How Long Can You Keep Oysters In A Cooler

Ah, the age-old question: how long does something perishable last? We have all asked that at some point in our lives, particularly in front of our fridge. Sometimes, it'south easy to figure out: a weird smell, visible mold – it's probably time to throw it out. Merely what about perishable foods with less obvious signs, similar oysters without "Best By" dates?

We have been conditioned to rely on dates to help united states of america determine if something is all the same fresh or safe to eat, but what does "fresh" really mean for oysters? Have we assessed quality without a date bias? Our industry has become so focused on harvest dates and marketing that the oyster's bodily freshness is being disregarded.

From a food prophylactic perspective, oysters stored at proper temperatures can be condom to swallow for months. Oysters were historically stored in pits or cellars during winter and consumed during the winter months. "Pitting" or overwintering oysters in coolers and cellars is still a popular technique for growers to keep oysters safety from winter sea water ice.

From a freshness perspective, nosotros at Pangea Shellfish define oyster freshness as the post-obit:

A fresh oyster is live, has ample liquor, and maintains its olfactory property and flavor from harvest.‍

A fresh oyster is alive, has ample liquor, and maintains its aroma and flavor from harvest. -

Based on that definition, there are some signs when an oyster has gone bad:

The oyster is gaping open, which ways it is weak or dead.
The oyster is dry, which means it is weak, injured or dying.
The oyster smells or tastes different from harvest.

We take more often than not found oysters to maintain our definition of "freshness" for up to 14 days. Our observations, though, have been anecdotal, and we didn't have concrete proof. And so, for the month of May, we decided to put our assumptions to the exam past shucking one oyster per day and tracking the changes over time.

A Month-Long Freshness Exam

The Sample

For this test, we used a 100-count bag of Salten Stone Oysters from our Blish Point Oyster Subcontract in Barnstable, MA. We chose this oyster because we knew its seed to market process intimately. If something occurred during the examination, we could potentially trace the event dorsum to the farm.

Procedure

We randomly selected 1 of 14 bags from Lot C-748. The lot was harvested on Sabbatum, Apr 27, picked up past our company truck, and received at our Boston facility at 4:40PM the aforementioned mean solar day. Nosotros stored the bag of oysters in a crate, on a shelf, and in our libation for the entire examination period. The cooler temperature averaged 41° F. The oysters received no special treatment. No special treatment, no water ice or special storage, and no wet storage.

We evaluated i oyster per mean solar day. Before Bekah and I shucked each oyster, nosotros recorded the oyster's size in inches and weight in grams. Once open up, we recorded its temp, captured a photo, and noted its liquor content and flavour. On the last twenty-four hours of the test, May 31, we shucked all the remaining oysters to meet how they held up.

Data & Results

Starting Bag Weight: 13.96 LB
Catastrophe Bag Weight: 13.xix LB
Weight Change: -0.77 LB

Bag Yield: 96% (4 oysters expressionless or dry)
Size range: 3.0" - 4.0"
Average size: iii.six"

Effigy one: The following shows the weight of each oyster evaluated per day during the examination.

one oyster weight was recorded each work day in May. 79 oyster weights were recorded on may 31.

Figure 2: The following shows the distribution of oyster weights shucked on May 31 (34 days post-harvest). The average weight of these oysters were 56.1 grams.

Most of the oyster weights ranged between 48 to 64 grams. Mean: 56.1 grams; Median: 55.2 grams; mode: 56.4 grams.

Figure 3: The post-obit photos and notes were captured to assess meat, liquor, and flavor.

Word of Results

Change in Overall Pocketbook Weight

At the start of the test, the bag weighed xiii.96 lb, and over the 34-day menses, it lost 0.77 lb (349 grand). If we average the weight loss across the bag, each oyster lost about 0.0077 lb (~three.5 1000), about the weight of ii playing cards. We expected this weight loss and information technology'due south within reason. Over time, wet from the outer shells will evaporate and some oysters will weaken, losing some of its liquor in the procedure.

Change in Individual Oyster Weights

Nosotros hypothesized that the private weight per oyster would decrease over fourth dimension due to the expected moisture and liquor loss. What nosotros found, yet, was there was no directly correlation between fourth dimension transpired and weight. In fact, oysters evaluated on May 31 (34 days mail-harvest) ranged upwards to lxxx.9 grams, heavier than all oysters evaluated prior. Liquor was also visible in most of the oysters on the last day (see Effigy 3).

This doesn't mean that the oysters gained weight later harvest (that'd be highly improbable). Instead, this called out a flaw in our testing method. We were just as likely to draw 5 of the largest oysters or smallest oysters from the bag each week. Doing a more extensive test or having an oyster "control grouping" would make this more than bulletproof. Only hey, we're oyster people, non scientists. One thing we can say is that the oysters we selected each day were of average weight compared to everything else in the bag (encounter Figure 1).

Change in Smell and Flavor

The oysters evaluated towards the beginning of our exam easily met our definition of fresh: ample liquor, bang-up meat fill, and flavor on indicate. The oysters connected to pass our standards for a few weeks with a couple exceptions (May 8 & 10). There were no significant changes until we reached May 17, 20 days postal service-harvest. From that point on, the odour and flavour started to plough. A couple of dead oysters started to make the bag stink. Oysters still had full meats and liquor, but they no longer tasted clean or pleasant. The funky lingering finish clearly was not representative of its merroir anymore.

Conclusions & Considerations

And so what did we conclude or prove from this test?

1. Oysters are safe to eat even 30 days after its harvest appointment *if it has been handled and stored properly.

Here is a photograph of me eating one of the oysters on May 31, 34 days post-harvest. Happy to report I did not become sick and am live and well to write this! (I also ate them during week 5 to assess flavor.) The caveat nearly handling and storage is super important to mention, though. The oysters were safe to eat because they were properly handled and stored at temp. This is a must to ensure safe consumption regardless of its harvest date. Mishandling is one of the greatest risks for foodborne illnesses acquired by oysters, and then please practise your part.

2. An oyster tin maintain its "freshness" or quality upwardly to 14 days after harvest.**

From our test, oyster quality started to refuse twenty+ days after harvest. Nosotros by and large tell customers oysters stay fresh upwards to xiv days, just our results showed the menses of freshness may actually exist longer. We similar to err on the side of circumspection, and so 14 days from harvest is probably a practiced dominion of pollex to follow.

**This is a general conclusion and may not apply to all oysters. Nosotros recognize that dissimilar species of oysters have different shelf lives. Atlantic oysters (virginica) tend to keep better than Pacific oysters (gigas). Performing this test with Pacific oysters could take yielded a shorter freshness window. Nosotros used a farmed oyster versus a wild oyster. We used a Massachusetts oyster that feeds longer than a Canadian oyster. We acknowledge these differences in oyster characteristics can impact the outcome. This was also simply one test done on a minor scale. Perhaps nosotros will echo this again to compare our results, and maybe on some other variety!

3. Freshness is not adamant by dates, weights, or visual indicators. Information technology's all in the taste.

Before nosotros embarked on this examination, we thought we could assess quality by looking at an oyster and its numbers, i.e. its dates and weights. But what this experiment showed u.s.a. is those characteristics tin be deceiving. It doesn't matter if an oyster is live, plump, and full of liquor. It doesn't thing if an oyster was harvested 24 days ago. What matters most is if an oyster tastes good, and to determine that, y'all're just going to have to consume it.