to squeeze to release tannins.

But I did something I regret that I need to share: after getting the wort from BIB I decided to extract more sugars from the remaining grains not washing, but pouring hot water and closing the lid for an hour. Result? I got orange juice that would not disappear even after the secondary. Super turbidity.

Most likely this experiment released more proteins that were in suspension playing with the yeast. I decided to make it a non-filtered IPA but next time I will not repeat this excessive last running.

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