Help removing fruit solids

[Lighthouse]

I have a fruit beer in conditioning tank that won't drop clear enough to bottle. It was always going to be unfiltered, but the level of haze is excessive. It has a milky, colloidal look about it rather than a muddy yeast look. Under the scope, yeast density is a little over half a million per ml, perfect, but there is a lot of particulate matter of various sizes, the bulk of which is very fine, very much smaller than yeast. What to do. We have only light-duty filtration equipment here (a plate & frame and a 4x16" lenticular) and I'd need sub-micron media to retain this stuff. And there is so much of it...

Any ideas? Already fined with collagen; perhaps try another fining agent? Are there enzyme that can work on cellulose particles? Gack. I miss the days where I only brewed one beer...

[AnthonyB]

Did you pectinase the beer?

[Natrat]

What fruit?

[Lighthouse]

Didn't use pectinase. Have had an issue in the past with pectinase affecting foam stability in a pumpkin beer. The fruit is low in pectin and I don't think that's the issue. The problem is fine particulate matter that hasn't responded to fining. We cut the flaked wheat right back on the second brew without noticeable improvement, so I suspect that the fruit puree is the cause. I need a decent filter.

Puree was added to the whirlpool to give it a bit of pasteurization. It badly fowled the wort chiller with fibrous material which required a strip-down, wash and re-pack of the chiller. Never again...

I'll let you know what the fruit was once the beer is bottled and out there as people on this forum know who I am and therefore what the brewery is doing for summer.

[beerman_smitty]

Collagen is a positive fining agent that attracts negatively charged particles. You can try the opposite and bench trial bentonite with is used in wine to remove positively charged proteins involved in heat instability. Since the fruit was added during the whirlpool, it is possible that you induced a heat instability. Certain fruits, particularly certain varieties of grapes, will produce hazes when heated. Although, if the puree was a canned product, it wouldn't matter.

Generally though, when I use fruit purees, I will line a 5 gallon pail with a fine mesh bag and pour the puree into that, then add the bag to the other substrate, honey in my particular case. This allows for easy removal of the skin bits, seeds, etc from the other substrate will allowing for flavor, color, etc. Definitely would help keep your HX clean.

Since it is a fruit product I would contact Scott Labs and see which of their enzymes would work best for your scenario. http://www.scottlab.com/products-28.aspx
Probably KS or a similar product.

Fruit wine producers often use Sparkolloid as well. http://www.scottlab.com/product-204.aspx

Good luck.

[Lighthouse]

Thanks beerman_smitty

The fruit in question is actually rhubarb. Batch two worked a lot better as we had a very vigorous ferment and the bulk of the fruit pulp was ejected out of the FV. For batch three, I will send the purée to our local flavours/extracts guy and hopefully he can turn it into juice. And for next year, we will commission a fruit processor to make a juice or concentrate for us. I will contact Scott Labs to see if they have any suggestions.